Tungsten carbide (chemical formula (WC)):is a chemical compound containing equal parts of tungsten and carbon atoms. In its most basic form, tungsten carbide is a fine gray powder, that constitutes the basic material forming Carbide Grades.
- Used alone or with 6 to 20 percent of other metals to impart hardness to cast iron, cutting edges of saws and drills, and penetrating cores of armor-piercing projectiles.
- It can be pressed and formed into shapes through a process called sintering to produce cutting tools and other industrial products.
Tungsten carbide is approximately twice as stiff as steel, with Young’s modulus of approximately 530–700 GPa (77,000 to 102,000 ksi), and is double the density of steel—nearly midway between that of lead and gold. It is comparable with corundum in hardness and can be polished and finished only with abrasives of superior hardness such as cubic boron nitride and diamond powder, wheels, and compounds.
For fabrication, a process developed in the 1920s is employed: the powdered tungsten carbide is mixed with another powdered metal, usually cobalt, and pressed into the desired shape, then heated to temperatures of 1,400°–1,600° C; the other metal, which melts, wets and partially dissolves the grains of tungsten carbide, thus acting as a binder or cement.
The cemented composites of tungsten carbide–cobalt are known by many trade names, including Widia and Carboloy.