微量Sc和Zr对锌铝共析合金微观结构和阻尼性能的影响

Effect of trace Sc and Zr on microstructure and damping capacity of Zn-22%Al alloy

采用金相显微镜、扫描电镜、XRD及阻尼性能测试等手段研究了添加Sc和Zr对锌铝共析合金阻尼性能的影响。结果表明 :0 .2 1%Sc和 0 .15 %Zr使锌铝共析合金铸态组织显著细化 ,阻尼性能提高 ,阻尼稳定性提高 ;两种合金Zn 2 2 .1%Al和Zn 2 2 %Al 0 .2 1%Sc 0 .15 %Zr分别在约 2 0 8℃和 195℃出现内耗峰。分析认为Al3 Sc及Al3 (Sc ,Zr)质点对α/α ,α/β ,β/β界面的非弹性粘滞运动的阻碍引起高阻尼 ,并致使峰位移向低温。同时 ,这些质点有效地阻止位错的迁移和亚晶的形成、长大和合并 。

The effect of trace Sc and Zr on the internal friction and damping stability of Zn-22%Al eutectoid alloy was investigated. The experimental results show that the addition of 0.21%Sc and 0.15%Zr can improve the as-cast structure of the alloy and increase the damping capacity and damping stability of Zn-22%Al alloy. An internal friction peaks were observed about 208?℃ and about 195?℃ respectively in the present Zn-22.1%Al and Zn-22%Al-0.21%Sc-0.15%Zr alloys. The improvement of the structure and the damping capacity was found to be directly attributed to the precipitation of Al 3Sc and Al 3(Sc, Zr) phases from the aluminum alloy matrix. The internal friction mechanisms of the alloy were put forward.