Silumin - what is this alloy and where is it used?

Tin-aluminum alloy

Tin is a common metal in nature, but its alloys, such as tin and aluminum, are also popular.
When combined with tin, pure metals acquire improved properties as before the smelting process.

In its pure form, tin is used to create various products for the food, light, aviation, radio engineering, textile, etc. industries. industry. Aluminum is common in thermal structures, cryogenic technology, and light industry.

Aluminum and tin are very different elements. Aluminum is light and easily soluble in acids, so the smelting procedure is very difficult. But due to its positive properties, this alloy is often used in industry.

The alloy system is one of a kind. The alloy becomes solid at 650 ºС, but tin remains liquid up to 225 ºС. In order to eliminate the problem, a high solidification rate is used when melting

With the development of the machine industry, the mixture is suitable for parts of various equipment, and is used for laying out high-voltage lines.

6% alloys with small amounts of nickel and copper are used for bearings. It is tin that provides sliding in these joints, and the products themselves become unique among others.

Thanks to tin in the alloy itself, aluminum's resistance to corrosion improves, especially when combined with copper.

The alloy is very advantageous because it is strong, light, economical and easy to process at low temperatures. It easily conducts heat and electricity, which makes it possible to use it in construction. The compound is also highly reflective.

Despite its positive qualities, the aluminum-tin alloy has a low linear expansion coefficient.

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What is silumin

Silumin is a metal alloy made from aluminum. In general, various aluminum alloys are widely used in industry, just like alloys containing lead.

The formula of silumin is quite simple, the main components are aluminum and silicon, depending on the type of silumin, the silicon content in percent can be from 10 to 20. Moreover, alloys with the addition of silicon are more durable than aluminum with a lead additive.

Soldering aluminum with tin

Aluminum is often found in the manufacture of cookware, in electrical wiring, casings of various products and other places. To solder aluminum I use different types of solders. One of the most common is tin, since it is the easiest to find, and its properties are quite suitable for obtaining a high-quality compound. Soldering of aluminum with tin involves the use of fluxes and can be carried out both in the workplace and at home. The solder itself often contains some additives, such as zinc, which promotes better soldering and spreading of the filler material.

Tin is a low-melting solder, which is great for working with aluminum because its melting point is relatively low. If you use hard-melting solders, then with strong heating, aluminum may lose its qualities, or even melt before the filler material itself. Several soldering methods can be used here, and are equally effective.

Alloy composition

Depending on the type, silumin has a different composition. The most common types are:

• an alloy of aluminum with silicon, with silicon containing about 10%;
• the second type of silumin has higher strength. The alloy composition contains about 20% silicon;

In addition, other aluminum alloys are often used in industry:

• an alloy of aluminum with magnesium and silicon, often used for the manufacture of automobile bodies;
• an alloy of aluminum and tin, used in the production of cast bearings;
• aluminum-magnesium alloys are used in aggressive environments, for example, in the exterior decoration of buildings.

Advantages

• Soldering aluminum with tin is relatively inexpensive, since the cost of solder is low;
• The material is universal and suitable for working with both thick and thin workpieces;
• Solder melts well when exposed to temperature and spreads well over the surface, forming a high-quality connection, penetrating into all small cracks and recesses;
• Due to the low melting point, the process is relatively fast;
• The material is always available for sale and there are no problems with its search and selection.

Flaws

• After completion of the process, the finished product will have a lower melting point at the soldering site;
• The strength of the connection is not designed for high mechanical loads;
• Soldering aluminum with tin at home does not provide such a high-quality connection as other connection methods and can be used mainly for minor repairs of products with little responsibility during operation.

Nuances when soldering

The main feature when soldering aluminum is the fight against oxide film. It has become the biggest problem that needs to be solved even before the soldering process using cleaning, solvents and other methods. Soldering aluminum with hard solders requires strict adherence to the modes, since too high a temperature can ruin the metal itself, and too low a temperature will not allow you to make a high-quality connection. When working with large thicknesses of metal, soldering is carried out in several layers.

