FABRICATION AND OXIDATION BEHAVIOR OF REACTIVELY HOT PRESSED TaB2-SiC CERAMICS

Abstract

The synthesis route, microstructure, mechanical properties and oxidation behavior of TaB2-SiC composite fabricated by reactive hot pressing using Ta/B4C/Si as precursors were investigated. The reaction sequence of TaB2-SiC composite was studied thorough series of heat treatment ranging from 1000 to 1900 degrees C in Ar. Based on the reaction sequence analysis, TaB2-SiC composite was reactively hot pressed at 1900 degrees C. Its elastic modulus, flexural strength, Vickers hardness and fracture toughness were 487 GPa, 542 MPa, 17.9 GPa and 3.63 MPam(1/2), respectively. The oxidation behavior of the TaB2-SiC composites at 1500 degrees C in air exhibited passive oxidation with parabolic kinetic.