Structure and mechanical properties of La₂O₃-TiC/W composites

The tungsten based composites, co-strengthened by La₂O₃and TiC with different contents, were prepared by the powder metallurgy method. The structure and mechanical properties at room temperature of La₂O₃-TiC/W composites were investigated. The results show that addition of La₂O₃ and TiC improves the mechanical properties of tungsten composites. The co-strengthening effect of La₂O₃ and TiC is better than that of La₂O₃ or TiC. Density and relative density of La₂O₃-TiC/W composites decrease with increasing the TiC content, which influences the hardness and elastic modulus of the composites. La₂O₃ with appropriate content is beneficial to improvement of relative density. The flexural strength has a maximum of 901MPa with composition of 1% La₂O₃-5% TiC/W, and fracture toughness has a maximum of 10.07 MPa·m^1/2 with composition of 1% La₂O₃-10% TiC/W. In this experiment, the La₂O₃-TiC/W composite has optimal mechanical properties with addition of 1wt% La₂O₃and 5wt%TiC. The strengthening mechanisms of La₂O₃-TiC/W composite are fine grain strengthening and load transferring.The toughening mechanisms are fine grain toughening, crack deflection and microbridging.