Mullite-TiC-c-BN-c-ZrO2 materials Produced by Spark-Plasma Sintering and Their Properties

摘要

Different c-BN/c-ZrO2 ratios are shown to affect the phase composition, microstructure, relative density, open porosity, linear shrinkage, physicomechanical properties, and linear correlation of the elastic modulus and toughness of mullite-TiC-c-BN-c-ZrO2 samples during spark-plasma sintering at pressing load 70 MPa and 1200 - 1600 degrees C. The synthesized TiC and c-BN powders and c-ZrO2 spark-plasma sintered at 1400 degrees C are characterized by extensive phase crystallization. Mullite and TiC develop profusely in sintered samples with different c-BN/c-ZrO2 ratios. Increasing the c-BN/c-ZrO2 ratio promotes ingrowth of more c-BN than c-ZrO2 at 1200 - 1600 degrees C and causes a less uniformly and densely sintered crystalline microstructure with many pores to form at 1500 degrees C. This sample has lower physicomechanical properties, a poorer linear correlation of elasticity modulus and toughness at 1200 - 1600 degrees C, and lower crack resistance at 1500 degrees C.