| 摘要 |
This copper alloy contains at least zirconium in an amount of not less than 0.005% by weight and not greater than 0.5% by weight, includes a first grain group including grains having a grain size of not greater than 1.5 mum, a second grain group including grains having a grain size of greater than 1.5 mum and less than 7 mum, the grains having a form which is elongated in one direction, and a third grain group including grains having a grain size of not less than 7 mum, and also the sum of alpha and beta is greater than gamma, and alpha is less than beta, where alpha is a total area ratio of the first grain group, beta is a total area ratio of the second grain group, and gamma is a total area ratio of the third grain group, based on a unit area, and alpha+beta+gamma=1.
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