CuZnβ相合金のベイナイト変態におよぼすAg添加の影響

抄録

The effect of Ag addition on the bainitic transformation and the stability of the CuZn β phase alloy were studied by electron microscopy. In a Cu₅₉Zn₄₀Ag₁ alloy, a large number of small particles, probably nuclei, of bainite with diameter of 20-100 nm were observed in the early stage of aging at 513 K. During further aging, the growth of bainite plates was observed. These are similar to the bainitic behaviour in the binary CuZn alloy. In Cu₅₅Zn₄₂Ag₃ and Cu₅₀Zn₄₅Ag₅ alloys, the β phase decomposed into Cu rich and Cu poor (i.e. Ag and Zn rich) regions, and the bainite plates were grown only in the Cu rich region. By the addition of Ag more than 3 at% the β phase showed so strong tendency to the phase separation as to suppress the growth of bainite plates.