Triple alloy of metals are used for. Metal in dentistry - dental alloys

Any production, from large to the garage, is dealt with metal alloys, and not with pure metals (pure metals are used only in the nuclear industry). After all, even widespread steel is an alloy, which contains up to two percent of carbon, but this nuances will be written in more detail below. This article will describe most alloys, their receipt, basic and useful properties, use and many other nuances.

This article on metal alloys, and we will not be particularly deepened in the Debres of Materials and describe absolutely all alloys, and it is unrealistic within one article. After all, if you go deep into this topic, and touched at least the majority, then you can stretch the article into an immense canvas. Here the most popular alloys will be described from the point of view of automotive industry and motorcycle (according to the subject of the site), although other aspects of industry will be touched by a little.

But besides alloys, it should still write a few words about the metals themselves, more precisely about their amazing property, thanks to which various alloys appeared. And the main property of the metals is that they form alloys, both with other metals and non-metals.

The very concept of alloy is not a completely mandatory chemical compound, because the unique properties of the crystal lattice consist in the fact that part of the atoms of one metal is replaced by atoms of another metal, or two crystalline lattices are embedded in each other.

And at the same time, it turns out as if the wrong alloys, but the most amazing thing is that these irregular alloys are obtained by their properties are much better than pure metals. Moreover, experimenting and manipulating with additives, you can get materials (alloys) at the output with the necessary and useful qualities.

It should be noted that according to the technology of application, all alloys are divided into two large groups. The first group is deformable alloys, of which many parts are manufactured by machining: forging, stamping, cutting, etc. And the second group of alloys is the foundry and of them get parts with casting in forms.

The first group of alloys has such properties as good plasticity in solid form, well, high strength, but foundry in the first group is not high. The second group opposite the casting properties are excellent, they fill out well when casting, but when they are frozen, the strength of them leaves much to be desired.

What is the strength? - This valuable property is estimated by different parameters, which more than ten, but the most valuable property is the strength of the alloy strength during stretching. Speaking by scientific language is the alloy voltage (measured in n / m², well, or in kg / mm²) which corresponds to the greatest load preceding the beginning of the destruction of the test part, relative to the initial cross-sectional area of \u200b\u200bthe part.

And now speaking in a simpler language: take a specially manufactured item (according to the test standard) from the test alloy and securing it in a special machine stretch it, gradually increasing the load until the details are destroyed (its break).

Well, the applied force, (which is controlled by the devices and which was applied to the part, at the very moment before it is gap) divided into the cross-sectional area of \u200b\u200bthe part, and shows the limit of its strength (well, of course the alloy strength of the alloy from which the item is manufactured).

The most common metals on our planet (and of course on their basis the resulting alloys) is iron, aluminum, magnesium and oddly enough for many - titanium. All these metals are in pure form are not used in the technique, but their alloys on the contrary are very common.

Iron and alloys of metals based on it.

Metal iron is the "bread" of the entire global industry. After all, the majority of alloys used in the global industry (more than ninety percent) are used by iron alloys. And a very important additive to iron is not at all the addition of metal, but non-metal carbon.

If you add no more than two carbon percent in the iron, then we get the most popular alloy (alloy number one) is steel. Well, if the carbon content is more than two percent in the iron alloy (from two to five), then get the cast iron, which is also the most important material in the global industry. Now let's stop on the alloys of iron in more detail.

Steel.

Iron alloy with carbon in which carbon contains no more than two percent. It also contains silicon impurities, manganese, phosphorus, sulfur, etc. As mentioned above, is the most important alloy for industry, as it has excellent living and quite high strength.

Whatever details of the car, motorcycle, well, or equipment (at the factory or in a regular garage), we would not throw out, everywhere we will see the presence of steel details. The same elements of the suspension of machinery and motorcycles, body elements, frame, rudders, suspension and hitch of most motorcycles, internal parts, or, and a lot more than something, starting from the most complex parts of various equipment and ending with conventional bolts and nuts.

The tensile strength is from 30 to 115 kg / mm² - this is for carbon steel, well, the tensile strength for alloy steel reaches 165 kg / mm².

Alloy steel is obtained by adding, except carbon, also various alloying elements adding steel of various important and beneficial properties.

• For example, the addition of manganese increases the resistance of steel to shock loads and adds hardness.
• Nickel additive increases corrosion resistance and plasticity, and adds strength.
• Vanadium increases resistance to shock loads, abrasion (reduces the friction coefficient) and also adds steel strengths.
• Chromium in the composition of steel also increases corrosion resistance and strength.

Well, with the addition of chromium and molybdenum in certain proportions, they receive the most durable and militant chromium-molybdenum steel, which is used to produce responsible parts, for example, for the production of sports car and motorcycles.

Well, the top of the metallurgical evolution was the legendary strongest steel "Chromansil" (chromo-silicon-manganese steel) with the highest tensile strength.

And although the latest technology does not stand still and now, in addition to chrom-molybdenum and aluminum frames, they are already manufactured (more precisely) frames from composite materials (the same carbon, kevlar, etc.), but still steel frames other than its strength are also noticeable Cheaper and therefore used so far. Well, most of the internal parts of the engines, gearboxes and equipment (machines) I think for a long time will be made of steel.

Not all components are listed above, the addition of which can significantly improve the properties of steel and when the approach must achieve the necessary and important qualities of steel parts operating in different conditions.

In addition to many advantages, the main of which are strength and hardware, steel has and cons. The first of these is quite high cost and restrictions on the weldability of alloyed steels (use complex welding technology), since the usual "destroy" most of the alloying elements and significantly reduce the strength of the weld.

Well, in most steels (except stainless), another substantial minus is a small resistance to corrosion, although again, with the competent additive of the desired elements, it is possible to significantly increase corrosion resistance.

Steel of different varieties are produced in the form of rolled: stripes, ribbons, sheets, rods (round and hex) profile material, pipes, wire, etc.

By appointment, steel is divided into structural, instrumental and special:

• The structural contains up to 0.7 percent of carbon and make parts of machines, equipment, various devices and fixtures.
• Instrumental steel contains from 0.7 to 1.7 percent of carbon and is used as a rule for the manufacture of various tools.
• Special steel is heat-resistant steel, stainless, non-magnetic and other steel with special properties.

The quality of ordinary quality, high-quality and high quality:

Carbon style constructive steel Contains from 0.08 to 0.63 percent of carbon. The carbon content in each brand of this steel is usually definitely not withstand and the brand is determined by the mechanical properties of this steel.

Of the steel No. 1, sheet and strip material are manufactured, as well as various gaskets, ripples, washers, tanks, etc. And from steel №2 make handles, loops, hooks, bolts, nuts, etc. Of the steel No. 3 and №4, build structures are manufactured as a rule, and from steel No. 7 makes swords, cam clutches, wedges, rails, springs, which are then thermally treated.

Carbon construction high-quality steel Contains up to 0.2 percent of carbon and made from it. Details to which increased requirements for their mechanical properties are presented and for thermally processed parts. This steel has a brand from №8 and up to Steel No. 70. And the number shows approximately the average carbon content in hundredths of interest.

This steel is quite plastic and viscous and thanks to this perfectly stamps and welded. And in the manufacture of parts of working with shock loads, or ending with friction, such parts from this steel cementing. And steel with a carbon content of more than 0.3 percent is not cementing.

From steels of stamps, Article 30 or 35 make nuts, bolts, studs and washers (for responsible structures), and from steels 45 trees, coupling, sleeves and other similar parts that are subjected to heat treatment (hardening and vacation) are made from steels 45. Well, from durable and hard steel, grades of Art 50, 55 and 60 make gears, stars (gear wheels), connecting rods, springs and other parts, which are also exposed to thermal processing.

