Fabrication and microstructure of W-Cu composites prepared from Ag-coated Cu powders by electroless plating

摘要

W-Cu/Ag composites with dense microstructure and enhanced electrical and thermal properties were prepared from Cu-coated W and Ag-coated Cu powders by vacuum hot pressure sintering. Both Cu-coated W and Ag-coated Cu powders were successfully prepared by electroless plating. The microstructure and phase of sintered composites were characterized by field emission scanning electron microscope and X-ray diffraction. Several properties of sintered composites with or without employing of Ag-coated Cu powders were investigated. W-Cu/Ag composite exhibits extremely homogeneous and dense microstructure due to the transformation of sintering mode. Compared with the W-Cu composite, W-Cu/Ag composite exhibits excellent electrical conductivity (52.4%IACS) and thermal conductivity (227.4 W/m.K ), coefficient of thermal expansion can decreased to 7.47 x 10(-6)/K, Vickers hardness improved from 155.2 HV to 216.7 HV.