The influence of the dispersion technique on the characteristics of the W–Cu powders and on the sintering behavior

The influence of the dispersion technique on the sintering behavior of W–Cu composites is investigated. The dispersion of the copper phase and the fineness of the tungsten phase mostly influence the sinterability of W–Cu powders. By using high energy milling, particles containing very fine tungsten grains embedded in copper, called composite particles, can be produced. A powder consisting of composite particles has an optimal Cu dispersion and a very fine tungsten phase. This kind of powder improves significantly the sinterability of the W–Cu system in solid and in liquid states. Relative densities above 94% can be obtained easily for such powders at temperatures above the Cu melting point and for Cu contents as low as 19% in volume, even for short sintering times. A homogeneous fine structure is obtained. The sintering kinetics of such powders is described.