Aluminum alloys

Details Category:

ALUMINUM ALLOYS

. Alloys m.b. are called aluminum if the weight content of Al in them exceeds 50%. The concept of “light alloys” refers to alloys with a specific gravity of up to 3 and includes, in addition to aluminum alloys, magnesium alloys; but the vast majority of aluminum alloys are classified as “light alloys” and constitute their main part. Binary alloys of Al with other elements have now been studied most fully. In terms of the number of phase diagrams of binary alloys studied, aluminum alloys are in second place, copper alloys are in fourth place, and iron alloys are in seventh place. Aluminum alloys with Mg, Be, Sn, Si, C, B, Ca, Ge and In can be used at very different ratios of their composition. Aluminum alloys with low-melting metals Zn, Sb and with the middle group of high-melting metals: Cu (Fig. 1), Ni, Ag, Au, Fe, Co, Pt and Mn, as well as with high-melting metals, such as Cr, Mo, are used , W, V, etc., with light earth-alkaline metals, earth metals proper and with a number of low-melting metalloids. But these alloys are used with a strictly limited amount of impurities, since the excess of the latter makes aluminum alloys brittle or produces chemically unstable compounds. And only with alkali metals, other low-melting metals and metalloids of the seventh group, double aluminum alloys are not used.

Of the ternary aluminum alloys, the systems Al-Cu-Mg (Vogel), Al-Cu-Sn (Edwards a. Andrew), Al-Cu-Zn (Carpenter, Edwards, Schulz, Jares), Al-Mg-Zn (Eger) have been studied. , partially Al-Cu-Ni (Haughton), etc. Of the quaternary aluminum alloys, the Al-Cu-Ni-Mg system with a constant Mg content = 1% (Bingham) has been partially studied.

The practice of manufacturing aluminum alloys in terms of the number of alloyed elements has gone far beyond the scope of the studied state diagrams. The technical application of aluminum alloys is currently so widespread that below, in the listing of individual aluminum alloys, only the alloys that are of greatest importance in industry are given. Every year, aluminum alloys are gaining more and more new areas of application and in some cases are already seriously competing with iron alloys due to their high mechanical properties and low specific gravity. The production of aluminum alloys is basically like this. As the starting metal for smelting, aluminum is used in ingots of varying purity, depending on the composition and purpose of the aluminum alloys: for more critical aluminum alloys, aluminum should be used. purity not lower than 98% and even 99%. Copper, predominantly electrolytic, is used first for the production of a low-melting alloy, and then, in the form of an alloy, for the production of the corresponding aluminum alloy. The following alloys are known: 33% Cu + 67% Al, 50% Cu + 50% Al and 60% Cu + 40% Al. Most foundries use a second alloy, composed by adding liquid copper to liquid aluminum. Manganese with a possibly low iron content (if the latter is not included as a necessary component of a given aluminum alloy) is also used in the form of an alloy. Alloys used are: 4% Mn + 96% Al, 8-10% Mn + rest. Al and 25% Mn+75% Al. The latter has the greatest application and is formed by adding solid aluminum to liquid manganese. If aluminum alloys must contain both Cu and Mn at the same time, then a triple alloy is used: 50-55% Cu + 10-8% Mn + 40-37% Al. Magnesium, 99-99.5% pure, is added before casting. It is not recommended to use Mg in the form of alloys due to oxide inclusions. When preparing a charge for melting aluminum alloys, especially those going into rolling, use only pure metals whenever possible and are especially wary of thin scraps and shavings that carry a lot of Al2O3 and other contaminants. Despite many years of practice in the manufacture of aluminum alloys, there are still no firmly established melting methods. Heating occurs either in coke and oil furnaces, or in furnaces. The types of furnaces used for melting aluminum alloys are varied in design, in the nature of heating, and in fuel. The furnace atmosphere is preferably reducing.

Crucible melting is most applicable in both graphite-clay and cast iron crucibles (especially cast iron allitized according to the Krupp patent). The main method for aluminum alloys is an open flame furnace, Rockwell type, gas or oil. In recent years, due to waste, low efficiency and inaccurate temperature control in combustion furnaces, the production of aluminum alloys has been decisively switched to electric smelting. For aluminum alloys, electric furnaces with voltaic arc heating (indirect action) and resistance furnaces are used. The former are convenient in terms of speed of melting, thorough mixing of the alloy and uniform heating of the lining (for example, the “Booth” furnace and the “Detroit” furnace; the latter are drum-type, in which local overheating is eliminated by rotating the furnace frame). The second, resistance furnaces, are convenient in terms of temperature control, but worse in terms of metal mixing and higher energy consumption (for example, “Baily” or “General-Electric-Ofen” furnaces). The lower the casting temperature and the faster the cooling of the metal, the finer the crystallites of the structure and the higher the mechanical qualities. If in aluminum alloys the phenomenon of reverse segregation occurs, which is enhanced by this casting method, then the fine crystallinity of the casting should be partly sacrificed in order to avoid this phenomenon. For casting aluminum alloys, casting is used both in sand and in a chill mold. For aluminum alloys used for rolling, casting into metal molds is mainly used. Primary crystallites of chemical compounds (for example, FeAl3 or CuAl2) must be crushed by rolling. Hot rolling mills d. b. very precise in design, since their work program is close to the work program on cold rolling mills. Heating of plates before rolling in large productions of aluminum alloys is carried out in methodical furnaces with the movement of plates along the hearth by a special pusher. For small charges (~1 t), muffle furnaces are used. Starting from approximately 3 mm thickness, thinner sheets are produced by cold rolling (Fig. 2).

