Multiphase strengthening mechanism of Cu-Y2O3/W composites prepared by mechanical alloying

To prepare high-performance copper-based composites, Y2O3/W multiphase reinforced copper-based composites were synthesized through mechanical alloying and spark plasma sintering, and the mole ratio of W and Y2O3 was explored. It is found that the incorporation of W inhibited the growth of copper particle during ball milling, and facilitated the refinement of Y2O3. Compared to conditions without W addition, the Y2O3 particle diameter reduced from 97.96 nm to 33.4 nm when same mole W was added. Furthermore, copper grains were refined, resulting in a higher tensile strength of 305 MPa and elongation of 15.6 %. At 400 °C, the 5:5 sample exhibited a higher thermal conductivity of 299 W/(m·K). Nano-scale particles were uniformly distributed within the copper matrix, and the interaction between W and Y2O3 inhibited nanoparticle coarsening, leading to the formation of a more stable Y2WO6 phase during sintering, which is also better for the purification of the copper matrix.