Fabrication of W-Cu nano-crystalline composite precursor powders by mechanical alloying

W-Cu nano-crystalline composite precursor powders are fabricated by mechanical alloying (MA) at the following conditions of ball milling: with a ball powders ratio of 20:1; at a rotation speed of 500 r/min for milling time of lh to 40 h; and by ball milling for 20 min and air-cooling for 30 min. The analyses and investigations were carried out on the powders milled for different times by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The experiment results show that the nano-structural powders were synthesized by mechanical alloying in a short time of Ih under above conditions. During ball milling, CuO powders were reduced by W, part of W powders were oxidized into WO, (x=2-3). The average grain size of W particles with a spherical shape and coated by Cu is about 12.5 nm, even to a minimal value of 5-6 nm after ball milling.