Annealing of aluminum alloys during rolling d.b. selected in temperature and duration not only depending on the composition of the aluminum alloys, but also on the magnitude of the last deformation, in order to avoid extreme crystallite growth during recrystallization. For critical aluminum alloys, instead of ordinary flame furnaces, salt baths are often used for annealing (for example, 50-75% potassium nitrate + 50-25% sodium nitrate, etc.), allowing precise temperature control and guaranteeing uniform annealing. Heat treatment after rolling depends on the composition of the aluminum alloy. The production of aluminum alloys in the USSR is carried out by: State Kolchuginsky, State Aviation Plant No. 1, a new large plant near Moscow on the Lenin Hills and a number of engine-building, mainly aviation, factories.

Of the double aluminum alloys, used in very different ways, the most widely used are aluminum alloys with magnesium and silicon.

Aluminum alloys with magnesium (Fig. 3).

Under the brands “3 S” they use an alloy with 1.25% Mg, “Aero” - with 2.5% Mg, “T-metal” - with 3.8% Mg. But an aluminum alloy with 5-10% Mg, called Magnalium, is more widely used. Specific gravity 2.40-2.57. With a small Mg content, it is hot forged and rolled. It is well processed with a cutting tool and polished. It is used for optical mirrors, not inferior in reflectivity to glass mirrors and superior to them in their ability to reflect ultraviolet rays. Used for bearings of rapidly rotating shafts. Galvanically durablely coated with gold, silver, nickel. Resists the action of ammonia fumes, cold concentrated sulfuric acid, stearic and acetic acids. Melts at 630-575°C in graphite or cast iron crucibles coated on the inside with a layer of clay. When casting in sand, temporary tensile strength Zmax = 14-18 kg/mm2, elongation i= 1%, when casting in a chill mold i= 5%, Brinell hardness HBr. = 63. The best casting temperature is 670-700°C. Rolled - Zmax= 40 kg/mm2, i = 12%. “Magnalium X” contains 2% Cu + 2% Mg + 1% Ni, and is used in electrical products and in the production of automobiles. “Magnalium Z” (1.5% Mg + 3% Sn) - for extrusion. Also called “Magnalium” are aluminum alloys: 0.2% Cu + 1.6% Mg + 3% Sn + 0.7% Pb and 1.7% Cu + 1% Mg + 3% Sn + 0.7% Bi. More complex aluminum alloys with Mg and with small additives of Si and others, forming solid solutions with Al, not exceeding 1-1.5% in total, are known under the name “Aludur” (0.5% Mg + 0.5% Si ; 0.8% Mg + 0.7% Si). Heat treatment: hardening and “aging” at 160°C. “Aludurs” allow stamping, rolling, drawing, chill casting and sand casting.

Well sharpened, drilled and milled. They have good conductivity. Brand “533 D” - for overhead electrical wiring: the strength is 40% higher than Al, the conductivity is only 3-4% lower. The antenna of the Nauen radio station with a span of 500 m is made of this alloy. High-frequency current voltage can reach 60,000-200,000 V. Brand “570 V” - semi-solid and “570 E” - springy-hard; dangerous effects of alkalis, carbonates, inorganic acids, with the exception of HNO3; limited stability in seawater. American alloy “51 S” (1.5% Mg + 1% Si) m.b. classified according to mechanical qualities as “Aludurs”. Other magnesium aluminum alloys include the following alloys: for dental fillings (1% Mg + 0.1% Na + 0.05% Sn); resisting the influence of the atmosphere, sea water and acid solutions (3.5-4.5% Mg + 1-1.4% Sn + 0.1-0.15% P) and increased strength (7% Mg + 7% Cu + 0.4% Sn + 0.14% P).