Carbon structural quality steel, with a high content of manganese, which increases hardness and strength, produce brands from 15g, 20g, 30g and up to 70g or mark with a number 2: 10g2, 30g2 and up to 50g2. Well, the figure facing the letter G again shows the average percentage of carbon (in hundredths of percent). The letter Γ means that manganese in this steel was about 1 percent, and if the letter G is behind the figure 2, then the maintenance of manganese in such a steel is about 2 percent.

From Steel 10G2, 15G and 20G, cementable parts are made, 45G2 rods are made of engine connecting rods, carriage axes, and the valve springs of engines are made from steel 65g.

From structural alloy steel Make parts of machines that should have high strength, acid resistance, hardness (even with severe heating) and other qualities that are achieved by adding alloying components.

A two-digit number that stands at the beginning of the steel grade indicates the percentage of carbon in hundredths. And the letters that stand next are denoted by a doping additive: H - Nickel, X-chrome, C - silicon, in - Tungsten, K - Cobalt, T - Titan, M - Molybdenum, Mr. - Manganese, Yu - Aluminum, D - Copper ... ..

• The chromium additive contributes to increasing the solidity and strength of steel (attacks of corrosion resistance) at the same time sufficient viscosity of steel is preserved. From chromium steels make gear wheels (gears) crankshafts, worms, etc. Details. If the chromium stood up to 14 percent, it perfectly resists corrosion. From such steel, control and measuring and medical instruments are manufactured. Well, if the percentage of chromium is more than 17 percent, then such steel becomes an acid-resistant and stainless.
• Nickel additive increases steel strength and also increases corrosion resistance, and makes steel more viscous (less fragile).
• Silicon additive increases the strength and elasticity of steel and therefore it is added to the spring steel. If a significant content of silicon and chromium has become added, then such steel is called a silhrome and has high heat resistance. Motor valves are made of silch steel.
• The additive of molybdenum and tungsten increases the hardness and strength of steel, and these qualities are preserved at quite high temperatures and therefore cutting tools are made from such steel.

The scores are shown by the percentage of the alloying component. If there are no numbers behind the letter, then the alloying component is contained in the steel only about 1 percent. If at the end of the labeling is the letter A, then this steel is high quality.

Structural steel is produced in the form of sheets, strips and ribbons, pipes, different thickness, as well as rods (round, square and hexagon) in the form of various beams that have different cross-section (brazier, duct, angular, chaveler, etc.).

Various plumbing tools are made of carbon tool steel: chisels, hammers, canvas, files, kerners, beards, rolled, spanners, end heads and another different tool.

Cast iron.

As mentioned above, if the carbon content in the metal alloy (more precisely iron) is contained from two to five percent, then such a material is cast iron. In addition to carbon, phosphorus, silicon, sulfur, and other components are added to the cast iron. Cast iron with special impurities (chrome, nickel, etc.) which give the cast iron special properties, are called doped. Cast iron melting point 1100 - 1200 degrees.

Foundry cast iron is gray, white, high-strength and dwarf.

• Gray cast iron contains carbon in the form of a plate graphite (and part of cementite) and has relatively small hardness and fragility, easily processed by cutting. But thanks to the low cost and excellent casting properties, various columns, stoves, stannes of machine tools, electrical motor hulls, pulleys, flywheels, gear wheels, heating radiators, and many other details are pouring out of gray cast iron. The gray cast iron is denoted by the scores of the sch and two two-digit numbers. For example, the gray cast iron of the sc21-40 brand has a tensile tensile strength of 210 m² (or 21 kgf / mm²) A, with bending, the strength limit is 400 m² (or 40 kgf / mm²).
• White cast iron - in it all carbon is contained in the form of cementite and it gives the white cast iron a greater hardness, but also fragility and this cast iron is difficult to handle cutting.
• High-strength cast iron Contains carbon in the form of inclusions of spherical free graphite (with the addition of cementite) and this gives high-strength cast iron a greater strength, with an equalification with the above-described gray cast iron. The strength of this cast iron increases the addition of alloying components, such as nickel, chromium, molybdenum, titanium. But high-strength cast iron is harder to be treated with cutting than gray cast iron. From this cast iron, the responsible details are cast: blocks, heads, sleeves, pistons and cylinders of engines, compressors, gear wheels and other parts of machinery and equipment. This cast iron is labeled with two letters of the HF and two numbers. For example, the VCh40-10 brand says that it is high-strength cast iron, spank strength of 400 mn / m² (or 40 kgf / mm²) with a relative elongation of 10 percent.
• Dake cast iron is made using a long-lasting tomression dipers (castings) from white cast iron at high temperature, which contributes to burning part of carbon and transition to the rest in graphite. Dake cast iron at the same time receives useful qualities: relatively large resistance of bending, good workability, less density. Movie cast iron make parts of mechanisms that work under conditions of increased stresses and shock loads, as well as working with high pressure steam, water, gases. Make the hinders of the rear bridges and gearboxes of cars, the body of gearboxes of industrial equipment, brake discs, caliper and, valves of water pipes, cartridges and tablets of lathe and other parts. Damnable cast iron with CC letters and two digits. For example, the letters and figures of the KCh45-6 brand mean that such cast iron is duck and has a tensile strength of 450 m² (or 45 kgf / mm²) with a relative elongation of 6 percent.

It is spread in industry (especially in machine-tool in production) at least steel, and its low cost (after all, he is the cheapest of construction materials) Probably one of the main factors of its popularity.

In addition, cast iron, besides its minuses, there are enough useful properties. Foundry cast iron perfectly fills various forms, but one of its main minuses is fragility. But despite the low strength, the cast iron has long been applied in the engine. Not so long ago from the cast iron, engines cast blocks, crankcase parts, crankcaseries of various gearboxes, cylinder sleeves, engine blocks heads, pistons.

By the way, break away from the topic: cast iron pistons, unlike aluminum, have the same expansion coefficient as a cast iron sleeve and therefore the gap of the piston-cylinder can be made minimal, and this contributes to increasing the power and other beneficial properties. Of course, aluminum pistons are significantly easier cast iron and better behave on large speeds and in the aluminum unit with Nicarile coating, but still pistons of various compressors preferably produced from cast iron.

Well, even despite the fact that aluminum blocks with Nicarile coating are now manufactured for modern cars, but still many plants are pig-iron blocks. After all, if you add some graphite to cast iron, you can significantly reduce the coefficient of the piston friction on the sleeve.

But still cast iron engines are gradually crowded, especially motorcycle motor blocks. And all due to the fact that cast iron has another significant minus - it is pretty heavy. And therefore, the blocks (and cylinders) of engines of sports machines and motorcycles already with the twenties are ready last century began to cast from aluminum (aluminum below).

First they made aluminum blocks and cylinders with a cast-iron sleeve, then the cast iron sleeves were refused and now began to cover the walls of cylinders with various solid and wear-resistant electroplating coatings, first chrome, then Niasil, then more complex metal-ceramic compositions, the most advanced of which Keronight, Read more I wrote.

But still the cast iron is used so far, (especially in the machine-tool industry) and especially forging cast iron. After all, the maquetty cast iron is plastic than usual and stronger. The strength of the forging cast iron from 30 to 60 kg / mm² and this allows it to be used not only in the machine tool, but also to produce even parts of machinery and motorcycles, because the brake discs are still made from the maquette of cast iron.

Well, some cast iron brands are still used to make engine crankshafts (for example, B), as well as for manufacture, do not forget that when adding graphite, cast iron rings have a small friction coefficient, and this is important for any engine. Well, more: many probably know that the cast iron head of the engine (despite its greater weight) is less prone to deformation, the more lung aluminum head.

And yet there is still quite a long enough cast iron with the material number two (after steel) in virtually in any heavy industry.

