Silicon aluminum alloy

Soft magnetic materials are characterized by high permeabiUty and low coercivity. There are sis principal groups of commercially important soft magnetic materials iron and low carbon steels, iron—siUcon alloys, iron—aluminum and iron—aluminum—silicon alloys, nickel—iron alloys, iron-cobalt alloys, and ferrites. In addition, iron-boron-based amorphous soft magnetic alloys are commercially available. Some have properties similar to the best grades of the permalloys whereas others exhibit core losses substantially below those of the oriented siUcon steels. Table 1 summarizes the properties of some of these materials. 

Iron—Aluminum and Iron—Aluminum—Silicon Alloys. The influence of aluminum on the physical and magnetic properties of iron is similar to that of silicon, ie, stabilization of the bcc phase, increased resistivity, decreased ductility, and decreased saturation magnetization, magnetocrystalline anisotropy, and magnetostriction. Whereas Si—Ee alloys are well estabHshed for electrical appHcations, the aluminum—iron alloys have not been studied commercially. However, small (up to ca 0.3%) amounts of A1 have been added to the nonoriented grades of siHcon steel, because the decrease in ductiHty is less with A1 than with Si. 

Sodium does not form alloys with aluminum but is used to modify the grain stmcture of aluminum—silicon alloys and aluminum—copper alloys for improved machinabiUty. Sodium—gold alloy is photoelectricaHy sensitive and may be used ia photoelectric cells. A sodium—2iac alloy, containing 2 wt % sodium and 98 wt % 2iac, is used to deoxidi2e other metals. 

Four types of substrates were examined in this study. Cold rolled steel (CRS), galvanized steel (ZGUS), and an aluminum-silicon alloy coated steel (Al-Tl) represented bare and metallic coated steels. 

Consider an aluminum-rich binary aluminum-silicon alloy. The melting temperature of aluminum is 660 °C, and the eutectic is at 577 °C and 12.6 wt% Si. The maximum solubility of silicon in aluminum is 1.65% Si at 577 °C. The liquidus and solidus can be approximated by straight lines. The difflisivity of silicon in liquid aluminum is 8 x 10-8 m2/s. Freezing occurs at a rate of 10 pm/s. 

Cast iron having very high resistance to acids is marketed in the form of an alloy containing 12 per cent of silicon and 4 to 6 per cent of aluminum. These ferro-aluminum-silicon alloys are attacked readily only by hydrochloric acid, the most corrosive acid. They were first used in England under the names Ironac and Tantiron. Kieselguss, Acidur, and Clusiron are imitations which are all easily cast, but which are very hard and brittle so that they have to be worked on an emery wheel. These alloys are exceptionally well suited for nitric acid... 

Fig. 13 Extent of wear damage on (a) uncoated and (b) nanocrystalline diamond coated tool inserts after machining of hypereutectic aluminum-silicon alloy.

The plate ozonizers consist of four groups each with six pairs of hollow Alpax (an aluminum-silicon alloy) plates through which cooling water circulates. A pair of glass dielectrics is placed between each pair of plates. The maximum power input is 1.5 kw. per cell. 

Brisley, R.J. and Fray, D.J. (1983) Determination of the sodium activity in aluminum and aluminum silicon alloys using sodium beta alumina. Metall. Trans. 

U.S. production reactors consisted of a uranium metal slug bonded with aluminum-silicon alloy to an aluminum can. Because of the bond, mechanical decladding was impractical. Chemical decladding consisted in dissolving the aluminum can and the bond in hot, aqueous, 10 w/o sodium hydroxide solution containing about 20 w/o sodium nitrate to prevent evolution of hydrogen. The overall reaction was [B12]... 

Materials Scientist Materials scientists synthesize new materials and analyze their properties. They work in national laboratories, in industry, and in academia. For example, scientists at NASA have developed new aluminum-silicon alloys that can be employed to build lighter and stronger engines. To learn more about chemistry careers, visit glencoe.com. 

Z.Y. Ma, S.R. Sharma, and R.S. Mishra, Effect of Multiple-Pass Friction Stir Processing on Microstructure and Tensile Properties of a Cast Aluminum-Silicon Alloy, Scr. Mater., Vol 54 (No. 9), May 2006, p 1623-1626... 

Production of silicon is historically a young industry. Most products made out of this element are linked to modem society and the needs that have developed since 1950s. Aluminum-silicon alloys are today the most important automotive alloys computers would not have reached today s level of capacity without silicon chips, and our personal welfare in daily life is heavily influenced by silicone-based products. 

Sustainable products should make a positive contribution to the overall ecological resource problem. Many products made out of silicon obviously fall into this category, such as solar silicon and aluminum-silicon alloys, while others contribute to sustainability more indirectly and maybe in a long-term perspective. 

In 1980 a standard middle-class automobile contained approx. 60 kg of aluminum. Since then, environmental forces, energy prices and technology developments have raised the use of aluminum to approx. 100 kg per vehicle and the automobile production has almost doubled. Aluminum-silicon alloys make up more than 70 % of the aluminum alloys in a car and contain on average 7 % silicon. Silicon contributes to alloy castability and strength and to weight reduction. In addition, aluminum-silicon alloys are fully recyclable. Without the development of silicon-containing aluminum alloys, recycling of aluminum from automobiles would have been far more complicated, since these alloys are able to consume impurity elements better than all other alumimun alloys and are still valuable in new products. 

Aluminum-silicon alloys are important for energy saving and recycling of aluminum alloys. 

Table 2.61 Uniaxial Tensile Data for Aluminum-Silicon Alloy-Thornel-50 Composite Thermally Cycled 20 Times from -193 to -i-500°C (5)...

Aluminum coatings are produced as type 1 coating, a thin (20-25 jim) aluminum-silicon alloy coating, and type 2, a thicker (30-50 p,m) pure... 

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