Aluminum alloys with beryllium have not yet found widespread use. With increasing Be content, aluminum alloys become stronger and harder. Binary Al-Be and ternary Al-Be-Mg alloys age significantly after heat treatment at room temperature. Aluminum alloys 4.5% Cu + 0.6% Be + 0.6% Mg + 0.1% Si after hardening from 520°C, aging at room temperature, increases the Brinell hardness from 76 to 108.

Aluminum alloys with tin. Aluminum alloys with 3% Sn are used for ornaments. In 1884, an aluminum alloy with 9-16% Sn was used for shells, and 23% Sn + 2% Cu for type. Aluminum alloys 10-11-15% Sn + 3-1-2% Ni are processed with a file and soldered. For crankcases, motors and stressed parts, aluminum alloy 10% Sn + 3.5% Cu + 1% Ni is used. Aluminum alloys with 10% Sn with additives 2% W and 5% Cu + 10% Sb are known - for machining by cutting; as a well-polished aluminum alloy - 10% Sn + 6% Cu + 0.17% Sb + 0.05% Mg.

Aluminum alloys with silicon (Fig. 4), from 5 to 20%, and Ch. arr. with 10-14% Si, known as “Silumin”.

The alloy with 10% Si has a specific gravity of 2.55, a melting point of 595-578°C, and a heat capacity of 0.386.

The best casting temperature is 650-680°C. “Silumin” with 13% Si when cast under pressure has Zmax = 19.6–21 kg/mm2, i = 1–3%, HBr.500 = 70–80. For rolling, it is better with a lower Si content. The alloy is used as a structural material and especially in machine parts operating at elevated temperatures; is more resistant to sulfuric acid corrosion than other commonly used cast aluminum alloys; “Silumin” with a small content (up to 2%) of various additives is known in America under the name “Alpax”. "Sulumin" with 4.5-6.5% Si is called "S. A.E. No. 35.” Aluminum alloys with Si and Cu additives such that the Al content = 93% are known under the name Lautal. Its manufacture requires great care. Specific gravity 2.74, electrical conductivity 40% of pure copper and 70% of pure aluminum. The alloy is well processed, forged, rolled, drawn, stamped. When flanging, the radius of curvature should be. not less than the wall thickness of the part. Forging is best at 450-480°C. Forgings must be subjected to heat treatment. Does not age at room temperature. Heat treatment is as follows: by hardening, Zmax can be reduced to 23 kg/mm2 (Fig. 5); exposure at 16 hours. at 120°C after hardening at 480–500°C, it increases the mechanical qualities to normal (normal are those that are always restored with correctly carried out heat treatments), while the elongation remains 18–23%.

The compositions of Lautal are known: 2% Cu + 1% Si; 3% Cu + 3% Si.

The following alloys are used for injection molding:

Alloy used for casting: 6% Si + 4% Cu. Specific gravity 2.69; linear expansion coefficient 23.2∙10-6. Melting point 630-590°C. The most favorable casting temperature is 680-720°C. Sand casting hardness is 58 Brinell, 13 Shore.

Cast aluminum alloy - 3.5% Cu + 4% Si - has Zmax = 13.3 kg/mm2, I = 1.4%, proportionality limit Zр = 3.7 kg/mm2.

Of the double aluminum alloys containing impurities within limited limits, the most widely used are aluminum alloys with zinc, copper, nickel and manganese.

Aluminum alloys with zinc (Fig. 6) cast well, do not oxidize in air, but are destroyed by water.

German “Al-7” - with 10% Zn and “Al-20” - with 17% Zn. The latter has a specific gravity of 2.93 when cast in sand. The coefficient of linear expansion is 26.0∙10-6, the melting point is 630–575°C.

"Tsiskon" - aluminum alloy with 25% Zn, "British 2:1" - with 33.4% Zn, specific gravity 3.65, melting point 600-510 ° C; The best casting temperature is 640-670°C. "Alzen" is an aluminum alloy similar to "British 2:1". There are a number of commonly used aluminum alloys with zinc containing Cu additive. German, for injection moldings: 14% Zn + 4.5% Cu - for the bases of meters and other measuring instruments, 10% Zn + 2% Cu - for the housings of various devices and apparatus, for small parts of various mechanisms and machines. The latter alloy is widely used in England for a wide variety of purposes. Aluminum alloy “No. 31”, or “German alloy” (12-15% Zn + 3-4% Cu), has the following qualities: coefficient of linear expansion 18.4∙10-6, melting point 645-600°C; cast at 700°C in sand: Zmax = 16.2 kg/mm2, i= 2.5%. The best temperature for casting is 700-730°C. Similar to this aluminum alloy, in England there is an aluminum alloy (13% Zn + 3-4% Cu) under the brand name “L-5”. “British A” (20% Zn + 3% Cu) is intended for parts operating at elevated temperatures; melting point 625–560°C, sand casting has Zmax = 28 kg/mm2, i ≈ 0%. The best temperature for casting is 675-710°C. The rods drawn from it were used after annealing at 250°C for rivets. Similar to him is the so-called. "Aluminite" (23% Zn + 3% Cu). Aluminum alloy for casting “Aero” (28% Zn + 4% Cu) when casting in sand has Zmax = 17 kg/mm2, i = 1%. For aircraft engines, alloys are used, the composition of which is given in the following table:

