高阻尼镁合金Mg-0.6%Zr和Mg-Ni中内耗峰分析

在高阻尼镁合金研究中，发现了与合金室温下高阻尼性能有关的宽的弛豫内耗峰，该峰为位错内耗峰；该峰是基面位错在热激活作用下运动与点缺陷（空位与溶质原子）相互作用产生。同时在高阻尼合金Mg-Ni和Mg-0.6%Zr中发现了晶界内耗峰。有必要指出的是合金的显微组织会影响晶界弛豫：随着Ni的质量分数增加，晶粒细化同时晶界内耗峰向低温处迁移；同Mg-0.6%Zr合金相比，加入少量的Y后,Mg-0.6%Zr-Y合金晶界弛豫峰向高温处推进。

Illustration of internal friction peaks observed in Mg-0.6%Zr and Mg-Ni high damping magnesium alloys

A broad relaxation peak, which contributes to the high damping capacity around room temperature, has been obtained in all our investigated high damping magnesium alloys. This peak is a dislocation-related relaxation peak, which is probably caused by the interaction between dislocation and point defects (vacancy and solid atoms) during the dislocation movement on the basal plane actived by thermal. The grain boundary relaxation peak also has been observed in both Mg-Ni and Mg-0.6%Zr high damping alloys. However, it is necessary to point out that microstructure can affect the gain boundary relaxation. With Ni content increasing, the grain is refined and the grain boundary internal friction peak shifts to lower temperature. Compared with Mg-0.6%Zr alloy, the grain boundary internal friction peak shifts to higher temperature after adding a little yttrium(Y).