INTERACTIONS BETWEEN La2O3 PARTICLES AND DISLOCATIONS IN Mo-La2O3 ALLOYS

The mechanical properties of molybdenum wires doped with different contents of La2O3 were in- vestigated systematically and the interaction between La2O3 particles with dislocations in Mo- La2O3 wires were observed by SEM and TEM. It is shown that Mo-La203 wires possess much higher tensile strength than the pure Mo. In wires the dislocation motion is strongly hindered by La2O3 particles, which remains up to much higher temperature. Moreover, a number of prismat- ic dislocation loops and hexagonal dislocation network have been formed in annealed Mo-La2O3 wires. The higher strength of Mo-La2 O3 than the pure Mo is attributed to the La2O3 particles dis- persion strengthening and dislocation strengthening.