Colored metals and metal alloys.

Despite the fact that the topic of the articles of alloys of metals must be mentioned about non-ferrous metals, based on which most alloys receive. It includes almost all metals besides iron. And they are divided into:

• lights: Rubidium, lithium, sodium, potassium, sodium, cerium, beryllium, calcium, magnesium, titanium and aluminum.
• heavy: lead, zinc, copper, cobalt, nickel, manganese, tin, antimony, chrome, bismuth, arsenic and mercury.
• noble: platinum, gold, silver, palladium, rhodium, iridium, amphibians, ruthenium.
• rare: Molybdenum, Tungsten, Vanadium, Tantalum, Telllur, Selenium, India, Cesium, Germany, Zirconia, etc.

But if you start describing everything, then as already mentioned at the beginning of the article, it will turn into an immense canvas. And only those metals and their alloys will be described below, which are most common and used in auto-motor industry.

Aluminum.

As many people know, it is familiar to humanity to humanity several thousand years, but aluminum is used only a couple of hundred years. And the most interesting thing is that aluminum was first considered to be jewelry, and its production technology and receipt were such expensive that he was considered almost more than silver.

Many people know about how some ruler, having received the aluminum cup from Jeweler, was so amazed by the beauty of this metal and products from it, which began to worry about their silver reserves and that silver will deteriorate due to aluminum. From this poor jeweler was executed, and the cup is reliably hidden.

And probably it would remain this white metal and its alloys by jewelry material, if not the development of aviation. After all, sooner or later, the first aircraft made of wood should have prove their fragility, which happened and then engineers seriously took up the improvement of aluminum production.

And it was worth trying, because this structural material was three times easier than steel. The density of aluminum alloys is from 2.6 to 2.85 g / cm² (depending on the composition). Of course, engineers first collided and so that the mechanical properties of aluminum are not at all high, because the tensile strength is even for casting aluminum alloys from only 15 to 35 kg / mm², and for deformable alloys from 20 to 50 kg / mm² and only for the most expensive and multicomponent alloys strength reaches 65 kg / mm².

And if you compare with steel, then at first glance it will seem that after all the winnings are not at all: the aluminum is three times easier, but in three weaker. But no one has canceled the laws of the conversion and they became a salvation for engineers, because the rigidity of the structural part depends not only on the strength of the material from which it is made, but also from its geometric shape and sizes.

And in the end, it became clear that the aluminum part of the same weight as steel, much more rustling of her torsion and bending. Well, if the stiffness indicators of steel and aluminum parts are the same, then the aluminum item will still be easier by weight, which is needed for aviation and not only for it.

And about the First World War, aluminum alloys began to conquer the world industry. Of course, at the beginning of Aluminum, he poured into the aircraft industry (corps, wings of airplanes), later from it began to cast carts, pistons and not only for aircraft motors, but also cars and motorcycles. And later the cylinder heads and the cylinders themselves began to cast, or the engines of the engines for almost the entire transport.

By the way, the details of the engines did not limit itself and at the end of the twenties of the last century were noticed attempts to make the frame of sports cars and motorcycles from aluminum alloys, as well as the body, but still for a stream for many serial cars and motorcycles such products managed to deliver only By the end of the 80s of the last century.

Well, in modern technology, aluminum parts (except those listed above) can be transferred almost indefinitely - these are the details, both cars and motorcycles (scooters, bicycles), frames, pendulums, steers, traverses, various brackets, up to the trunks on the roof of the car Or on the back wing of a motorcycle. Yes, you never know what.

Well, then it is worth saying about one feature of the aluminum and aluminum metal alloys. Aluminum is very active metal to environmental exposure, but the most interesting thing is that super activity itself and helps him preserve (protect against corrosion). After all, aluminum is so active metal that it instantly reacts with air oxygen (and moisture present in it).

And from this on the surface of the aluminum part instantly the finest oxide film is formed, and it is it that protects any aluminum part from corrosion. Although different alloys, depending on the components, various resistance to corrosion. For example, casting alloys have good protection, but on deformable alloys, the oxide film is very thin and weak and its protective properties depend directly on alloying additives into the alloy.

For example, the well-known and applied in aviation such an aluminum alloy as duralumin, has such a weak oxide film, which very quickly corrodes, covered with white raid, and if it is not covered with a protective coating, then the corrosion of it is quickly "eating."

As a coating, it was previously covered (plated) with thin film of pure aluminum, but now, with a wide development, covered with various coatings of all sorts of fairly bright colors (golden, bright blue, red, etc).

Well, it is still worth writing a few words about aluminum itself - it is a metal with a low density that is well sufficient forging, stamping, pressing, cutting, and besides, it has quite high electric and thermal conductivity. And therefore, it is quite widely used in electrical engineering (electric industry), instrument making, mechanical engineering, aviation, both in pure form and in the form of alloys.

Possessing relatively sufficient strength and hardness of aluminum alloys with copper, manganese, silicon and magnesium is called duralumin, which is mentioned above, is used in aircraft construction, in mechanical engineering and other industries.

Along with duralumin, almost all aluminum-based alloys (like steel) are produced in the form of rolled: stripes, ribbons, sheets, rods (round and hex) profile material, pipes, wire ...

Magnesium.

Probably everyone who kept a piece of this interesting and one of the easiest metals, it seems that it is not a metal that is not at all, but a piece of plastic, so light. Refers to the number of the easiest metals, from the technique used. And its alloys with zinc, aluminum, silicon and manganese are used in the manufacture of various parts of radio equipment, devices, etc.

Previously, this metal was called a fashionable word electron. The density of this metal is four and a half times less than in iron and is only 1.74 g / cm³, and 1.5 times less than that of aluminum alloys. But the strength of magnesium is lower and the tensile limit for melting alloys is from 9 to 27 kg / mm², and for deformable from 18 to 32 kg / mm².

It would seem very small strength, but again, we do not forget that no one has canceled the conversion laws, and very low weight overlaps everything would seem.

But besides low strength, magnesium has more substantial cons, the first of which is a high price. And the details of motorcycles or cars made of magnesium significantly raise their price. But this is not all the cons: pi production of mania very easily flashes with its casting (well, or during welding) and even when it is machined!

In addition, magnesium Well, very unstable to the effects of the environment (to corrosion) and each piece made of magnesium, it has to protect twice from corrosion - first oxidized, and then apply coating (paint or galvanic). But in bad conditions (for example, in the aggressive environment of winter roads), a small scratch on the coating of the magnesium part and it begins to instantly corrode and quickly collapse.

But still too small weight overshadows all cons and magnesium alloys used for the manufacture of expensive parts of cars and motorcycles (and not only). And they began to apply it in the twenties of the last century, and in the 80s its use almost doubled even on serial technique. For example, some are not too responsible details - Carter Cover, Carter Carts, Head Covers and Other Details (by the way, the engine Carter is even our cheapest Soviet car - Zaporozhets was cast from magnesium alloy).

But alloys of magnesium were used and used only for making frames, chassis, wheels and other parts of sports equipment, more precisely, some expensive serial cars and motorcycles, such as elite sportsbiles of the Italian company Agusta, MV AGUSTA F4 750 Serie Oro motorcycle model , which was twice as expensive than sports buyers of the same company, but with aluminum frames, and weight difference was only 10 kg.

But I think in the future, with the development of galvanotechnics and the use of more resistant coatings, the use of magnesium will increase even more.

Titanium.

Well, this is quite an interesting material and the name itself speaks for itself. By the way, it appeared due to the titanic difficulties of his extraction from the earth's crust, especially at the initial stage of its production. At first glance, Titan looks like steel, until you take in your hands and you will not feel that it weighs it is significantly less.

