Tungsten Carbide
Tungsten Carbide is an alloy of tungsten and carbon, made by heating tungsten powder with carbon and hydrogen at 1,400 - 1,600°C (2,550 - 2,900°F). The resulting alloy is 2-3 times as rigid as steel and has a compressive strength surpassing all known melted, cast, and forged metals. It is highly resistant to deformation and keeps its stability at both extreme cold and hot temperatures. When in its monocarbide form (chemical formula of WC), tungsten carbide rivals diamond for the hardest known material. Its impact resistance, toughness, and resistance to galling/abrasions/erosions are exceptional, lasting up to 100 times longer than steel in extreme conditions. Its properties place tungsten carbide in the metal-like substances since it is technically a ceramic cement of tungsten, carbon, and some binder (often cobalt), which is also why it cannot be heat-treated in any way. It has a density of 15.7 g/cm3 and is generally not the best electrical conductor. However, it conducts heat much faster than tool steel.
Cemented carbide is extensively used as a cutting tool material because of the advantages it offers. Initially brazed cemented carbide tips were used which could be renewed by grinding when the cutting edge turned blunt. Brazing introduces stresses in the carbide matrix. Grinding of cutting edge also introduces grinding stresses in carbide.
Indexable tooling using indexable inserts, also known as the throw-away cutting edge concept does away with brazing and grinding of cutting edges. Cemented carbide tip in form of a triangle of the square is held mechanically in a holder.
