Temperature-Dependent Plastic Deformation Behavior of Cu-Ni Alloys: Coupled Influence of Stacking Fault Energy and Short Range Clustering

Abstract

The uniaxial tensile tests were conducted at different temperatures to explore the coupled influence of stacking fault energy (SFE) and short-range clustering (SRC) on the plastic deformation behavior of Cu-Ni alloys. The results demonstrate that the ultimate tensile strength and uniform elongation decrease with increasing temperature due to the competitive influence of SFE and SRC. Dynamic strain aging (DSA) effect is observed at 200 and 250°C, and such an effect becomes more notable with increasing Ni content. The occurrence of DSA effect is thought to be caused by pinning of moving dislocations by SRC and diffusing solute atoms. The plastic deformation mechanisms for Cu-Ni alloys is mainly governed by wavy slip of dislocations at different temperatures, since the SFE of Cu-Ni alloys are very high especially at high temperatures, and the effect of SRC can be nearly ignored.