Aluminum alloys for zinc casting with iron additives are known as non-porous; Iron additives in various grades are listed in the following table:

Aluminum alloys 1.5–15% Zn + 0.5–7% Sn are used in the production of hydrogen. Of the more complex ones, “Skleron” is known (12% Zn + 3% Cu + 1% Mn + 1% Ni + 5% Si or instead of Ni - 0.08% Li), specific gravity 3; mechanical qualities after “aging”: Zmax = 48.5 kg/mm2; yield strength = 38 kg/mm2; i = 11%; lateral compression q = 15%; modulus of elasticity E = 7220 kg/mm2. It is well processed with a cutting tool, polished, pressed. Used as a construction material. In relation to sea water it is similar to aluminum. Aluminum alloy "Mak Adam" (12-18% Zn + 3% Cu + 0.2% Mg) has Zp = 12 kg/mm2, Zmax = 21-22 kg/mm2. Under the brand name "Al. Cast. С°" the alloy 7-8% Zn + 3% Cu + 1-1.3% Fe + 0.2% Mg is known. For injection molding of parts of various devices, aluminum alloy 15% Zn + 2.5% Cu + 2.5% Sn is used.

Aluminum alloy “British E”: 20% Zn + 2.3% Cu + 0.5% Mn + 0.5% Mg and “British G”: 18% Zn + 2.5% Cu + 0.35% Mn + 0.35% Mg - both for structures, mechanical qualities are similar to duralumin. As moisture-resistant and suitable for tools - aluminum alloy: 1.9% Zn + 1.9% Sn + 1.4% Pb + 0.5% Mg + 0.2% P. For parts subjected to stress at elevated temperatures, use aluminum alloy: 7.5% Zn + 3.5% Cu + 0.5% Ni + 0.5% Sn.

Aluminum alloys with antimony are used to make feathers, after forging Zmax = 39 kg/mm2, called “Tungsten”: 1.44% Sb + 0.38% Cu + 0.1% Sn + 0.04% W.

Aluminum alloys with copper (Figs. 7 and 8): with 4% Cu is rolled and is sometimes called “European solid aluminum”; in cold-worked form it has Zmax = 35 kg/mm2, i = 2%.

Heat treatment consists of hardening and “forced aging”. Aluminum alloy with 8% Cu is called “American No. 12” and is extremely widely used (in the USSR at most aircraft engine factories). In the form of sand and chill castings, it is used for aircraft engine parts such as crankcases, cylinder heads, camshaft housings, oil and water pump housings, carburetors, gear housings, etc.

In the form of injection moldings - for parts of valves, magnetos, incendiary batteries, lighting installations, speed meters, phonographs, autoclaves, counting, knitting, writing, etc. machines. The specific gravity of this aluminum alloy is ~3; melting point 621°C; linear expansion coefficient from 23.1∙10-6 to 24.6∙10-6. The best temperature for casting is 660-690°C. Aluminum alloy with 9-12% Cu is used for engine pistons. “American alloy for pistons” is an aluminum alloy with 9-11% Cu, with a melting point of 630-540 ° C; the best casting temperature is 680-720°C; "British L-8" - with 12% Cu. “German normal piston alloy” refers to an aluminum alloy with 15% Cu. With Mg additives, an aluminum alloy of 2.5-3.5% Cu + 0.5% Mg, called “Montanium”, was used for parts of airships. The Alferium aluminum alloy also consists of Cu and Mg additives; in terms of its mechanical qualities, thermal and mechanical processing, it is no different from duralumin and serves the same purposes as the latter. “Linit 146”: 8.5% Cu + 0.2% Mg + 1.2% Fe, gives Zmax = 18.2 kg/mm2; Zp = 4.2 kg/mm2; i= 0.5%. “Linit 195”: 4.6% Cu + 0.1% Mg + 0.6% Fe, gives Zmax = 21.8 kg/mm2; Zp = 6 kg/mm2; i= 2.5%; aluminum alloys with Mn additive are known to have the following composition:

