RE及Al5TiB对ZA84镁合金阻尼性能的影响

研究了变质剂RE及Al5TiB对Mg-8Zn-4Al-0．3Mn（ZA84）镁合金阻尼性能的影响。研究表明，RE的加入降低了合金在低温（〈80℃）时的阻尼性能，但明显提高了合金在高温（≥80℃）时的阻尼性能；而Al5TiB的加入则同时提高了合金室温及高温阻尼性能。经Al5TiB变质的合金在室温时即表现出了Q^-1=0．01的高阻尼。由于高温下合金中相的软化及界面的粘性滑动，ZA84镁合金在高温时存在一个温度内耗峰，加入RE后推迟了合金中温度内耗峰的出现温度。分析认为，加入RE及Al5TiB后合金的阻尼机制主要是位错机制和界面机制。可动位错密度越高，晶粒越细，晶界和相界面越多，阻尼性能越好。

Effect of RE and Al5TiB on Damping Properties of ZA84 Magnesium Alloys

The effect of inoculation on the damping capacity of Mg - 8Zn - 4Al- 0.3Mn alloys is studied. The results show that by the addition of RE,the damping capacity of ZA84 alloys is reduced at low temperature, while the damping capacity at high temperature is obviously improved. The damping capacity of ZA84 alloys at both low temperature and high temperature is improved by the addition of A15TiB. The damping capacity can reach Q^-1= 0. 01at room temperature by the addition of A15TiB. There exists a damping peak in all of the alloys at different temperature because of the viscous sliding or slipping of the grain boundaries and interfaces at high temperature. It is found that the addition of RE can delay the temperature of damping peak. The main damping mechanism of ZA84 magnesium alloys with RE and A15TiB is the interface damping and the dislocation damping. The more the dislocations and grain boundaries or interfaces are, the higher the damping capacity of ZA84 alloy.