Characterization of an industrially processed Mo-based silicide alloy

Oxidation-resistant Mo-based silicide intermetallic alloy has been produced utilizing an industrial manufacturing route at Plansee AG. Based on gas atomization of pre-sintered rods and subsequent consolidation via hot isostatic pressing, ingots with a weight of up to 20 kg were produced. Processing along this route led to good chemical homogeneity yielding impurity levels nearly as low as known for commercial powder-metallurgical molybdenum alloys. Elevated temperature mechanical properties were characterized utilizing tensile and three point bending tests. The material showed extended plasticity at temperatures as low as 1200 °C, indicating a ductile brittle transition temperature of around 1100 °C and good hot workability for component manufacturing. Additionally, the high temperature oxidation resistance of bulk material and SIBOR® coated samples has been characterized. While no total protection was observed for uncoated samples, SIBOR® coated samples showed no evidence of MoO3 sublimation up to 1650 °C for 30 h in synthetic air.