Effect of trace La on microstructure and properties of Cu-Cr-In alloys

The strength and conductivity of Cu-Cr-In alloys with trace La and different processing states were compared. Then, the influence of La on the structure and properties of the Cu-Cr-In alloy and the associated mechanisms were analyzed. The mechanical properties and microstructural evolution of the alloy were investigated via scanning electron microscopy, transmission electron microscopy, and tensile strength measurements. The results showed that the addition of 0.07wt% La to the Cu-Cr-In alloy had the effect of purifying the alloy melt and removing impurities, which improved the electrical conductivity of the alloy. However, the formation of rare earth intermetallic compounds reduced the tensile strength of the Cu-Cr-In-La alloy. After thermomechanical treatment, the Cu-Cr-In-La alloy reached a peak strength of 457 MPa and a conductivity of 85% IACS.