2022 年 61 巻 1 号 p. 114-118
Cu–Zn alloys possess excellent workability and low cost, however, stress corrosion cracking resistance is poor compared to other Cu alloys. Many studies on stress corrosion cracking of Cu–Zn alloys have found that addition of Si and P to Cu–Zn–Sn alloys improves resistance to stress corrosion cracking and bending workability, but the mechanism for improving bending workability has not been elucidated yet. The purpose of this study is to evaluate the effect of the addition of Si and P on the bending workability of Cu–Zn–Sn based alloys.
In this study, we investigated the strength, bending workability, crystal orientation and microstructure of Cu–Zn–Sn–Si–P alloys processed with different rolling reduction ratios. Cu–Zn–Sn–Si–P alloys showed better bending workability and higher strength than Cu–Zn–Sn alloys. Cu–Zn–Sn–Si–P alloys also possessed small lattice strain and large crystallite size after rolling, which implies that shearing strain was suppressed from accumulating in the crystal grains and rather contributed to the formation of deformation twins. It was, therefore, concluded that the slip deformation was suppressed and the crystal grains were miniaturized by the introduction of twin boundaries, as a result, both the bending workability and the strength could be improved at the same time in Cu–Zn–Sn–Si–P alloys.
