Titanium carbide powder

S. Y. Sharivker, I. P. Golovinskaya, 1. N. Vorob eva, and V. M. Bunin, Wear of tungstenless hard alloys based on SHS-titanium carbide. Powder Metall. Metal Ceram. 1996, 35, 55-57. 

Titanium carbide powder is prepared by the reaction of Ti02 with carbon at 2000°C or above in hydrogen by the carburi2ation of titanium sponge by the auxiliary bath technique, or by plasma-CVD. Titanium carbide coatings are deposited by CVD, evaporation or sputtering (see Chs. 14 and 15). 

T Ishigaki, T Sato, Y Moriyoshi, MI Boulos. Influence of plasma modification of titanium carbide powder on its sintering properties. J Mater Sci Lett 14 1694, 1995. 

Processing. Tungsten carbide is made by heating a mixture of lampblack with tungsten powder in such proportions that a compound with a combined carbon of 6.25 wt % is obtained. The ratio of free-to-combined carbon is of extreme importance. Tantalum and titanium carbides are made by heating a mixture of carbon with the metal oxide. Multicarbide powders, such as M02C—WC, TaC—NbC, and TiC—TaC—WC, are made by a variety of methods, the most important of which is carburization of powder mixtures. 

Titanium carbide may also be made by the reaction at high temperature of titanium with carbon titanium tetrachloride with organic compounds such as methane, chloroform, or poly(vinyl chloride) titanium disulfide [12039-13-3] with carbon organotitanates with carbon precursor polymers (31) and titanium tetrachloride with hydrogen and carbon monoxide. Much of this work is directed toward the production of ultrafine (<1 jim) powders. The reaction of titanium tetrachloride with a hydrocarbon-hydrogen mixture at ca 1000°C is used for the chemical vapor deposition (CVD) of thin carbide films used in wear-resistant coatings. 

Titanium carbide may be prepared by a thermochemical reaction between finely divided carbon and titanium metal powder. The reaction proceeds exothermically. 

It also reacts with carbon. There are cases of spontaneous ignition with ti-tanium/powdered carbon mixtures prepared for the purpose of producing titanium carbide. 

Powdered titanium carbide detonated spontaneousiy in oxygen. It was thought that the detonation was caused by a spark of static electricity. 

Of a series of powdered refractory compounds examined, only lanthanum hexa-boride, hafnium carbide, titanium carbide, zirconium carbide, magnesium nitride, zirconium nitride and tin(II) sulfide were dust explosion hazardous, the 2 latter being comparable with metal dusts. Individual entries are ... 

Laser Hardening and Modification. Lasers are used to surface harden ductile steels and improve the toughness to a depth of 0.35 min or more. Lasers can also be used to bond solid or powder coatings to a surface. Typical coalings are nickel or titanium carbide on iron, and nickel, cobalt, manganese, and titanium carbide. TiC. on aluminum. I1 sc of lasers with other specialized coating methods is common. 

The kinetics of diamond powder infiltration with cobalt of VK15 sintered carbide and Co-Mo and Co-Ti melts was studied experimentally at 8 GPa (Fig, 1). Confidence intervals for T and k values, the reliability being a= 0,95, do not exceed 8 %. According to [3], the limit of WC solubility in Co attains 10 mass % or 3.2 at. %. The additive contents of Co-Mo and Co-Ti alloys was 10 mass % (accordingly, the atomic portions were 0.12 Ti and 0,064 % Mo). Samples of alloys were sintered from mixtures of cobalt-molibdenum and cobalt-titanium hydride powders in a vacuum furnace at 1000 °C. 

Adachi, S., Wada, T., Mihara, T., Miyamoto, Y., Koizumi, M., and O. Yamada, Fabrication of titanium carbide ceramics by high-pressure self-combustion sintering of titanium powder and carbon fiber. J. Am. Ceram. Soc., 72, 805 (1989). 

A similar regularity in the mass distribution of the various Zr-substituted met-cars was observed for different Ti/Zr molar ratios and was used as an argument in favor of a pentagonal dodecahedron structure in which all metal sites are equivalent. In subsequent studies, binary metal metallocarbohedrenes of titanium and other metals Ti cM Ci2 (x -I- y = 8) have been obtained either by the standard method using pure metal powders of Ti and M as a target for laser vaporization and a mixture of helium with 10% methane as carrier gas (M = Nb, Ta, Y, Si), or by direct laser vaporization of a mixture of titanium carbide and pure M metal (M = Y, Nb, Mo, Ta, W). ... 

Carbides of metals and other elements have been produced by this approach, including carbides of boron, silicon, titanium, zirconium, hafnium, vanadium, niobium, molybdenum, tungsten, tantalnm, and thorium (Funke, Klementiev, Kosukhin, 1969 Sheppard Wilson, 1972 MacKinnon Wickens, 1973 Chase, 1974 Steiger Wilson, 1974 Swaney, 1974 MacKinnon Renben, 1975). The produced caibide particles are very small their diameter is usually about 20-200 mu. Halides are mixed with hydrocarbons, usually in a ratio H2 Me = 2-30. The gas mixture is heated up in plasma to temperatures of 1300-4000 K time of synthesis exceeds 50 ms. As an example, production of submicron boron carbide powder from gaseous boron trichloride and methane occurs in the strongly endothermic process ... 

A variety of other ternary and quaternary carbides and carhonitrides is especially interesting for use in metal cutting tools in the form of layers, and powder particles have been investigated recently for their specific heat, temperature and thermal conductivity [66]. The behavior of the heat conductivity of most of these compounds is similar to that of the group IVB carhonitrides for (near) stoichiometric composition showing a positive curvature of heat conductivity as a function of temperature. Interestingly, however, Nb- and Mo-containing ternary titanium carbides and nitrides and quaternary titanium carhonitrides show a hnear behavior in the same temperature interval. 

Titanium silicon carbide MAX phase was synthesized by pressureless sintering of ball milled TiC and Si powders of six different compositions. The sintering reactions were evaluated in situ by dilatometer analysis under flowing argon gas. The as-sintered samples were evaluated using mainly x-ray diffraction (XRD) analysis. This study showed that titanium carbide, silicon carbide and titanium disilicide were present as intermediate or secondary phases in the samples. 

Figure 3 shows x-ray diffractograms of the samples sintered under vacuum for 2 hours and 30 min in 1250 C. The B sample with the lowest amount of silicon in the starting powder differs from the other samples. It is the only sample which does not contain silicon carbide (SiC) and titanium disilicide (TiSi2). All samples contained titanium silicon carbide MAX phase (TisSiCj) and titanium carbide (TiC). 

These carbides also have similar properties and characteristics. Of the three, titanium carbide has been more investigated and is the most important from an application standpoint. It is produced industrially on a large scale in the form of powders, molded shapes, and thin films. The... 

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