Effects of Mg addition on the microstructure and softening resistance of Cu–Cr alloys

By Yuqing Sun, Peng Lijun, Guojie Huang, Haofeng Xie, X. Mi, Xin-hua Liu. 2020

141 citations recorded by the source corpus.

Abstract In this study, Cu-0.535Cr and Cu-0.535Cr-0.1 Mg are used to research the effects of Mg on the microstructure, physical properties, and softening resistance of Cu–Cr alloy. The mechanical properties and softening resistance of Cu–Cr alloy improve by adding Mg element, whereas its conductivity slightly decreases. The hardness, electrical conductivity, tensile strength, and yield strength of Cu–Cr–Mg alloy are 170.1 HV, 77.8% IACS, 519 MPa, and 472 MPa, respectively, after cold rolling by 60% and aging at 450 °C for 60 min. The strengthening mechanism of the studied alloys aging at 450 °C for 60 min is chiefly ascribed to the Orowan precipitation and dislocation strengthening, and is slightly contributed by solid solution strengthening. The softening temperatures of Cu-0.535Cr and Cu-0.535Cr-0.1 Mg alloys are 525 °C and 575 °C, respectively. The softening of the alloys is accompanied by the growth of Cr precipitates and the occurrence of recrystallization behavior. Mg atoms diffuse from the Cr precipitates to the Cu matrix during annealing, and the Mg atoms distributed in the precipitate–matrix interface retard the growth and coarsening of Cr precipitates. The fine Cr precipitates and Mg atoms dissolved in the matrix fix the dislocation and boundary, resulting in excellent physical properties and softening resistance of Cu–Cr–Mg alloy.

Subfields: Aerospace Engineering, Materials Chemistry, Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/92e43b441ec5483ee71a7ade489490e995f42769