As I mentioned a little higher, a rather complicated technology for extracting it from the earth's crust and determined its high price and a small prevalence. Most metals and alloys have been mined for several centuries, and the metallic titanium was obtained only in 1910 of the last century. And by the 50s of the last century, only more than two tons of titanium was mined on the whole of our planet!

But after the 50s of the last century, with the development of the conquest of space (space technology and high-speed aviation), Titan was the best of construction materials, due to its great strength and lightness (about the unique properties of titanium just below), and its prey began to develop rapidly.

Despite the fact that the titanium is significantly easier than steel (4.51 g / cm³) the strength of its alloys is almost the same as the best alloyed steels (75 - 180 kg / cm²). In addition, in contrast to steel, titanium has excellent corrosion resistance, as its oxide film has high strength. But that's not all: some titanium alloys have a rather high heat resistance.

In addition, titanium alloys are normally welded in a neutral environment, are not poorly processed, well, they have good casting properties. In short, the advantages in titanium abound, and if it would not be a significant minus - his high price, then they would probably have forgotten anything.

And precisely because of the high price, the use of titanium in auto-moto industry is still limited. But on sports technique, which has never been different, the use of titanium is increasing every year. After all, it's no secret that from the space industry, almost all technical achievements smoothly go to auto-moto sport.

And with time from Titan and its alloys, it was started to make parts of the chassis of sports machines and motorcycles, but still most often made from it details of forced engines: valves and their springs, connecting rods and other parts for which the main requirement is high strength and ease. And on the most expensive sports cars from Titanium, even make fasteners (bolts, studs and nuts).

I still have to say that: just as the smooth "flowing" of titanium parts from the space industry was observed, I think later there will be a gradual flow of the use of titanium and for serial cars and motorcycles, however, we will see ...

Copper.

This metal has a relatively large density, has a characteristic reddish color and excellent plasticity. Also, copper has a rather high coefficient of friction, and excellent electric and thermal conductivity.

Due to this property, electrical wiring, contacts, terminals, parts of radio equipment and instruments (up to the soldering iron) are manufactured from copper and its alloys), are used for food industry equipment. Well, thanks to the high friction ratio, copper is used even for the manufacture of various friction overlays of friction friction and copper supplements can be found even in the clutch discs and motorcycles.

But in most cases, clean copper is now quite rarely used in order to save, mainly in the composition of alloys based on it (brass and bronze - about them later) or as coating (by the way, now the copper coating has even become more popular with chromium, for example, on motorcycles Castoma in style Old School of Castomasing - Old School).

But still clean copper, even for coatings, are now rarely used, and therefore will not be particularly lingering on clean copper and then let's go to its alloys.

Brass.

As many people know - this is an alloy of copper with zinc. And zinc, in the composition of this alloy, increases strength and viscosity, and what is important - the alloy hesitates. The brass is widely used due to its relative softness, plasticity, as well as it is perfectly processed with cutting, well sufficiently flexible, stamping, breakdown (stretching) perfectly soldered.

We produce brass in the form of dipers (castings) sheets, strips, rods, pipes and wires. And since the brass (as well as bronze), in contrast to the copper, has a small coefficient of friction, then the sliding bearings are made from castings (or from rods).

Also quite widely apply brass in the manufacture of various devices. Well, thanks to a rather high anti-corrosion resistance of brass, it is widely used in the plumbing: various bushings (splits, couplings) water taps, valves, etc. And from thin leafs of brass make various adjustment pads.

Well, in addition to corrosion resistance, the brass also has excellent thermal conductivity and therefore from her (along with aluminum) make radiators, from the tubes they make tubes of radiators and various pipelines in industry.

Bronze.

Bronze is an alloy of copper with aluminum, tin, manganese, silicon, lead and other metals. Bronze is a more fragile and solid material, the higher the brass described, but it has an even lower friction coefficient and is therefore more often used in sliding bearings.

The highest quality and valuable is tiny bronze, which has more useful qualities, since the tin in the composition of the alloy increases the mechanical properties of bronze (makes it less fragile) and adds corrosion resistance to bronze, well, and makes this alloy even more slippery (increases antifriction properties) . From tin bronze, the highest quality and sufficiently durable sliding bearings (along with babbiti) are manufactured.

Bronze is perfectly processed with cutting and soldering well, but it is more expensive than brass. As mentioned above, the gliding bearings are most often made from bronze, various sleeves, as well as parts under pressure to 25 kg / cm². Produced bronze, like brass, in the form of rods, strips, wires, tubes, castings, etc.

Babbiti.

These alloys have a very low friction coefficient (if with a lubricant, the friction coefficient is only 0.004 - 0.009) and a rather low melting point (only 240-320 degrees). And therefore, babbits are most often used to fill the rubbing surfaces of the sliding bearings. And since the melting point of babbitis is quite low, they do not use them in the engines, and most often for the bearings of the knees.

In the alloys of babbit, the main component is tin and in the highest quality babbit brand B83 contains 83% tin. Also developed substitutes for babbittes (for example B16) with a lower tin content, which are cast on a lead basis with the additives of arsenic and nickel are BN and BT and other metal alloys.

Lead.

This metal and alloys based on it (for example, solders) has a relatively low melting point (327.46 ° C) and silver-white (with a bluish chip) color. It has good viscosity (forging) with excellent foundry properties. But it is very soft, it is easily cut by a sharp knife and even scratched a nail. A rather heavy metal (has a density of 11.3415 g / cm³, and with an increase in temperature, it drops its density.

The strength of this metal is very small (tensile strength - 12-13 MPa (MN / m²). Recently and is applied with deep antiquity, since he had a small melting point and was often used to cast pipelines in the Kremlin and ancient Rome (there in the same place Ancient Rome, its production reached large volumes - about 80 thousand tons per year).

Lead and its compounds are toxic and especially water-soluble poisonous, such as lead acetate, well, volatile compounds, for example, tetraethylswin. And during the casting of water pipes in ancient Rome and the Kremlin, no one knew about the harmfulness of lead and water passing through lead pipelines, significantly reduced the lives of people.

Now the main use of lead is a casting of lattice batteries, as well as it is used for the manufacture of sheets (cameras) protecting against X-ray radiation in medicine. And lead alloys, antimony and tin are used in decorative casting (then the figures are coated with copper), as well as for the manufacture of sliding bearings (see above Babbit) and for various soldering soldering.

Solid alloys of metals.

These are alloys based on refractory tungsten carbides, vanadium, titanium and these alloys are characterized by high strength, hardness and durability, even at elevated temperatures. Used solid alloys most often for the manufacture of working parts of the cutting tool (, cutter, etc.).

Cobalt-tungsten solid alloys We are produced under the brand from VK2, VK3 and up to VK15. The figures in the marking indicate the percentage of cobalt in the alloy, and the rest is usually carbide tungsten.

Titanium-tungsten solid alloys The marking figures indicate the percentage of cobalt and titanium, and the rest is tungsten carbide (T5K10, T15K6).

That's it seems to be all. Of course, in one article, it is unrealistic to describe the whole lot of useful and interesting facts associated with various metals and alloys of metals, but still, I hope that many metal (materials) forgive me, because it is impossible to argue immense, success!

Metallurgy in our life takes an extremely important role. No, not every one of us belongs to the glorious class of steelovers, but we are working daily with products from metals. As a rule, they are made of a wide variety of alloys. By the way, what is it?

Main definitions

In general, metal alloys are materials obtained by the method of smelting, in the production of which two or more metallic elements were used (in the chemical sense), as well as (optional) special additives. One of the first materials of this kind was bronze. It contains 85% of copper and 15% tin (80:20 in the case of bell bronze). Currently, there are several varieties of this compound, which contains at all there are no tin. But they are not so often.

