Synthesis, microstructure and properties of MoSi2–5 vol%Al2O3 composites

MoSi2–5 vol%Al2O3 composites were prepared in situ by self-propagating combustion synthesis from Mo, Si, Al and MoO3 powders. The combustion mode and temperature of the self-propagating reaction and phase composition of the product were investigated. The results showed that the combustion mode was a steady-state self-propagating process and the composite product was composed of MoSi2 and Al2O3. MoSi2–5 vol%Al2O3 composites were consolidated by vacuum hot-pressed sintering from 1300 to 1600 °C to produce composites with high density. MoSi2–5 vol%Al2O3 composites sintered at 1400 °C exhibited a fine microstructure and excellent mechanical properties: grain size ~5 μm, Vicker׳s hardness 11.14 GPa, bending strength 435 MPa, and fracture toughness 4.53 MPa m1/2.