Zn-22% Al合金の減衰能と機械的性質に及ぼす銅, マグネシウム量, 熱処理および圧下率の影響

抄録

Effects of heat treatment, contents of Cu and Mg, and rolling reduction on the damping capacity, tensile strength, hardness and elongation were studied for Zn-22% Al alloys. Damping capacity of the alloys was measured in terms of internal friction using the inverted torsion pendulum method at frequency of 1 to 3Hz in atmosphere. The alloy heat-treated at 360°C for 2hrs followed by water quenching exhibits the highest internal friction (Q^-1, 4.5×10^-2). Aging at 250°C for 1hr results in about 38% decrease in the value of internal friction. Addition of 0.021%Mg lowers the internal friction of as-cast alloys containing 0.3%Cu by about 50%, whereas addition of 0.3%Cu has little effect on the internal friction of as-cast alloys (Q^-1, 1.1×10^-2). Addition of 0.3%Cu and 0.3%Cu, 0.021% Mg cause a decrease in internal friction of heat-treated alloy by about 33% and 68%, respectively. Rolling reduction of 80% results in the improvement of internal friction of heat-treated alloy containing 0.3%Cu and 0.008%Mg by 30%. Cu and Mg addition increases the tensile strength and hardness of heat-treated alloys. Simultaneous addition of 0.3%Cu and 0.008%Mg decreases elongation to the range of 1%, while addition of 0.3% Cu has no effect on the elongation of the heat-treated alloys.