It is necessary to clearly understand that the alloys of metals in most cases are formed at all without a person. The fact is that the material is absolutely pure from a chemical point of view can only be in the laboratory. In any metal, which is used in living conditions, probably there are traces of another element. Classic example - gold jewelry. Each of them has a certain proportion of copper. However, in the classical sense, this definition still understands the connection of two or more metals, which was targeted by a person.

The entire history of a person is an excellent example of how metal alloys were able to have a huge impact on the development of our entire civilization. It is not by chance that there is even a long historical period called "Bronze Age".

General characteristics of metal alloys

And now we will look at the general properties of metals and alloys that are characterized by. They are very often able to meet in specialized literature.

Characteristic	Decoding
Strength	Alloy ability to resist mechanical loads and resist destruction.
Hardness	The property that determines the material resistance to attempts to implement in its thickness item from another alloy or metal.
Elasticity	The ability to restore the initial form after the application of a significant mechanical effort, the load.
Plastic	On the contrary, this property characterizing the possibility of changing the shape and the size under the action of the applied force, mechanical load. In addition, it also characterizes the ability of the part to maintain the newly acquired form over a long time.
Viscosity	- metal ability to resist rapidly increasing (shock) loads

This qualities are characterized by metal alloys. The table will help you to figure it out.

Production information

In principle, currently under the "alloy" may well be understood by the material, which is based on only one chemical element, but "diluted" by a whole package of additives. The most common way to obtain them, the melting to the liquid state has changed little with deep antiquity.

For example, the analysis of metals and alloys shows that the ancient Indians captured amazing for its time level of metal processing. They even began to create alloys using refractory zinc, which in our time is quite a time consuming and complex procedure.

Today, powder metallurgy is also quite widely used for these purposes. Especially often, ferrous metals and alloys are treated with this method, since in this case it often requires the maximum cheapness of both the process itself and the products.

Spread alloys in the modern industry

It should be noted that all metals that are intensively used by the modern industry are precisely alloys. So, more than 90% of the whole iron produced in the world goes to the manufacture of cast iron and various steels. This approach is explained to the case that the alloys of metals in most cases demonstrate the best properties than their "progenitors".

So, the yield strength of pure aluminum is only 35 MPa. But if it adds 1.6% of copper, magnesium and zinc in a ratio of 2.5% and 5.6%, respectively, this indicator can easily exceed even 500 MPa. In addition, it is possible to significantly improve the properties of electrical conductivity, thermal conductivity or others. There is no mysticism in this: in alloys, the structure of the crystal lattice changes, which allows them to acquire other properties.

Simply put, the amount of this kind of materials today is great, but it constantly continues to grow.

Main classification information

In general, there are no special difficulties here: the compounds in which non-ferrous metals and iron-based alloys are used. Below we will analyze both these categories on the example of the main species, as well as discuss the scope of their use in the modern industry and in production.

Become

All iron compounds containing up to 2% of carbon are called stools. If the composition is found chrome, vanadium or molybdenum, they are called doped. With these materials, we are constantly confronted, daily and hourly. The number of steels today is that one list of enumeration could take not too thin book.

Oddly enough, the lead has long been known to the cooks and restaurateurs, as it was often a dining room and appliances. The alloy that was used for this is called the Puteter. It includes approximately 85-90% tin. The remaining 10-15% as the lead occupies a lead (standard alloy of two metals).

The techniques are also known to Babbiti. These are also lead-based compounds, which also includes tin, as well as arsenic and antimony. These alloys are very poisonous, but due to some special qualities they are actively used in the bearing industry.

About light alloys

As we have already spoken, the properties of metals and alloys are distinguished by the fact that in many cases the characteristics are higher. This is especially noticeable in relation to the modern industry. In recent years, it requires a huge amount of light alloys, which have increased mechanical strength, as well as resistant to the effects of adverse factors of the external environment and high temperatures.

Most often, aluminum, beryllium, as well as magnesium is used for their production. The compounds based on aluminum and magnesium are especially claimed, since their sphere of possible use is extremely wide.

Aluminum-based alloys

As we have already spoken, without them the modern industry is decisively impactable. Judge for yourself: aluminum alloys are actively used in aviation, space, military, scientific and engineering and other industries. Without aluminum, it is impossible to imagine producers of modern household and mobile techniques, since the hulls from this metal are increasingly used by the modern flagships of these industries.

What are they?

Aluminum alloys are divided into three large groups:

• Foundry (Al - Si). Especially widely distributed in the automotive industry and military industry.
• Alloys intended for injection molding (Al - Mg).
• Compounds of increased strength, self-tapping (Al - Cu).

Advantages and disadvantages of this material

Many alloys from this material are economical, relatively inexpensive and very durable, since they are not corrosion. Different with high strength in conditions of extremely low temperatures (aerospace industries) and a very simple processing process. It does not require particularly complex and expensive equipment for their forming, as they are relatively plastic and viscous (see the table with characteristics).

Alas, but they have their drawbacks. Thus, at temperatures above 175 ° C, the mechanical properties of aluminum and alloys based on it begin to deteriorate rapidly. But due to the presence of amalgam on their surface (protective film from aluminum hydroxide), they have outstanding resistant to the action of aggressive chemical media, including acids and alkalis.

They have excellent electrical conductivity and thermal conductivity, non-magnetic. It is believed that they are absolutely harmless to human health, and therefore they can be used to produce food dishes and cutlery. However, the latest physician researchers still say that aluminum compounds in some cases can provoke Alzheimer's disease.

The military fell in love with these materials for the fact that they do not give sparks even with sharp mechanical impacts and blows. In addition, they perfectly absorb shock loads. Simply put, some of these alloys of metals (the composition of which is most often classified) are actively used to produce lightweight armor for equipping a variety of BTR, BMP, BRDM and other techniques.

Thanks to all these properties, alloys based on everywhere are used for the production of pistons for internal combustion engines, as well as in the production of building structures (corrosion resistance). Aluminum and materials based on it in the production of reflectors for lighting representations, electrical wiring, as well as for the manufacture of various equipment (not magnetized).

It is important to note that even in theoretically pure aluminum sometimes contains a significant admixture of iron. It can contribute to a higher mechanical strength of the material, but its presence makes an aluminum-based alloy strongly subject to corrosion processes. In addition, the alloy largely loses its plasticity, which is also not too good in most cases.

Loosen the negative effect of iron impurities helps cobalt, chrome or manganese. If the alloy includes lithium, then it turns out very durable and elastic material. It is not surprising that such a connection is very popular in the aerospace industry. Alas, but lithium alloys with aluminum have an unpleasant property, which again is expressed in poor plasticity.

Let's summarize some results. It turns out that the main alloys of metals in astronautics, aviation and other high-tech industries are in their composition aluminum. In general, this is exactly the situation today, but often in the modern industry is used magnesium and its alloys.

Magnesium alloys

They have an extremely low mass, and also characterized very impressive strength. In addition, it is these materials that are superbly suitable for the foundry industry, and the billets are perfectly amenable to turning and milling processing. And therefore they are actively used in the production of rockets and aircraft turbines, instrument housings, automotive wheels, as well as some varieties of armored steel.

Some varieties of these alloys are distinguished by excellent indicators of viscous damping, and therefore they go to the production of parts and structures that have to work in the conditions of an extremely high level of vibrations.

Advantages and disadvantages of magnesium alloys

They are pretty soft, relatively well resist wear, but differ not too impressive plasticity. But they are distinguished by excellent adaptability to molding under conditions of high temperatures, well adapted to connect using all existing species of wags, and can also be connected by bolting, riveting and even gluing.

Alas, but all these alloys do not differ in particular resistance to the effects of acids and alkalis. Extremely negatively affects a long stay in seawater. However, magnesium alloys are surprisingly stable in the conditions of the air environment, so many of their flaws can be neglected. If it is necessary to reliably protect such parts from corrosion, then apply chromium coating, anodizing or similar methods.

