High temperature properties of Cu–Cr–Zr alloys processed by conventional inverse extrusion of atomised powders and comparison with Conform consolidated powders

Abstract

Water atomised Cu–Cr–Zr alloy powders were consolidated by inverse warm extrusion and by the commercial continuous rotary extrusion method, Conform. Those alloys consolidated by inverse warm extrusion exhibited enhanced mechanical properties compared with their respective Conform extruded counterparts, when tested at both room and elevated temperatures. The processing parameters adopted in the inverse extrusion experiments resulted in products which retained enough amounts of solutes in solid solution, which in turn, led to improved mechanical properties after aging. Conversely, the excessive adiabatic heat generated in the Conform machine eliminated the saturation effect produced by rapid solidification, negating any possible further improvement on the mechanical properties by aging. The mechanical properties of an inverse extruded Cu–2.8Cr–0.39Zr (at.-%) alloy at temperatures above 450°C were higher than those strengths reported for Cu–Be alloys and comparable to that of Cu–Ta and Cu–Nb composites. Therefore, rapidly solidified Cu–Cr–Zr alloys can be possible candidates for replacing such alloy systems for high temperature applications.