For rivets, the American Air Force used an aluminum alloy of the following composition:

Under the name "Navy" the American Navy uses an aluminum alloy: 2% Cu + 1% Mn, with a specific gravity of 2.85; melting temperature 650-640°C, best casting temperature 700-730°C, sand casting Zmax = 14.7 kg/mm2; i = 7%. Aluminum alloy “Navi N”: 6% Cu + 3% Mn, gives Zmax = 12.7 kg/mm2; i= 8%. “British 14:1”: ​​14% Cu + 1% Mn, has a melting point of 620-548°C, the best temperature for casting is 670-700°C. Aluminum alloy "Mak Lure": 8% Cu + 0.2% Mg + 0.9% Fe, has Zmax = 13.5 kg/mm2, i = 3%. Aluminum alloy with zinc additive “Maluminium”: 6.5% Cu + 5% Zn + 1.4% Fe, has Zmax = 12 kg/mm2; Zp = 9 kg/mm2; i= 1.5%.

Mainly aluminum alloys, in addition to Cu with a Zn additive, are used for pressure castings; They are much lighter than zinc alloys, but they are more difficult to work with. These include: 12% Cu + 1.6% Zn and 14% Cu + 3.5% Zn + 0.7% Fe; the latter in injection moldings has Zmax = 17.7 kg/mm2, i= 3%. More complex aluminum alloys with Cu as the main additive are the following: the most common “Duralumin” and similar aluminum alloys; “Argilite”: 6% Cu + 2% Si + 2% Bi, low-corrosive; French: 1.5-4% Cu+ 0.25-1.25% Mn+ 0.25-1.25% Ag, drawn, rolled, forged, engraved, used to replace brass and iron; aluminum alloy 3.7% Cu + 2.8% Ni + 1.2% Mn - has hardness and lightness, used for automobile pumps and wheel covers; “Asieral”: 6.4% Cu + 0.4% Zn + 0.9% Ni, when cast in sand it has Zmax = 15.5 kg/mm2; Zp = 4.2 kg/mm2; i= 2%; its French version is 2.3-3.8% Cu + 0.2-0.5% Mg + 1-1.5% Mn + 1.5% Fe. Aluminum alloy is used under the “17 S” brand: 3-5% Cu + 0.7% Mg + 1% Mn, and under the “25 8” brand: 3-5% Cu + 1-2% Mn + 1% Si. Both of these American alloys in mechanical qualities and heat treatment are almost no different from duralumin, just like the rolled aluminum alloy “Y-alloy” (English): 4% Cu + 2% Ni + 1.5% Mg + 0, 5% Si, but the latter is also used in the form of castings. Depending on the casting temperature, these alloys have the following mechanical properties:

When the temperature rises to 300°C, its mechanical qualities decrease slightly: Zmax = 13.8 kg/mm2 (a comparative diagram of mechanical qualities is given in Fig. 9), Brinell hardness when casting in a chill mold is 53, when casting in sand 46; specific gravity of the alloy 2.80; melting point 650-640°C.

Under the brand name “B-4” in England, an alloy of 7% Cu + 1% Sn + 1% Zn was used for flying machines. Of the bearing aluminum alloys used: 7.5% Cu + 0.25% Sn, 5.8% Cu+ 1.6% Sn, 3% Cu+ 1% Sn, 5-50% Sn + 5-30% Sb, replacing in the latter Sb or Co, or Cr, or Fe, or Mn, or Ni. The bobbins for the fabrication of artificial silk are made of aluminum alloy: 7.5% Cu + 4.5% Ni + 0.15% Mg. For parts operating at high temperatures, Magnalite was recommended: 4% Cu + 1.5% Ni + 1.5% Mg + 0.6% Fe. Called “Partinium” - aluminum alloy 3-7.5% Cu + 0.75-1.9% Sn + 0.04-0.1% W + 0.12-0.29% Sb and the second - with replacement W through 0.16-0.40% Mg without Sb. Called “Verilit” - aluminum alloy 2.5% Cu + 0.3% Mn + 0.7% Fe: Zmax = 11.2 kg/mm2; i= 4%.

Aluminum alloys with nickel (Fig. 10) have less corrosion than Al-Cu alloys. Well cast: 10% Ni + 5% Zn, used in the production of precision machines and instruments. Resistant against sulfuric acid: 5% Ni + 2% Bi + 1% Si.

