Effect of alloying element Zr on microstructure and properties of Cu-Y2O3 composites

Cu-Y2O3 and Cu-Y2O3-Zr composites were prepared via mechanical alloying and spark plasma sintering, and their microstructure and properties were systematically studied by using optical metalloscope, scanning electron microscope, transmission electron microscope, conductivity and tensile tests. It is found that the microstructure of the composites greatly affects mechanical behavior and electrical conductivity. The improvement of electrical property can be attributed to the formation of coherent Y4Zr3O12 particles and the preferential nucleation of Cu4Zr phase, which improves the interface between Y2O3 and Cu matrix, and reduces the dislocation density, respectively. In addition, the Cu-Y2O3-Zr composites can achieve 265.6 MPa of yield strength, 301.0 MPa of ultimate tensile strength, 23.6% of elongation, and 92.0%(IACS) of electrical conductivity.