Mechanical properties and electrical conductivity of nano-La2O3 reinforced copper matrix composites fabricated by spark plasma sintering

The nano-La2O3 reinforced copper matrix composites were fabricated by a combination method of internal oxidation and spark plasma sintering (SPS) using Cu-La alloy powders. The microstructure, mechanical properties and electrical conductivity of the La2O3/Cu composites were investigated at different sintering temperatures. The results show that the grain size of the La2O3/Cu composites is a few microns due to the in situ generated La2O3 particles, which are predominantly distributed on the grain boundaries and effectively suppress migration of Cu grain boundary during the sintering process. The ultimate tensile strength, yield strength and hardness of La2O3/Cu composite sintered at 850 °C are 1.23 times, 2.2 times and 1.5 times that of Cu-La alloy, respectively. And the electrical conductivity is as high as 92.79% IACS. However, the elongation is significantly smaller than that of Cu-La alloy. Moreover, the strengthening mechanism and conductive mechanism of the material were studied based on the experimental results.