During sintering, hard metals are compacted using diffusion processes – but first the binder metal components of the hard metal are rendered molten at temperatures of up to 1500°C. Pores and gaps are filled, stable carbide raw material particles a drawn closer together and the volume of the component shrinks by 20 to 25 percent. After cooling, the hard carbide particles are embedded in a softer metal binder matrix, which results in the component reaching its final density and hardness. Graphite dispersions are used in the sintering of hard metals to prevent the sintered parts from adhering to the plates. Sufficient lubricating properties are essential to avoid damaging the green compacts.
