Low-temperature densification, microstructures and mechanical properties of ZrB2-SiC composites with Cr3C2 additives

In this study, the densification, microstructures and elastic and mechanical properties of hot-pressed ZrB2-20 vol% SiC composites with 3-10 wt% Cr3C2 additives were examined. The effects of the Cr3C2 content on the densification, microstructures and elastic and mechanical properties are discussed. The elastic moduli of the composites were calculated using measured longitudinal and transverse soundwave velocities, and the hardness and fracture toughness of the composites were determined using indentation measurements. The results show that the elastic moduli and fracture toughness are constant and independent of the Cr3C2 content, with a shear modulus of similar to 200 GPa, Young's modulus of similar to 450 GPa and toughness of similar to 4.7MPa m(1/2). The hardness was measured as 18.2-20.9 GPa and was dependent on the Cr3C2 content. The flexural strengths of the composites were affected by the Cr3C2 content, with resulting strength values of 426-523 MPa. (C) 2018 The Ceramic Society of Japan. All rights reserved.