Tungsten titanium carbide

W-Ti-C and W-Ta-C Systems.Pl The ternary system tungsten titanium carbide is an important material system with applications in cemented carbides for cutting tools. The solubility of WC in the TiC lattice is a function of temperature. It is 60 wt.% at 1500, reaches 90 wt.% at 2400°C, and is probably complete above 2600"C. WC is also soluble in TaC but to a lesser degree. In both systems, WC crystals precipitate upon cooling from sintering temperature and, as a result, these systems should be considered as mixed crystals or as a ceramic/ceramic composite. 

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. 

The cermet class of materials contains a large number of compositions (57). Most cermets are carbide-based, eg, WC and titanium carbide [12070-08-5] TiC. Cemented tungsten carbides are widely used for cutting tools and car parts. 

The four most important carbides for the production of hard metals are tungsten carbide [12070-12-17, WC, titanium carbide [12070-08-5] TiC, tantalum carbide [12070-06-3J, TaC, and niobium carbide [12069-94-2] NbC. The binary and ternary soHd solutions of these carbides such as WC—TiC and WC—TiC—TaC (NbC) are also of great importance. Chromium carbide (3 2) [12012-39-0], molybdenum carbide [12011-97-1], MoC, and... 

Carbide-based cermets have particles of carbides of tungsten, chromium, and titanium. Tungsten carbide in a cobalt matrix is used in machine parts requiring very high hardness such as wire-drawing dies, valves, etc. Chromium carbide in a cobalt matrix has high corrosion and abrasion resistance it also has a coefficient of thermal expansion close to that of steel, so is well-suited for use in valves. Titanium carbide in either a nickel or a cobalt matrix is often used in high-temperature applications such as turbine parts. Cermets are also used as nuclear reactor fuel elements and control rods. Fuel elements can be uranium oxide particles in stainless steel ceramic, whereas boron carbide in stainless steel is used for control rods. 

Tungsten carbide is of special interest because it retains its hardness to a high temperature compared with several other carbides. Thus titanium carbide is much harder (about 3200VHN) at room temperature (compared with... 

Silicon nitride (Si3N4) Titanium carbide (TiC) Tungsten carbide (WC) Zirconia (Zr02)... 

As noted above, the range of fibers employed does not precisely overlap with those employed for organic composites. Because the formation of the MMCs generally requires melting of the metal-matrix, the fibers need to have some stability to relatively high temperatures. Such fibers include graphite, silicon carbide, boron, alumina-silica, and alumina fibers. Most of these are available as continuous and discontinuous fibers. It also includes a number of thin metal wires made from tungsten, titanium, molybdenum, and beryllium. 

Titanium carbide/nickel and titanium carbonitride/nickel cermets are considered excellent substitutes for tungsten carbide/cobalt cermets because nickel is more abundant and less expensive than cobalt.2... 

Tetraamminelithium dihydrogenphosphide, 4590 Thorium dicarbide, 1023 Titanium carbide, 0558 Trimercury tetraphosphide, 4611 Tungsten carbide, 0560 Uranium carbide, 0559 Uranium dicarbide, 1024 Zinc phosphide, 4870 Zirconium dicarbide, 1025 METAL ACETYLIDES N-METAL DERIVATIVES METAL HYDRIDES METAL OXIDES METAL SULFIDES NITRIDES... 

Carbides of tungsten, titanium, tantalium Manufacture of cutting edges on tools Pulmonary fibrosis... 

Titanium carbide, TiC, is made by the action of carbon black on titanium dioxide at 2000 °C. It is the most important hard metallic material after tungsten carbide, and in fact is the hardest of all the metal carbides with a hardness rating of 9 on the Mohs scale - diamond is 10. In itself it is too brittle to be used pure but when mixed with the carbides of tungsten, tantalum and niobium it delivers great strength. 

Titanium carbide TiC is made by reduction of Ti02 with carbon. Compact shapes can be prepared by hot pressing. It is a significant component of commercial cermets. Tungsten carbide WC is the basic material for the bits of machining tools. 

The most important metallic hard materials, as regards quantity, are tungsten carbide, WC, and titanium carbide, TiC with a production worldwide in 1995 of 20 10- t/a and 3.5 10 t/a respectively. Also worthy of mention is the 1.5 10 t/a of titanium carbonitride, Ti(C,N), produced in 1995, which is used as the hardening component in the cermet sector. Other metallic hard materials are produced in quantities below that of titanium carbide. In individual cases they can be very important as components of alloys in the realization of particular material properties. 

Only tungsten and titanium carbide are produced in large quantities... 

After tungsten carbide, titanium carbide, TiC, is the most important metallic hard material. It is manufactured from pure Ti02 and carbon black in induction furnaces at 2000 to 2200°C ... 

---