INFLUENCE OF REINFORCEMENT BY THE WHISKERS OF Si3N4 AND Mg2B2O5 ON THE PROPERTIES OF cBN-BASED COMPOSITES

Yu. Yu. Rumiantseva; V. M. Bushlya; V. Z.  Turkevich; I. A. Petrusha

Yu. Yu. Rumiantseva V. Bakul Institute for Superhard Materials
V. M. Bushlya Division of Production and Materials Engineering, Lund University
V. Z. Turkevich V. Bakul Institute for Superhard Materials
I. A. Petrusha V. Bakul Institute for Superhard Materials

Keywords: whiskers, reinforcement, cBN, fracture toughness

Abstract

ABSTRACT

Three types of cBN-based composites (without whiskers, reinforced with whiskers of Si₃N₄ and reinforced with whiskers of Mg₂B₂O₅) have been obtained by High Pressure-High Temperature (HPHT) sintering. Density, Young modulus, hardness, Poisson ratio and fracture toughness have been measured for all samples. cBN-based composites, that were reinforced by the whiskers of Si₃N₄, are characterized by better mechanical properties (hardness, fracture toughness) thаn non-reinforced cBN-based composites. But reinforcement by Mg₂B₂O₅whiskers was insufficient, because Mg₂B₂O₅whiskers have low thermochemical stability.