The vacuum horizontal continuous casting method was used for preparing Cu-4.5 wt.% Ag alloy rod containing few oxygen. The evolution of microstructure was observed by metallographic microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the hardness and electrical conductivity of Cu-4.5 wt.% Ag alloy aged at 450 °C for 12 h were increased by 60 HV and 12 %IACS than solution treated alloy. TEM observation showed that the continuous precipitates of Ag are uniformly distributed in matrix with the form of particles and strips. Through calculation, the strength increment of peak aged Cu-4.5 wt.%Ag alloy from solid solution hardening and precipitation hardening are 86 MPa and 136 MPa, respectively.
The softening behavior of a cold-drawn Cu–Cr–In alloy was investigated during annealing between 450 °C and 700 °C. The properties and microstructure evolution of the alloy were characterized using a microhardness tester, electron back-scatter diffraction, and transmission electron microscopy. Elemental In addition was found to hinder the dislocation movement and delay the recovery and recrystallization of the Cu–Cr–In alloy. The experimental data were analyzed using the Johnson–Mehlv–Avramiv–Kolmogorov model. The activation energy of recrystallization of the 60% cold-drawn Cu0.54Cr0.17In alloy was 188.29 ± 18.44 kJ/mol, and the recrystallization mechanism of the alloy was attributed mainly to Cu self-diffusion.
Microstructure, precipitation hardening response, and mechanical and physical properties of Cu-Cr-Ag alloy and Cu-Cr-Ag-Ce alloy have been investigated using transmission electron microscopy, scanning electron microscope, optical microscope, electrical conductivity analysis, and tensile test. The influence of element Ce on the matrix refinement, impurity removal, and precipitation in the Cu-Cr-Ag alloys has been analyzed. The experimental results show that the strength and electrical conductivity of Ce containing alloys are greater than those of Ce-free alloys after each processing step. Improvement of strength and electrical conductivity of the Cu-Cr-Ag alloy by adding Ce element is attributed to removing oxygen and sulfur from as-cast alloy.