Coating Cu nano-sized particles on Al_2O_3 powders by a wet-chemical method and its mechanical properties after hot press sintering

摘要

Cu-coated Al_2O_3 powders were prepared by the heterogeneous method starting with Al_2O_3 and CuSO_4·5H_2O raw materials. Nanometer Al particles were used to reduce Cu resulting in a uniform coating of Cu particles on the Al_2O_3 grains. TEM, XRD and XPS were used to analyses the status of the nano-sized Cu particles on the surface of Al_2O_3 grains. The mechanical properties of the composite were investigated after hot press sintering at different temperatures. Samples with enhanced fracture toughness about 5.75 MPam~(1/2) were obtained after hot press sintering at temperature 1500℃, which is much higher than that of monolithic Al_2O_3 ceramics.