They can be plated with nickel, copper or chromium, pre-immersed in the melt of chemically pure zinc. In such a processing, the indicators of their strength and resistance to abrasion increase dramatically. It is necessary to recall that magnesium is rather active from a chemical point of view of metal, and therefore, when working with it, it is necessary to comply with at least basic security measures.

Thus, the production of metals and alloys is a key feature of the modern industry. Every year, people invent more and more ways to obtain new materials, so soon we will probably get completely incredible compounds that will combine the beneficial properties of several materials and chemical elements at once.

Definition

Alloys - This is a mixture of two or more elements, among which metals are dominated. Metals included in alloy call the base. Often, non-metals add special properties to alloy to alloy, they are called alloying or modifying additives. Among alloys, iron and aluminum-based alloys have the greatest significance.

Alloy classification

There are several ways to classify alloys:

• according to the method of manufacture (cast and powder alloys);
• by the method of obtaining a product (foundry, deformable and powder alloys);
• in composition (homogeneous and heterogeneous alloys);
• according to the nature of the metal - the bases (black-and-similar Fe, colored - the base of non-ferrous metals and alloys of rare metals - the basis of radioactive elements);
• in terms of components (double, triple, etc.);
• according to characteristic properties (refractory, low-melting, high-strength, heat-resistant, solid, antifriction, corrosion-resistant, etc.);
• for appointment (structural, instrumental and special).

Properties of alloys

The properties of alloys depend on their structure. For alloys, structural-insensitive are characteristic (are determined by the nature and concentration of elements constituting alloys) and structural-sensitive properties (depend on the characteristics of the base). The structural and insensitive properties of alloys include density, melting point, heat of evaporation. Thermal and elastic properties, thermal expansion coefficient.

All alloys exhibit properties characteristic of metals: metal shine, electric and thermal conductivity, plasticity, etc.

Also, all properties characteristic of alloys can be divided into chemical (the ratio of alloys to the effects of active media - water, air, acid, etc.) and mechanical (the ratio of alloys to the effects of external forces). If the chemical properties of alloys are determined by placing an alloy into an aggressive environment, special tests are used to determine mechanical properties. So, to determine the strength, hardness, elasticity, plasticity and other mechanical properties conduct tensile tests, creep, shock viscosity, etc.

The main types of alloys

Wide use among all sorts of alloys found various steel, cast iron, copper, lead, aluminum, magnesium alloys, and light alloys.

Steel and cast iron - iron alloys with carbon, and the carbon content in steel to 2%, and in cast iron 2-4%. Steel and cast iron contain alloying additives: steel-CR, V, Ni, and cast iron - Si.

Different types of steels are isolated, so, the design, stainless, instrumental, heat-resistant and cryogenic steel is isolated by destination. By chemical composition, carbon (low-, medium and high-carbon) and alloyed (low-, medium and high-alloyed) are isolated. Depending on the structure, austenitic, ferritic, martensitic, pearlit and beynic steel are isolated.

There were use in many sectors of the national economy, such as building, chemical, petrochemical, environmental protection, transport energy and other industries.

Depending on the form of carbon content in cast iron - cementite or graphite, as well as their quantities distinguish between several types of cast iron: white (light color of the breakfall due to the presence of carbon in the form of cementite), gray (gray blonde due to carbon presence in the form of graphite ), mappy and heat-resistant. Castings are very fragile alloys.

The areas of the use of cast iron are extensive - articular decorations (fences, gates), cabinet parts, plumbing equipment, household items (frying pans) are manufactured (frying frying), it is used in the automotive industry.

Copper-based alloys are called brass, as additives, they contain from 5 to 45% zinc. Brass with a content from 5 to 20% zinc is called red (Tompac), and with a content of 20-36% Zn - yellow (alpha brass).

Among the alloys based on lead, two-component (lead alloys with tin or antimony) and four-component alloys (lead alloys with cadmium, tin and bismuth, lead alloys with tin, antimony and arsenic), and (typical for two-component alloys) with different content of the same components Get different alloys. So, an alloy containing 1/3 lead and 2/3 of tin - a redtar (ordinary solder) is used for soldering pipe and electrical wires, and an alloy containing 10-15% lead and 85-90% tin - Pewer, previously applied to casting cutlery.

Alloys based on aluminum two-component - Al-Si, Al-Mg, Al-Cu. These alloys are easy to receive and process. They have electrical and thermal conductivity, non-magnetic, harmless in contact with food, explosion-proof. Aluminum-based alloys have found application for the manufacture of light pistons, apply to cargo, car and aircraft construction, food industry, as architectural and finishing materials, in the production of technological and household conduits, when laying high-voltage power lines.

Examples of solving problems

Example 1.

Example 2.

The task	Under action on the Al and FE mixture, weighing 11 g excess HCl, 8.96l gas was released. Determine the massive lobes of metals in the mixture.
Decision	Both metal are introduced into the reaction of the interaction, resulting in hydrogen: 2AL + 6HCl \u003d 2AlCl 3 + 3H 2 Fe + 2HCl \u003d FECL 2 + H 2 Find the total amount of moithing hydrogen: v (H 2) \u003d V (H 2) / V M v (H 2) \u003d 8.96 / 22.4 \u003d 0.4 mol Let the amount of substance Al - x mol, and Fe -y mol. Then, based on the reaction equations, you can record the expression for the total number of mooss of hydrogen: 1.5x + y \u003d 0.4 We will express the mass of metals in the mixture: Then, the mixture mass will be expressed by the equation: 27x + 56u \u003d 11 Received a system of equations: 1.5x + y \u003d 0.4 27x + 56u \u003d 11 I solve it: (56-18) y \u003d 11 - 7.2 v (Fe) \u003d 0.1 mol x \u003d 0.2 mol v (AL) \u003d 0.2 mol Then, the mass of metals in the mixture: m (AL) \u003d 27 × 0.2 \u003d 5.4 g m (FE) \u003d 56 × 0.1 \u003d 5.6 g Find mass fractions of metals in the mixture: ώ \u003d M (ME) / M SUM × 100% ώ (Fe) \u003d 5.6 / 11 × 100% \u003d 50.91% ώ (AL) \u003d 100 - 50.91 \u003d 49.09%
Answer	Mass shares of metals in the mixture: 50.91%, 49.09%

Metal alloys are sophisticated in the composition of the composition formed as a result of the interaction of two or several metals or metals with some non-metals. Chemical elements or their stable compounds included in

alloy, customized components. Alloys can consist of two, three or more components.

The component prevailing in the alloy is quantitatively called the main one. The components entered into the alloy to give it the desired properties are called alloying. The combination of the components of the alloy is called the system.

Alloys are classified according to the number of components - on double (binary), triple, fourth and multicomponent; on the main element - iron, aluminum, magnesium, titanium, copper, etc.; for use - structural, instrumental, heat-resistant, antifriction, spring, ball beads, etc.; on density - heavy (based on tungsten, rhenium, lead, etc.), light (aluminum, magnesium, beryl, etc.); on the melting point - refractory (niobium-based alloys, molybdenum, tantalum, tungsten, etc.), low-melting (solders, babbits, typographic alloys, etc.); According to the manufacture of semi-finished products and products - foundries, deformable, sintered, granular, composite, etc.

The ability of various metals to form alloys is far from the same; The structure of the alloys after their hardening may also be the most diverse.

Metal alloys in liquid state are usually homogeneous and represent one phase.

Phase They call a homogeneous part of the inhomogeneous system separated from its other parts of the section. When moving alloys from a liquid state to solid, several phases may form. After solidification, depending on the nature of the components of the alloys may consist of one, two and more solid phases. It is possible to form solid solutions, chemical compounds and mechanical mixtures consisting of two or several phases.

