铸态ZK51镁合金的显微组织及其阻尼行为

Microstructure and damping behavior of as-cast ZK51 alloys

研究了铸态ZK51镁合金的显微组织及其阻尼行为。结果表明,铸态ZK51镁合金显微组织由-αMg及少量分布在晶界或晶内的Mg7Zn3相组成。室温下,铸态ZK51镁合金的阻尼值随振动频率变化不明显,只随应变振幅的增大而明显增大。在高温200℃条件下,材料阻尼性能随振动频率的增加而呈现指数下降趋势。铸态ZK51镁合金在280℃附近出现热激活弛豫阻尼峰。合金的阻尼行为可采用Granato-Lücke位错阻尼理论解释。

The microstructure and damping behavior of as-cast ZK51 magnesium alloys are investigated in the present paper. The results show that the microstructure of as-cast ZK51 magnesium alloys consists of α-Mg and a small quantity of Mg7 Zn3 phase distributing on grain boundaries or inner grains. At room temperature, damping capacity of as-cast ZK51 magnesium alloys is almost independent on the frequency but increase with strain amplitude. Whereas, damping capacity decreases exponentially with the increasing of frequency at the high temperature of 200℃. Furthermore it is necessary to point out that there is a relaxation damping peak at about 280℃. Damping mechanism of as-cast ZK51 magnesium alloys can be explained by Granato-Lücke theory.