Method of making polycrystalline dense shaped bodies based on boron carbide by pressureless sintering

摘要

The invention relates to a method of making shaped bodies of boron carbide, metal diboride and carbon, which is characterised in that a) pulverulent boron carbide is homogeneously mixed with at least one pulverulent monocarbide of the elements Ti, Zr, Hf, V, Nb, Ta in an amount corresponding to from 2 to 6% by weight of free carbon, based on the total weight of the boron carbide, b) this mixture is shaped to give green bodies having a density of at least 50% TD, c) the preformed body thus obtained is heated with exclusion of oxygen in a sintering furnace to from about 1250 to 1450 DEG C and maintained in this temperature range for from 10 to 120 minutes and d) the preformed body is subsequently sintered by heating to from 2100 to 2200 DEG C.