Preparation of W/Cu Functionally Graded Material
A W/Cu system functionally graded material (FGM), which may be used as plasma facing component for fusion reactors, was prepared by inserting W-Cu layers with gradient composition between tungsten and copper alloy plates. W-Cu gradient layers were hot-press sintered from W-Cu powder mixtures added with zinc powder as the sintering aid, whose relative density increased with sintering temperature, reaching a value higher than 96% at 850°C. XRD and SEM measurements showed that the sintered W-Cu gradient layers were the mechanical mixtures of W and Cu. A wholly dense W/Cu system FGM was then obtained at 850°C by hot-press, whose composition and structure changed gradually. The finite element method (FEM) calculation showed that the residual stresses in the W/Cu FGM were effectively reduced as compared with the directly-bonded W/Cu joint.
Akira Kawasaki, Akinaga Kumakawa and Masayuki Niino
C. B. Wang et al., "Preparation of W/Cu Functionally Graded Material", Materials Science Forum, Vols. 631-632, pp. 431-434, 2010