Effect of Al2O3 and Cu on the microstructure and oxidation properties of Mo5Si3 composite

Al2O3/Mo5Si3 and Al2O3/Mo5Si3-Cu composites were successfully synthesized via a ball-milled mixture of MoO3, Mo, Si and Al powders and consolidated by hot pressing. The microstructure and oxidation properties of the composites were investigated. Results show that Al2O3/Mo5Si3 and Al2O3/Mo5Si3-Cu composite powders were obtained after 10 h of milling. At 600 °C, the addition of Al2O3 and Cu in the Mo5Si3 could effectively restrain its pest oxidation. At 1200 °C, the corresponding oxidation rate constants of the composites are almost an order of magnitude lower than the Mo5Si3 alloy. The composites have better oxidation resistance than the Mo5Si3 alloy.