Solid solutions They call alloys (of two or more components), in which the atoms of the soluble component are arranged in the crystal lattice of the solvent component. In the formation of a solid solution, the solvent is called that metal, the crystalline grid of which is preserved as the basis. If both metal have the same as the type of crystalline lattices and as a result of this, an unlimited mutual solubility in a solid state (forms a continuous series of solid solutions), then the solvent is that of which the concentration of which in the alloy exceeds 50% (atomic).

To form a continuous series of solid solutions, the same type of component crystal lattices is necessary and a small difference between crystalline lattices.

The solid substitution solution is formed by replacing the part of the solvent atoms in its crystal lattice atoms of the dissolved component (Fig. 1.6, but). These solutions can be limited and unlimited.

In solid solutions, diffusion transitions of components from places with greater concentration in places with a smaller concentration can occur as long as the concentration becomes the same in all volumes. However, diffusion in solid solutions proceeds much slower than in liquid, and its speed decreases with a decrease in temperature.

There are three types of solid solutions: replacement, introduction and subtraction. Consider only the first two types of solid solutions, since solid solutions of subtraction occur relatively rarely.

Fig. 1.6. Scheme for the formation of solid solutions: O - atom of base metal (solvent); - Dissolved Metal Atom

Typically, components in which atomic periods of the lattice differ no more than 8%, form an unlimited range of solid solutions of substitution; by 8-15% - solid solutions of substitution with limited mutual solubility; More than 15% - do not form solid solutions.

The solid implant solutions are formed by placing the atoms of the dissolved component in the free gaps between the atoms of the solvent's crystal lattice (Fig. 1.6, b).

Chemical compounds are formed with a strictly defined quantitative ratio of alloy components and are characterized by a crystal lattice, different from the lattices of the source components. Chemical compounds, as a rule, have characteristic physicomechanical properties: high hardness, increased fragility, high electrical resistance.

Chemical compounds in alloys are formed between metals (intermetallic compounds), as well as between metals and non-metals. Some compounds of metals with non-metals (carbides, nitrides, oxides, phosphides, etc.) obtained independent use in the technique.

Mechanical mixtures are formed by simultaneously falling out of the liquid melt when it is cooled by the crystals of the components of its components (eutectic mixtures). In crystals, which are part of the mechanical mixture, the crystal lattice of the initial components of the alloy is preserved. Mechanical mixtures can consist of pure components, solid solutions, chemical compounds, etc.

The phase rule (Gibbs law) establishes a quantitative relationship between the number of freedom degrees, the number of phases and the number of components. Under the number of degrees of freedom of system, the number of independent external (temperature, pressure) and internal (concentration) of variables, which can be arbitrary without changing the number of phases in the system are understood.

For metal alloys under constant pressure, variable values \u200b\u200bare temperature and concentration. In this case, the phase rule takes the following form:

where the number of degrees of freedom; TO- number of system components;

F - Number of phases.

When crystallization of pure metal, the system consists of one component (K \u003d. 1), solid and liquid phases (F \u003d 2). With a constant pressure, such a non-vintage system (the number of degrees of freedom is zero) and it is impossible to arbitrarily change the temperature without changing the number of phases.

For pure molten metal (K \u003d. 1, f \u003d 1, C \u003d. 1) System is monovariant, i.e. When the temperature changes, the equilibrium of the system will not break.

• These provisions are not ill. For example, in the selenium-teleurur system (the difference in incidence of 17%) is formed an unlimited series of solid solutions. There are iders exceptions.

Metal in dentistry occupies a central place among the materials. Of the dental alloys they cast (or stamps) most of the unable prostheses, the framework of removable prostheses. Alloys in dentistry are used as auxiliary materials, for soldering and stamping. Of them make dental instruments.

Article Article:

• Classification of metals and alloys in dentistry
• Structural alloys of metals in orthopedic dentistry
• Noble alloys of metals in dentistry
• Officon alloys in orthopedic dentistry
• Auxiliary alloys of metals in dentistry

Metals and alloys in dentistry Classification

All metals and alloys are divided into black and colored.

Black metals - This is iron and alloys based on it. Steel and cast iron. Cast iron contains more than 2.14% of carbon. In dentistry does not apply.

The surface of the cast iron matte and unfinished. He is poorly polished.

iron-based alloy containing less than 2.14% carbon. In addition to iron and carbon, other metals are also present in steel. They give the alloy new properties (alloy steel), including make it stainless.

Steel caps for stamping crowns

- Alloy of iron and carbon, with the addition of any other metals. They change the properties of the alloy (melting point, hardness, plasticity, pupidity, etc.).

- Steel resistant to corrosion. As an anti-cariological agent, chromium (21%), as well as other metals, is most often used.

- This is respectively all other metals.

Metals in orthopedic dentistry are divided into noble and not noble.

Noble metals (or precious metals) - corrosion-resistant metals and chemically inert. The main noble metals are gold, silver, and platinum group metals (platinum, palladium, iridium, osmium, etc.).

Officon metals - Metals, easily subjected to corrosion, and not occurring in nature in its pure form. They are always mined from ores.

Depending on the density

metals used in dentistry are light and heavy.

There is no single point of view in this matter. The most common criterion - the density of the metal is greater than the density of iron (8g / cm³) or atomic weight more than 50 A.M. If at least one condition is performed - the metal is heavy.

For ecology and medicine heavy metals These are metals that have high toxicity and environmental significance. What creates even greater confusion. For example, gold with a density of 19.32 g / cm³ and atomic weight 197 A.E.M. Not refer to heavy metals, due to its inertia and excellent biocompatibility.

Dental alloys of metals Classification

For the purpose of the alloys of metals in orthopedic dentistry divide on:

• A. Construction - of them make dentures.

• B. Alloys for sealing - amalgam.

• B. Alloys, for the manufacture of dental instruments.

• G. Auxiliary. Metals used for other purposes (for example, low-melting metals for stamping or solders).

By chemical composition of alloys used in dentistry happens:

• Alloys of noble metals

• Alloys of ignorable metals

Noble metals in dentistry and alloys

Noble metals in dentistry are expensive. But despite this, they continue to be applied due to excellent biocompatibility. They are not subject to corrosion, do not react with saliva, do not cause allergies and intoxication.

Golden alloy can often be the only option for patients with polyethological contact allergies.

Noble alloys are durable. The only flaw (except prices) is soft and abrasion exposure.

Gold alloys in dentistry.

• Alloy of gold 900 sample. (ZLSRM-900-40).

STRUCTURE: 90% gold, 4% silver, 6% copper.

Properties: Melting point 1063 ° C.

The alloy is distinguished by plasticity, it is easy to mechanically machining under pressure (stamping, rolling, forging).

Due to low hardness, the alloy is easily erased. Therefore, in the manufacture of stamped crowns from the inside, on the chewing surface or cutting edge, poured solder.

Release: In the form of disks with a diameter of 18, 20, 23, 25mm and blocks of 5g.

Application: For stamped crowns and bridge prostheses from

alloy noble metals in orthopedic dentistry

• Gold alloy of the 750th sample (ZLSRPLM-750-80)

Consists Gold - 75%, silver and copper 8%, and platinum - 9%

Platinum gives this alloy elasticity and reduces the shrinkage when casting.

Apply For the manufacture of cast gold parts of burealed prostheses, clammers and tabs

• The alloy of gold dental 750 sample (ZLSRKDM)

IN structure Added cadmium - 5-12%.

Due to the cadmium, the melting point of the alloy is reduced to 800 C. (Average melting point of gold alloys 950-1050 C.) What allows you to apply this alloy as solder.

