To provide a copper alloy in which strength as that of a base metal is increased, and further, elongation can be improved as well, and which is, in its turn, provided with satisfactory bending workability and has excellent thermal creep resistance as well, and to provide its production method.
The copper alloy at least comprises zirconium in the range of, by weight%, 0.005 to 0.5, is provided with a first grain group consisting of crystal grains with crystal grain sizes of ≤1.5 μm, a second grain group composed of crystal grains whose shape elongates to one direction, and having crystal grain sizes of >1.5 to <7 μm, a third grain group composed of crystal grains having crystal grain sizes of ≥7 μm, and provided that the total area ratio of the first grain group occupying in the unit area totalized regarding the crystal grain sizes is defined as α, the total area ratio of the second grain group as β, the total area ratio of the third grain group as γ, and α+β+γ=1, the total of the α and the β is higher than the γ, and also, the α is smaller than the β.
KUMAGAI JUNICHI
SUZUKI TAKESHI
Tadashi Takahashi
Takashi Watanabe
Masakazu Aoyama
Suzuki Mitsuyoshi
Kazuya Nishi
Yasuhiko Murayama