Microstructure and mechanical properties investigation of W Cu composites prepared from dual-layer coated powders

Dual-layer (Cu and Ni coated W) coated powders were successfully prepared by electroless plating to fabricate high-density WCu composites with excellent mechanical properties. Field emission scanning electron microscope, transmission electron microscope and X-ray diffraction were used to analyze the microstructure and phase of sintered composites. Vickers hardness and bending strength of sintered composites were investigated. The results show that W powders were coated by Ni layer with a dense and uniform cell structure, the thickness of the Ni layer increased with the increasing of the content of Ni. Then Ni coated W composite powders were covered by Cu layer to prepare dual-layer composite coated powders (Cu and Ni coated W) with uniform and dense structure. WCu composites prepared from dual-layer composite coated powders with 2.48 wt% content of Ni can achieve high densification and strong mechanical strength due to the transformation of sintering mode and the formation of Ni3P phase. Vickers hardness and bending strength can achieve to 257.9 HV and 953.80 MPa, respectively.