Fabrication and characterization of W-15Cu composite powders by a novel mechano-chemical process

摘要

W-Cu nanopowder was successfully prepared by a novel mechano-chemical method, in which WO_3 and CuO powders were first jet-milled in a high-pressure airflow, then reduced in H_2 to convert into W-Cu composite powders. The starting and milled WO_3 and CuO powders, as well as the resulting W-Cu powders were characterized by X-ray diffraction analysis (XRD), transmission electron microscope (TEM) and laser particle size analysis. Property of the sintered W-Cu compacts was also investigated. It was shown that jet milling effectively reduces particle size of the starting WO_3 and CuO powders. The W-Cu composite powder fabricated by the mechano-chemical process has nanosize of less than 100 nm and high-dispersed and homogeneous distribution of W and Cu components. The W-Cu composite powder exhibits high sinterability, and relative density of near 99% of the theoretical was achieved for W-Cu compacts sintered at 1200 ℃. Furthermore, the sintered W-Cu parts showed good physical and mechanical properties. Maximum electrical and thermal conductivity are 185 Wm~(-1) K~(-1) and 25 m Ω~(-1) cm~(-1) for W-Cu compacts sintered at 1200 ℃, respectively, and bending strength and Vickers hardness are 673 and 372 MPa, respectively.