Sintering of BN Based Composites with ZrC and Al under High Temperatures and Pressures

Abstract: The sintering of cubic boron nitride (cBN) based ceramic matrix materials with zirconium carbide and aluminum has been carried out under high pressures and temperatures. The performed study has revealed that the interaction between mixture components with the formation of a new phase, namely, zirconium diboride (ZrB₂) occurs at sintering temperatures above 1750°C and an applied pressure of 7.7 GPa. A further increase in the sintering temperature leads to a growth in the volume ZrB₂ content and reduces the microhardness and crack toughness of the studied materials. The flank wear of specimens under the conditions used for the processing of AISI316L stainless steel (v_c = 300 m/min, t = 300 s) grows with an increase in the sintering temperature to attain the critical value VB = 325 µm, when the specimen sintered at temperature of 2300°C is used, and VB = 200 µm for the specimen sintered at 1750°C.