Fabrication of La₂O₃ dispersed Mo-Si-B alloys and its mechanical properties

Abstract

Refractory metal has been spotlighted as one of the next-generation high-temperature materials. Among the refractory metal, molybdenum (Mo) has a possibility to substitute for high-temperature materials in use currently due to its high melting point. Especially, Mo-Si-B alloys which are added silicon and boron have more potential because of its superior mechanical properties and improved oxidation resistance at elevated temperature. In addition, there are several attempts to add a 4th element in Mo-Si-B alloys recently. In this study, we introduce the La₂O₃ dispersed Mo-Si-B alloys and its mechanical properties. The Mo-Si-B-La₂O₃ alloys were fabricated by powder metallurgy and chemical reaction process. Its microstructure and distribution of oxide particle was observed by SEM and TEM analysis. Fracture toughness was measured by 3-point bending test and its fracture surface was observed by SEM.