Refractories silicide-based

Titanium silicides are used in the preparation of abrasion- and heat-resistant refractories. Compositions based on mixtures of T Si, TiC, and diamond have been claimed to make wear-resistant cutting-tool tips (157). Titanium silicide can be used as an electric—resistant material, in electrically conducting ceramics (158), and in pressure-sensitive elastic resistors, the electric resistance of which varies with pressure (159). 

In order to take advantage of the superior properties of these refractory silicides in combination with a ductile titanium matrix particle and fiber reinforced composites based on a-Ti-Si-(Al) have been developed. Two different processing routes have been performed ... 

Table 3 2-25 Physical properties of silicides and silicide-based high-temperature refractories [2.4]...

Hallowell, J.B., Maykuth, D.J. and Ogden, H.R., Silicide Coatings for Tantalum and Tantalum-Base Alloys, in Refractory Metals and Alloys III Applied Aspects, 30, Part 2, American Institute of Mining, Metallurgical and Petroleum Engineers, Dec. (1963)... 

Although the results obtained can be considered as approximate rather than accurate, they give some information about the relative strength of oxocompounds of the Group VIb elements. Nevertheless, these results were used as initial data for the development of the processes of reduction of these oxocompounds in chloride melts [150-152]. Theoretical bases and principles for monitoring the electrochemical processes of deposition of the free refractory metals and their compounds with some non-metals (carbides, borides, silicides, etc.) from molten ionic media [153] were developed. 

Low resistance, reliable, temperature-stable ohmic contacts are a prerequisite for the commercialization of SiC device technology. Still, these contacts are not yet satisfactory for a variety of reasons the annealing temperature is too high, the contacts penetrate too deep, they deteriorate when devices operate at elevated temperature, and the contact resistance is quite high. The problem of stable contacts to SiC may be resolved by using refractory metals. Refractory metals can be used to form both carbides and silicides. Silicides appear to provide a stable resistance if carbides are not present [1]. Contact systems based on such metals as nickel, chromium, titanium, cobalt and tungsten have been demonstrated for n-type SiC. Most contact systems for p-type SiC are Al-based and this imposes a limitation on the operating temperature of SiC devices with p-type contacts. 

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