Influence of Addition of Al and Ti Solutes and Variable Processing Conditions on Mechanical and Electrical Properties of Cu-Cr Alloys

To apply the electric component with high efficiency, the softening problem of material should be improved. Cu-Cr alloys are recognized to be proper materials to be applied. However, the softening problem has not been solved yet. In this study, the effect of Ti and Al on mechanical property and electrical conductivity in Cu-Cr alloy was investigated. Cr content is designed to up to 0.25 wt.% in order to be expected to improve electrical conductivity. During fabrication processing, microstructure identification, Cr concentration, lattice parameter, and micro-hardness in copper matrix were measured. Then, aging condition was investigated. Resistance about over-aging is increased compared to Cu-Cr and Cu-Cr-Al alloy added to Ti. The hardness and electrical conductivity are discussed by the working conditions and heat treatment, such as rolling, solid-solution treatment, and aging process, which improve the formability also at the optimum condition. Moreover, the role of Ti contents is studied. In the Cu-Cr alloys, the addition of both Al and Ti contents keeps the hardness from being reduced. As a result, the precipitation of Cr particles and the obstacle by Al and Ti contents to be softened are observed in this study.