Ultrafine grained Cu–3Ag-xZr (x = 0.5, 1.0 wt%) alloys with high strength and good ductility fabricated through rapid solidification and cryorolling

Abstract

Ultrafine grained Cu–3Ag-xZr (x = 0.5, 1.0 wt%) alloys with high strength and good ductility were fabricated through rapid solidification in combination with cryorolling, followed by a short-time aging. The alloys after cryorolling exhibit a high strength but a relatively low ductility for the extremely high-density dislocations and large number of nano-/micro-sized particles. A significantly increased elongation is noticed with a relatively small decrease of strength in both alloys when aged at 400 °C for 10 min. The presence of ultrafine grains and increased density of nano-sized Ag precipitates during aging contribute to the retention of high strength. The reduction in dislocation density and the recovered ability of dislocation accumulation result in the increase of the ductility. Compared with the Cu–3Ag-0.5Zr alloy produced by casting and cryorolling combined with aging, the Cu–3Ag-xZr (x = 0.5, 1.0 wt%) alloys in this paper exhibit excellent combination of high strength and good ductility.