近年来，随着交通运输业、航空航天业和电子工业的迅速发展，噪声和振动已成为环境污染的三大公害之一，减震降噪显得尤为重要。因此，开发具有高阻尼、低密度、高强度的镁合金材料具有重大意义。
来自西南交通大学的唐尧天，尹冬弟等人，系统研究了Y元素含量对室温和高温下Mg-Y合金阻尼性能和力学性能的影响，通过G-L模型分析了阻尼机制，并综合评价了力学性能和阻尼性能。实验结果表明，室温下Y元素的增加会使Mg-Y挤压板材的阻尼性能变差，其阻尼行为吻合G-L位错塞积模型，表示其阻尼机制由位错主导。在高温下位错阻尼不是Mg-Y挤压板材唯一机制，温度越高，晶界滑移造成的阻尼越明显，Y元素在晶界偏聚的倾向抑制了晶界的滑移，阻尼机制的临界转变温度从50℃(纯Mg)增加到290℃(Mg-3Y)。通过与多种阻尼镁合金对比，Mg-1Y挤压板材有较好的力学性能和优异的阻尼性能。在325℃的高温下，Mg-1Y和纯Mg具有相当的阻尼值(0.09)，但是其屈服强度是纯Mg的3.4倍。Mg-3Y合金的阻尼值为0.07，虽然略低于阻尼值为0.09的纯镁，但其屈服强度为是纯Mg的5.3倍。综上所述，Mg-Y基合金具有成为高性能阻尼合金的潜力，尤其具有高温应用潜力。
图1 纯Mg和Mg-xY(x=0, 0.5, 1.0, 3.0 wt. %)挤压板材的阻尼行为
文章发表
该文章发表在《Journal of Magnesium and Alloys》2019年第七卷第3期：
[1] Y.T. Tang, C. Zhang, L.B. Ren, W. Yang, D.D. Yin, G.H. Huang, H. Zhou, Y.B. Zhang, Effects of Y content and temperature on the damping capacity of extruded Mg-Y sheets, J Magnes Alloy 7(3) (2019) 522-528.
中文摘要
本文系统地研究了Y元素含量对挤压态Mg-xY (x＝0.5, 1.0, 3.0 wt.%) 板材阻尼性能的影响，并且探究了其阻尼性能(Q-1)和屈服强度之(Rp0.2)间的关系。在室温下，随着Y含量从0.5%增加到3%，Q-1从0.037下降到0.015，变化非常明显。应变振幅和阻尼之间的关系与G-L位错塞积阻尼模型吻合良好，证明室温下阻尼机制由位错主导。随着温度逐渐升高，在温度-阻尼曲线中，G-L位错塞积模型曲线偏离线性，这说明除了位错阻尼外，晶界的滑动或是另一影响阻尼的机制。随着Y含量从0%增加到3%，临界转变温度从50℃增加到290℃，这一结果被归因于Y在晶界处的偏析抑制了晶界的滑动，这与最近发现的稀土元素偏析趋势一致。在325℃的高温下，Mg-1Y板材的阻尼值比纯镁高3倍以上，这证明Mg-Y具有成为高温应用下高阻尼材料的潜力。与高阻尼材料Mg-0.6Zr相比，Mg-1Y挤压板材在室温下表现出略高的屈服强度和Q-1。在325℃的高温下，Mg-1Y挤压板材具有与纯Mg相当的Q-1，但其屈服强度是纯Mg的3倍以上。本研究表明，Mg-Y基合金具有开发成为高性能阻尼合金的潜力，尤其具有在高温应用的潜力。
Abstract
The damping behavior of extruded Mg-xY ( x = 0.5, 1.0, 3.0 wt.%) sheets were investigated in detail concerning the effects of Y addition and temperature, and the relationship between damping capacity and yield strength was discussed. At room temperature (RT), with Y content increasing from 0.5% to 3.0%, the damping capacity ( Q−1 ) significantly decreased from 0.037 to 0.015. For all the studied sheets, the relationship between strain amplitude and Q−1 fitted well with the Granato and Lücke (G-L) dislocation damping model. With temperature increased, the G-L plots deviated from linearity indicating that the dislocation damping was not the only dominate mechanism, and the grain boundary sliding (GBS) could contribute to damping capacity. Consequently, the Q−1 increased remarkably above the critical temperature, and the critical temperature increased significantly from 50°C to 290°C with increasing Y contents from 0 to 3.0 wt.%. This result implied that the segregation of Y solutes at grain boundary could depress the GBS, which was consistent with the recent finding of segregation tendency for rare-earth solutes. The extruded Mg-1Y sheet exhibited slightly higher yield strength ( Rp0.2 ) and Q−1 comparing with high-damping Mg-0.6Zr at RT. At an elevated temperature of 325°C, the Mg-1Y sheet had similar Q−1 but over 3 times larger Rp0.2 than that of the pure Mg. The present study indicated that the extruded Mg-Y based alloys exhibited promising potential for developing high-performance damping alloys, especially for the elevated-temperature application.