Zn-27%Al-1%Cu-0.05%Mg合金鋳物の機械的性質に及ぼす熱処理の影響

抄録

Effects of heat treatment and stabilizing treatment on mechanical properties of cast Zn-4 to 27%Al-1%Cu- 0.05%Mg alloys were studied. An increase in Al from 4 to 12% improves the tensile strength of as-cast alloys. When the alloys containing Al 4 to 12% are heat treated at 365°C for 2 h and air, cooled, the tensile strength unchanges. When the cast alloys containing Al 22 to 27% are heat treated in the same manner, the tensile strength improves by 15 to 30%. When the heat treated alloys stabilized at 150° to 250°C for 10h, the tensile strength lowers by 30%. The heat treated alloys stabilized at 250°C for 10 h have impact values 6 times as high as those of the unstabilized alloys. If held at room temperature for 6 months, both the as-cast and heat treated alloys have nearly the same tensile strength and elongation. Stabilizing the as-cast and heat treated alloys at 100°C for 10 days lowers the tensile strength by about 25 to 30%, but raises the elongation to a range 10 to 12%.