Self-Propagating High-Temperature Synthesis and Consolidation of MoSi2–MoB Heterophase Ceramics Alloyed with ZrB2

Abstract

In this study, we investigate the self-propagating high-temperature synthesis (SHS) and consolidation of heterophase MoSi₂–MoB ceramics alloyed with ZrB₂. A thermodynamic analysis of the combustion temperature (T_ad) and the equilibrium composition of synthesis products was performed for the Zr–Mo–Si–B system. The effect of varying Zr and B concentrations on combustion kinetics was studied in detail. The resulting heterophase SHS powders showed high structural and chemical homogeneity, though were noticeably agglomerated. We identified optimal consolidation conditions and achieved compact ceramics with a phase composition identical to the original SHS powder. The ceramic structure consists of a matrix of MoSi₂ grains with interspersed needle-like ZrB₂ grains and polyhedral inclusions of MoB. This work establishes a basis for the preparation of MoSi₂–MoB–ZrB₂ ceramics with excellent hardness, fracture toughness, thermal conductivity, and high-temperature oxidation resistance.