冷速对固溶态ZA27合金组织与阻尼性能的影响

对铸态ZA27合金进行365℃×3 h的固溶化处理后分别随炉冷却和空冷。利用扫描电子显微镜观察合金的室温组织,采用悬臂梁共振法测试室温下合金的声频阻尼性能。结果表明,固溶态ZA27合金炉冷后的室温组织由层片状α+ η+ε三相组成,而空冷后的室温组织由层片状α相+η相及少量没有完全分解的β相组成。空冷后的合金的层片间距比炉冷后的合金的小。阻尼测试结果表明,空冷后的合金阻尼能力高于炉冷后的合金阻尼能力,空冷合金的阻尼能力比炉冷合金的阻尼能力高约40%。分析认为空冷合金与炉冷合金阻尼能力的差异是由于组织中层片间距不同造成的。

Effect of cooling rate on damping capacities and microstructures of ZA27 alloys in solid solution state

ZA27 alloys were solution treated at 365℃ for 3 hours, and then the alloys were respectively cooled to ambient temperature in the air or in the furnace. The microstructure were observed by use of scan electron microscope, the measurement of damping capacity were made at ambient temperature by the cantilever beam technique. The experiment results show that the microstructures of the furnace - cooled alloy are composed of lamellar a phase, η phase and ε phase, and the microstructures of the air - cooled alloy consist of lamellar a phase, η phase and small amount of original β phase. The spacing between lamellar phases in the air -cooled alloy is smaller than that in the furnace - cooled alloy, which means the inter - phases boundary areas in the air - cooled alloy is larger than that in the furnace - cooled alloy, thus resulting in the damping capacity of the air - cooled alloy is nearly 40% higher than that of the furnace - cooled alloy.