Aluminum alloys with silver: “Argental” with 3% Ag is used in jewelry for precision scales and for physical instruments; resists the influence of atmosphere, alkalis and nitric acid; easy to process and melt. For engraving: 6-9% Ag + 1% Cu.

Aluminum alloys with gold are used mainly as solders: 18.5% Au + 3.7% Ag + 3.7% Cu, 19.3% Au + 13.3 Cu + 0.7% Pt, 19.8% Au + 13.3% Ag + 0.7% Pt.

Aluminum alloys with iron: coin alloy with 2% Fe and used as filler alloys in metallurgy: 7-10-14% Fe + 3-5-6% Si.

Aluminum alloys with cobalt have technical properties similar to Al-Ni. With increasing Co addition, casting shrinkage decreases and disappears at 8% Co. Aluminum alloys 8-10% Co + 0.8-1.2% W are used: rich Co - for foundry purposes, poor Co - for forging and rolling.

Aluminum alloys with manganese are known to resist seawater corrosion. The complex anti-corrosion alloy is branded “KS-Zaewasser”: 3% Mn + 2.5% Mg + 0.5% Sb. Melted in graphite crucibles; Overheating above 780°C should be avoided. The best casting temperature is 700°C. Works well with cutting tools. Non-porous casting. In sea water, contact with bronze is undesirable. Used on fittings, dishes and parts in contact with sea water. Specific gravity 2.8.

Aluminum alloys with platinum are sometimes used instead of pure Pt.

Aluminum alloys with semi-brittle high-melting metals: Cr, Mo, W, V, Ta, Ti and Zr are rarely used. Due to its sonority and lightness, aluminum alloy with 2% V is suitable for musical instruments.

Bearing axle boxes for locomotives are made from complex aluminum alloys with lead: 0-20% Pb + 10% Sn + 10% Sb. A complex aluminum alloy with bismuth 5% Bi + 2.5% Ni + 2.5% Fe resists strong oxidizing agents, is electrically conductive and easily solderable. Complex aluminum alloys with cadmium called “Solbiski alloys”: 2.5% Cd + 0.5% Sn + 0.5% Ni, 3% Cd + 1% Sn + 1% Ni and 3% Cd + 1% Ni + 1% Zn was used for machine parts, rolled, well processed. Data on the aluminum alloys Montegel, Constructal 2 and Constructal 8 have not yet been published in sufficient detail.

Source: Martens. Technical encyclopedia. Volume 1 - 1927

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Soldering aluminum with regular tin

If you don’t have argon arc welding or special electrodes at hand, but you need to solder aluminum, then you can get by with just tin. Aluminum products are the most affordable and widespread, so you often have to repair them yourself.

And although aluminum is easy to machine, it is not easy to solder. The main problem that arises when soldering aluminum is the oxide film on its surface. Heated aluminum cools quickly, which instantly leads to the formation of oxides.

Therefore, in most cases, active mercury fluxes and replaceable soldering iron tips are used for soldering aluminum products. However, if you try, you can solder aluminum with ordinary tin, using a gas burner, rosin and a soldering iron.

Soldering aluminum with regular tin and rosin

After the surfaces of aluminum products are treated with stone, a thin layer of heated rosin is applied to them. You can use ready-made liquid rosin, or you can melt pine rosin using a soldering iron or gas burner.

Further, the process of soldering aluminum is not much different from soldering copper or other non-ferrous metals. To do this, take a soldering iron and apply heated tin to the place where the parts are soldered. You can heat the tin with a torch and then rub it into the aluminum with a soldering iron tip.

Even liquid tin, due to the characteristics of aluminum, will not spread on the surface of the part. Therefore, we take a soldering iron and carefully rub the tin into the joint. In this case, as mentioned above, due to the presence of dust on the surface of aluminum, the oxide film is destroyed.

After soldering, let the parts cool and check the connection for strength. And, as practice shows, the soldered connection of aluminum products thus turns out to be much stronger than those made of copper.

All this is explained by the fact that the melting point of copper is much higher than that of aluminum. Aluminum also has a greater ability to diffuse with other metals.

This is the simplest and most affordable way to connect two aluminum parts or “patch” a hole. It does not require any special tools or welding. It is quite possible that the method will be quite suitable for soldering parts made of other non-ferrous metals.

