Spark plasma sintering of ZrB2–SiC composites with in-situ reaction bonded silicon carbide

Abstract

This work presents a new hybrid manufacturing process to produce ZrB2–SiC ceramics with the SiC phase synthesized in situ by reaction bonding. Since ZrB2–SiC composites properties strongly depend on their grain size, finer and thus more expensive powders are usually employed. In the first part of the process, silicon carbide with a fine microstructure was produced by the reaction bonding between silicon powders and carbon derived from powders and pyrolysed phenolic resin The latter, being fluid before polymerization, filled the interstices between the powders thanks to the high pressure applied. Because of this behavior, after spark plasma sintering, the resulting microstructure presents the SiC phase dispersed between the ZrB2 grains in a different ways when compared with the standard ceramic powders consolidation methods.