Silver-palladium alloys are different than more than \u003d 1100-1200 C. Their physicomechanical properties are similar to gold alloys. But corrosion resistance is lower. (Silver darkens with contact with sulfur compounds) plastic and dagging alloys. Sold out the golden solder (ZLSRKDM).

• Alloy PD-250

STRUCTURE: 75.1% of silver, 24.5% palladium, slightly alloying metals (zinc, copper, gold).

Apply For stamped crowns. Release according to the disks of various diameters (18, 20, 23, 25 mm) and a thickness of 0.3 mm.

• Alloy PD-190

Structure: 78% of silver, 18.5% palladium, other metals.

Apply As an alloy for casting in dentistry.

• Alloy PD-150

Reduced Number of palladium to 14.5%, increased silver.

Apply For tabs.

Ungrevious alloys of metals used in orthopedic dentistry

To reduce the cost of prosthesis, alloys were developed, based on cheaper metals to replace the expensive gold.

In the USSR, the most widely used cheap stainless steel.

Today, cobalt-chrome and nickel-chrome alloys occupy the bulk of the wound.

Alloy stainless dental-steel dental

Steel is the most common alloy in the world. Its properties are well known. And at the expense of alloying agents, it can be given any properties.

Stool dental is very cheap.

From disadvantages: Steel is heavy (density of about 8 g / cm3) and chemically active. May cause allergies, Galvania.

Stainless steel in the dentistry orthopedic - brand:

• Steel brand 1. X. 18 H. 9T (EHA-1)

Dental raf fusion STRUCTURE:

1.1% carbon; 9% nickel; 18% chromium; 2% manganese, 0.35% titanium, 1.0% silicon, the rest - iron.

Applyfor non-removable prosthesis: individual crowns, cast teeth, facets.

• Steel brand 20x18n9t

STRUCTURE: 0.20% carbon, 9% nickel, 18% chromium, 2.0% manganese, 1.0% titanium, 1.0% silicon, the rest is iron.

From this type of steel in the factory, they are manufactured:

• standard sleeveswalking on the production of stamped crowns;

• billets of clamps(for CSPP)

• elastic metal matrices for sealing, as well as separation strips

• STEELfor dentistry Brands 25x18N102S.

STRUCTURE: 0.25% carbon, 10.0% nickel, 18.0% chromium, 2.0% manganese, 1.8% silicon, the rest - iron.

Application: In the factory conditions, they are manufactured:

• teeth(side upper and lower) for stamping resistant pavement prostheses;

• orthodontic wire diameter from 0.6 to 2.0 mm (step 0.2mm)
  .

The Silver Solder of PSR-37 or Solder Zetrin is used as a solder for non-dense alloys.

Contains silver-37%, copper - 50%, manganese - 8-9%, zinc - 5-6%

Melting point - 725-810 with

Cobalt chrome alloy in dentistry

(cobalt-chrome alloy, chromocobalt alloy)

STRUCTURE:

• cobalt 66-67%, the base of the alloy, solid, durable and light metal.
• chromium 26-30% introduced mainly (as in steel) to increase corrosion resistance.
• nickel3-5%, raises the plasticity, mortality, alloy viscosity, improves the technological properties of the alloy.
• molybdenum 4-5.5%, increases alloy strength.
• manganese 0.5%, increasing strength, casting quality, lowering melting point, which helps remove sulfur toxic compounds from alloy.
• carbon 0.2% reduces the melting point and improves the liquid process of the alloy.
• silicon 0.5%, improves the quality of castings, increases the liquid process of the alloy.
• iron0.5%, increases liquid process, improves casting quality.

The properties of the KHS-alloy dental:

It has good physical and mechanical properties, low-density (and respectively by the weighing of restorations) and excellent liquid process, allowing to cast high strength openwork products.

The melting point is 1458 with

The alloy is resistant to abrasion and long retains the mirror glitter.

Cobaltchromic alloy in dentistry

It is used in for cast crowns, bridge-shaped prostheses, solo-grained bureaucratic prostheses, metal-ceramic prosthetic frames, removable prostheses with cast bases, covert devices, cast clums.

Metal ceramics Metal composition in dentistry

Celebrate - Cobalt-chrome

metal Alloy

metal ceramics in dentistry.

Alloys in which the main element Ni. Elements of this alloy except nickel - SG (at least 20%), CO and Molybdenum (MO) (4%).

By properties, the nickel alloy is close to the cobalt alloy.

It is used: for casting of fixed prostheses and frameworks of removable prostheses.

Today, the use of nickel alloys due to their high allergy is limited.

Titanium alloys in orthopedic dentistry

In dentistry, both pure titanium (99.5%) and its alloys are used.

Pure titanium

For casting and milling, titanium, aluminum and vanadium alloys are used (90-6-4%, respectively). And titanium alloy with aluminum and niobium (87-6-7%).

Titanium alloys are lung and amazingly durable. But refractory and heavy in processing.

In orthodontics, alloys of titanium, vanadium and aluminum (75-15-10%) are used to manufacture arcs.

Metals used in orthopedic dentistry

Nickel and Titanium alloy - nickelid Titan - Nickel 55%, Titan 45%.

The alloy has a form memory. Deformed chilled products from this alloy when heated acquire the source form.

The alloy is applied in orthodontics, where under the action of body temperature it takes
It is necessary.

Also from it make endodontic tools with form memory.

Auxiliary alloys used in orthopedic dentistry

Bronze - Alloy copper with tin. In dentistry, aluminum bronze (aluminum instead of tin) is used. From it make ligatures to shining jaw fractures.

Brass - Copper alloy with zinc - from it makes pins for folding models.

Magnalia - Aluminum and magnesium alloy - from it the details of the aircraft (the alloy is very light and durable). In dentistry, articulants and some cuvettes are made of it.

Amalgama - Metal alloy with mercury. Used for sealing.

The topic is too extensive, the Amalgam in dentistry will be a separate article.

Long-melting alloys in the dentistry of orthopedic

Alloys Legging (Mellota, Wood, Rose) - contain brazut, tin, lead

- their melting point of about 70 C.

Used for stamps when stamping crowns, counter stamps, manufacturing collapsible models.

Lightweight metals in dentistry

Wood alloy.

Melting point 68 C.

Ingredients: bismuth - 50%, lead - 25%, tin - 12.5%, cadmium - 12.5%.

Toxic, as it contains cadmium.

Mellota alloy.

Melting point 63 with

Composition: bismuth - 50%, lead - 20%, tin - 30%.

Rose alloy for dentistry.

Melting point 94 C.

Composition: bismuth - 50%, lead and tin 25%.

Tool Steel. - Contains carbon from 0.7% or more.

Differs high strength and hardness (after special temperature processing).

Adding to tungsten steel, molybdenum, vanadium and chromium makes steel capable of cutting at high speed. Such steel is used for bors and cutters.

Wolfram carbide - not alloy. Chemical compound of tungsten with carbon (chemical formula WC). Main on hardness with diamond. Apply for the production of armor-piercing tank shells. And also for carbide dental bors.

Zirconia dioxide - Also not alloy. Chemical compounds of zirconium metal with oxygen. In the chemical nature is close to ceramics, but hard and stronger. In dentistry used for the manufacture of milled prostheses.

Metal alloys used in dentistry (conclusion)

It is impossible to present modern dentistry without metals. They are at the heart of everything. And there is no material that could replace the metal.

Application of metals in dentistry

Metals in dentistry are used for:

• Crowns and bridge prostheses
• Frames of Burel Prostestures
• Metal Bases CHSPP and PSPP
• Dental implants
• For tools and fixtures
• As auxiliary material for various technological processes
• For sealing

Video: Metal with shape memory in medicine

Metal in dentistry - dental alloys Updated: February 4, 2017 by the author: Alexey Vasilevsky