Source

The difference between silumin and other metals and alloys

To understand what is in front of you, silumin or steel, just remember and pay attention to a few simple things:

• color, silumin is distinguished by a gray surface color and a silvery color on the cut. Remembering this, you can easily distinguish it from copper, bronze or brass. The surface of these metals has a yellow or reddish tint;
• magnetic properties, silumin, unlike steel, is not magnetic;
• weight, silumin has less weight than similar steel products.

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Soldering aluminum with tin: methods and rules

Aluminum is a common material used to create wires, cookware, and more. Due to its characteristics, aluminum can deteriorate over time or other influences, which necessitates repair work. The best option in this case is soldering, which can be done in various ways and using different elements. The most convenient way is to use tin for soldering aluminum.

Peculiarities

Aluminum is a metal that has sufficient density, but is also lightweight. It is these advantages that have made it possible to use this material so widely for the manufacture of tableware. The process of using aluminum products is not complicated, but from time to time situations arise when it is necessary to eliminate a crack, hole, or solder parts of the cookware. In addition to kitchen utensils, aluminum is used to make wire, which is convenient to work with due to its softness but good strength.

There is only one drawback to this wire - it is very difficult to solder.

Most metals can be heated and soldered, but aluminum is a special substance that oxidizes when exposed to air and becomes coated with an oxide film that no metal can sit on top of. To solder this material, you need to select a suitable flux.

Flux is a substance or several components that can be used to remove oxides from metals that need to be soldered. Thanks to the organic and inorganic compounds of fluxes, it will be possible to remove surface tension and improve the spreading of liquid solder. In addition, it allows you to protect the material from environmental influences.

Since aluminum is an unusual metal, it is worth looking for a special flux for it. Soldering aluminum with tin is considered the simplest and most convenient option in which you can get the desired result. The advantages of using tin for aluminum smelting include:

• low price of the material;
• the ability to use tin for parts with different thicknesses;
• high melting rate and the ability to cover the entire surface of the aluminum part on which work is being carried out;
• low melting point, which allows you to quickly cope with the task;
• general availability of tin.

Properties of silumin

Silumin has properties that have made it a very popular material on the modern market. It is quite durable and reliable, and the low cost and ease of manufacturing complex elements often make this material irreplaceable. Let's take a closer look at its properties.

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Chemical properties

Silumin alloy is similar in its chemical properties to pure aluminum, it all depends only on the amount of impurities. For example, unlike duralumin, silumin is not susceptible to corrosion in conditions of high humidity, including sea water.

Physical properties

In terms of its physical properties, silumin is often compared to stainless steel, but at the same time it is much lighter. The alloy has the following physical properties:

• the strength of the material is not much inferior to its steel counterparts. It becomes possible to achieve a ratio of low weight and high strength with a lower density of the alloy compared to steel;
• in appearance, silumin is very similar to pure aluminum, the color of the products is gray, and in cross-section - silver;
• the material has high fluidity, which makes it possible to manufacture products of complex shapes from it;
• the melting point of silumin is relatively low, about 700 °C;
• Along with excellent strength, silumin has high fragility;
• silumin is not magnetic.

Mechanical properties

Mechanical properties directly depend on the chemical composition of the alloy and its manufacturing process. The main mechanical characteristics of silumin can be considered:

• fragility, the material may crumble during processing;
• high density;
• low microhardness.

Foundry properties

Aluminum-silicon alloys are excellent for making cast products. At the same time, the material has high specific strength, low weight and resistance to corrosion. An additional advantage is the low cost of the finished product.

Despite the obvious advantages, silumin also has a drawback - increased gas porosity, however, modern technological processes make it possible to eliminate this feature during the casting process.

Methods

In the process of melting aluminum with tin, an oxide film appears, which can only be removed with the help of solvents or metal brushes. To properly melt the base metal, you need to choose the right temperature. At high rates, aluminum will be destroyed, at low rates, it will not be possible to successfully solder the materials.

There are several methods of tin soldering.

1. Using a gas burner, which is attached with a hose to the cylinder, which makes it possible to adjust the power of the incoming gas. The fire temperature can be adjusted by changing the pressure inside the cylinder.
2. Using gasoline burners. It is used for joining thin layers of metal due to the impossibility of changing and increasing the flame temperature.
3. Using a soldering iron. For work, additional materials are required, such as rosin. The soldering iron needs to be heated to a temperature that melts both rosin and tin.

For such work, it is necessary to use flux for aluminum F-59A, F-61A and active flux for soldering aluminum. When melting metal, you need to have the following tools with you:

• solvent;
• metal brush;
• soldering iron or torch;
• cutting tool;
• flux.

Once you have everything you need, you can get to work.