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. (C) 2003 Elsevier B.V. All rights reserved.