Reactive hot-pressing of ZrB2-ZrC-SiC ceramics via direct addition of SiC

A series of ZrB2-ZrC-SiC composites with various SiC content from 0 to 20 vol% were prepared by reactive hot-pressing using Zr, B4C and SiC as raw materials. Self-propagating high-temperature synthesis (SHS) occurred, and ZrC grains connected each other to form a layered structure when the SiC content is below 20 vol%. The evolution of microstructure has been discussed via reaction processes. The composite with 10 vol% SiC presents the most excellent mechanical properties (four-point bending strength: 828.6 +/- 49.9 MPa, Vickers hardness: 19.9 +/- 0.2 GPa) and finest grain size (ZrB2: 1.52 mu m, ZrC: 1.07 mu m, SiC: 0.79 mu m) among ZrB2-ZrC-SiC composites with various SiC content from 0 to 20 vol%. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.