Secondary phases strengthening-toughening effects in the Mo–TiC–La2O3 alloys

Abstract Mo–TiC–La2O3 molybdenum alloys were strengthened and toughened by the synergistic action of nano-carbide particles and rare earth oxides. In this paper, the Mo–TiC–La2O3 alloy system was prepared by powder metallurgy. The microstructure was characterized by optical, scanning, and transmission electron microscopy. The mechanical properties were tested using the hardness tester and universal tensile testing machine. The grain size of the Mo–TiC–La2O3 alloy is smaller than the Mo–TiC and Mo–La2O3 alloys. The strength and elongation of annealed Mo–TiC–La2O3 alloy are 1291 MPa and 6.6%, respectively. The strength and ductility of the annealed Mo–TiC–La2O3 alloy are higher than the Mo–TiC and Mo–La2O3 alloys. According to the interfacial mismatch between the secondary phases and the matrix, along with oxygen impurities interactions, the mechanisms of strengthening and toughening of the secondary phases in the Mo–TiC–La2O3 alloy were revealed.