Effects of Cu content and mechanical alloying parameters on the preparation of W-Cu composite coatings on copper substrate

摘要

A novel surface coating preparation technique utilizing high-energy mechanical alloying (MA) method was used to deposit tungsten-copper composite coatings on pure copper surface using a planetary ball mill. The microstructures and elemental and phase composition of mechanically alloyed coatings at dif ferent process parameters were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS). The effects of mechanical alloying parameters on the fabricating of tungsten-copper composite coatings had been investigated. Fully dense and uniform tungsten-copper composite coatings were metallurgically bonded on the copper substrate, with an aver age thickness of ～65 μm under the optimized mechanical alloying parameters (i.e., rotation speed of 350 rpm, milling time of 9 h and powder ratio of W-30 wt.%Cu). Microhardness tests were carried out to examine the mechanical properties of the coatings. The results showed that the maximum microhard ness of the coatings reached HV_(0.1) 193, showing a great improvement upon pure copper substrate. Mechanical alloying is a complex process and hence involves optimization of a number of variables to achieve the desired results. In this work, effects of the main parameters on the preparation of tung sten-copper composite coatings were properly presented.