| 摘要 |
PROBLEM TO BE SOLVED: To provide a copper alloy for electronic and electric apparatus excellent in bending workability and a stress relaxation property, and suitable for connectors or terminals used for electronic and electric apparatus and automobiles. SOLUTION: This copper alloy for electronic and electric apparatus has a composition containing, by weight, 3.0 to 9.0% Sn and Fe and P by 0.05 to 1.0% in total, in which the atomic weight ratio of Fe to P shown by the formula of [Fe/P] is 0.2 to 3.0, and the balance Cu with ineivtalbe impurities and is obtained by carrying out heat treatment of performing heating at 500 to 900 deg.C for 10 to 100 sec to form a recrystallied structure having a crystal grain size of <=5μm and thereafter performing final cold working. Sn contributes to the improvement of its mechanical properties, Fe and P are dispersed into the Cu base phase as an Fe-P compound and are made into recrystallized nuclei at the time of the above heat treatment to refine the crystal grains and to improve its bending workability. Further, a part of the above Fe-P compound reenters into solid solution at the time of the above heat treatment to improve its stress relaxation properties.
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