Cu-Cr複相合金の時効特性と強度に及ぼすZrの効果

抄録

The need for the development of the conductive materials with high conductivity and high strength is increasing to a large extent. In the previous studies, it was shown that the Cu-Cr in-situ composite has demonstrated excellent mechanical and electrical properties. The aim of the present study is to further strengthen this composite by adding a third element. In this work, Zr is selected as an alloying element because it has capacity for enhancing the precipitation hardening of the alloy.
The authors prepared Cu-15 mass%Cr-0.15 mass%Zr alloy and investigated its solidification structure, cold worked structure, and aging characteristics as follows.
(1) A band structure and heavily deformed structure exist in the Cu phase due to the accumulation of drawing strain.
(2) The specimens aged between 623 and 723 K surpass those of the as-rolled specimens with regard to 0.2 PS and σ_B.
(3) The TEM observation showed that three types of precipitates exist after aging. i.e., precipitates on vacancies, dislocations and grain boundaries. The precipitates on dislocations contribute to the secondary hardening.