高性能阻尼Mg-Y挤压板材

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

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.