Microstructure and Properties of Cu-0.4 wt.% Al2O3 Composites Fabricated by Hot Extrusion and Cold Drawing

In the present study, Cu-0.4 wt.% Al2O3 composites were successfully prepared by internal oxidation and hot extrusion followed by cold drawing. Microstructure, texture, mechanical properties and electrical conductivity of the Cu-0.4 wt.% Al2O3 composites were systematically studied. Our results show that the cold drawn S2 sample contains a much finer grain (about 1 μm) than the extruded S1 sample (about 3 μm). The S1 and S2 samples have a typical double fiber texture, with and parallel to extrusion direction (ED) or drawing direction (DD). The ultimate tensile strength, tensile yield strength and electrical conductivity of S1 sample are 460 MPa, 375 MPa and 90% IACS, respectively. After cold drawing, the S2 sample possesses a higher ultimate tensile strength (560 MPa) and tensile yield strength (520 MPa) than S1 sample, but a slightly lower electrical conductivity (87.5% IACS) than S1 sample. After annealing at 900 °C, the S1 and S2 samples also have a high microhardness of about 125 HV, which indicates that the Cu-0.4 wt.% Al2O3 composites have an excellent thermal stability.