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通过对锌铝合金ZA27进行365℃固溶和250℃人工时效,在0.1、0.3、1.0Hz 3个振动频率下,测试了铸态和固溶时效态合金从室温到400℃的阻尼随温度、频率、应变振幅的变化规律,研究了阻尼行为与相应微观组织之间的关系。根据Al-Zn二元合金平衡相图,分析了ZA27合金在平衡和实际冷速下所结晶的铸态和固溶时效组织。结果表明:铸态ZA27合金阻尼的大小与频率有关、与应变振幅无关;在300℃附近阻尼-温度曲线出现的阻尼峰位不随频率的改变而移动,说明在此温度有一级固态相变;经固溶时效后,合金组织明显细化,阻尼特性基本不变,但阻尼峰值明显高于铸态合金,表明固溶时效不改变ZA27合金的阻尼特性,但显著提高了合金的阻尼。
ZA27 alloy was subjected to solid solution at 365 ℃ and artificial aging at 250 ℃. The damping of the as-cast and as-solution aged alloys from room temperature to 400 ℃ was tested at three vibrational frequencies of 0.1, 0.3 and 1.0Hz with temperature, Frequency and strain amplitude, the relationship between damping behavior and corresponding microstructure was studied. Based on the equilibrium phase diagram of Al-Zn binary alloy, the as-cast and solution-aged microstructures of ZA27 alloy crystallized at equilibrium and actual cooling rate were analyzed. The results show that the damping of the as-cast ZA27 alloy is related to the frequency but not to the strain amplitude. The damping peak at the damping-temperature curve near 300 ℃ does not shift with the change of frequency, indicating a first-order solid-state transformation at this temperature. After solution treatment, the microstructure of the alloy is obviously refined and the damping characteristics are basically unchanged, but the damping peak value is obviously higher than that of the as-cast alloy, indicating that the solution-aging does not change the damping properties of the ZA27 alloy, but significantly improves the damping of the alloy.