Alloys with silicon

A major use of germanium is as an alloy with silicon.P l a SiGe transistor with speed of over 60 GHz can allow as low as 1.5 V operation.[33] Other reported applications are ... 

Although germanium was the original semiconductor material in early experiments and production, it is now rarely used as such but mostly as an alloy with silicon.li l l l Some applications of silicon/ germanium are ... 

The polyaromatic mesophase (PA-MP) is a nematic, discotic, chemotropic liquid crystal. Owing to its high density (about 1.5 gcm ), its high carbon yield of about 90 %, and its thermoplasticity, it is unique as a precursor of structure carbons. An important application is the manufacture of high modulus (HM) and ultra-high modulus (UHM) carbon fibers [1]. By alloying with silicon, physical and chemical properties of the materials, such as strength, hardness and oxidation resistance, can be improved. These modified carbons were available by chemical vapor deposition (CVD) processes only up to now. The preparation by liquid phase pyrolysis is novel, economic, and thus opens a completely new field of applications. 

Hydrogen silidd—SiH,—33—is obtained as a colorless, insoluble, spontaneously inflammable gas, by passing the current of a galvanic battery of twelve cells through a solution of common salt, using a plate of aluminium, alloyed with silicon, as the positive electrode. 

The titanium alloys are not heat resisting materials being inferior to stainless steel in this respect. Recently titanium-based alloys alloyed with silicon, aluminium, zirconium (elements which considerably enhance heat resistance of technical metals Fe, Co, Ni) were elaborated in IPMS of NASU... 

It follows Ifom analysis that the hardness of surface layer rises considerably after oxidation in all alloys under study. Hardness rises in a less measure in the alloys alloyed with silicon the depth of gas saturation is also less. The additional alloying of alloys with 3 wt. % A1 does not change the depth of gas saturation and hardness of surface layer essentially. With the increase of exposure time to 30 h the depth of gas saturation changes in a considerably greater degree than hardness of surface layer. 

The common electronic components consist of integrated circuits (ICs), printed circuits (PCs), and connectors and contacts. IC conductors are made from aluminum alloys, often alloyed with silicon and copper. PC boards such as conductors and connectors are made of copper with solders consisting of lead-tin alloys. Contacts are made from copper covered with electroplated nickel or gold for improved corrosion resistance. 

Sal] Saltykov, S.A., Stable Phase Diagram Iron-Carbon Alloys with Silicon (in Russian), Litey-noe Delo, 10-11, 15-16 (1939) (Review, Phase Diagram, Phase Relations, 4)... 

Cast iron is used tor pumps, in underground sewers, and alloyed with silicone, for handling sulfuric acid. 

The foremost use of casting alloys is in the automotive industry (60% of the tonnage world-wide). These are mainly engine components elaborated from alloys with silicon, most of which also contain at least 3% copper 45100 (A-S5U3), 46200 (A-S9U3), etc. 

Dry fluorine derivatives such as antimony trifluoride SbFa, antimony pentafluoride SbFs, bromine pentafluoride BrFs, d chlorine trifluoride CIF3 have no action on aluminium, except on alloys with silicon (40000). At 30 °C, the dissolution rate of alloys 1100, 2024, 3003, 5052 and 7079 in chlorine trifluoride is below 1 p,m [8]. 

Casting alloys with silicon (series 40000), such as aluminium and 5% sUicon and A-S7G03 (42100) have a very good resistance to nitric acid at room temperature [17]. 

Aluminium and alloys of the series 1000, 3000,5000 and 6000, as well as casting alloys with silicon (series 42000), are widely used in the synthesis of acetic acid (Othmer, Hoechst, Wacker, etc. processes) [8], for its transportation (in barrels or tank wagons) and storage, and in heaters of glacial acid. 

The most commonly used metals as far as we are concerned are mild steel, and the basically similar carbon steels typified by silver steel, stainless steels which are alloys of iron with nickel and chromium, copper and its alloys with zinc or tin making up the brasses, bronzes and gunmetals, further alloys of copper with aluminium, often called aluminium bronzes, aluminium itself together with its alloys with silicon. 

Gwy] Gwyer, A.G.C., Phillips, H.W.L., The Ternary System Aluminium-Silicon-Iron in The Constitution of Alloys with Silicon and Iron , J. Inst. Met., 38, 44-83 (1927) (Phase Diagram, Experimental,, , 9)... 

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