梯度层与基体层体积配比对Mg-Gd-Y合金力学性能的影响  

Effect of Volume Ratio of Gradient-structured Layer to Matrix Layer on Mechanical Properties of Mg-Gd-Y Alloy

作　　者：吴蒙 宁江利 苑潇逸 陶世洁 徐博 WU Meng;NING Jiang-li;YUAN Xiao-yi;TAO Shi-jie;XU Bo(College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,China)

机构地区：[1]华北理工大学冶金与能源学院,河北唐山063210

出　　处：《稀有金属与硬质合金》2021年第4期55-61,共7页Rare Metals and Cemented Carbides

基　　金：国防基础科研计划项目(JCKY2018407C008);华北理工大学杰出青年基金(JQ201702);。

摘　　要：采用表面机械研磨处理(SMAT)工艺及双面同时研磨,在Mg-Gd-Y合金表层产生梯度结构,并对研磨试样进行短时退火处理优化性能。通过改变研磨时间和试样厚度,研究梯度层与基底层体积配比对合金力学性能的影响。结果表明:研磨试样在近表面层产生梯度组织,依次可划分为最表层的严重变形区、次表层的中等变形区和最底层的基体区。随着研磨时间的延长,梯度层厚度呈增长趋势。较薄的试样在研磨初期由于发生弹性和塑性变形,梯度层厚度增长较慢;厚度在2 mm以上的试样,研磨200 min后获得的梯度层厚度相近。随着梯度层体积占比增大,试样整体的屈服强度呈上升趋势。研磨试样经短时退火后,梯度层晶粒明显长大,位错和孪晶明显减少,导致合金屈服强度下降,而断裂延伸率得到大幅提升。The surface mechanical attrition treatment(SMAT)process and double-sided simultaneous attrition were used to produce a gradient structure on the surface of Mg-Gd-Y alloy,and the SMAT samples were subjected to short-term annealing treatment to optimize their performance.By changing SMAT duration and sample thickness,the effect of the volume ratio of gradient-structured layer to matrix layer on mechanical properties of the alloy was studied.The results show that the SMAT samples have gradient structure in the near-surface layer,which can be divided into the severely deformed area at the most surface layer,the moderately deformed area at the sub-surface layer,and the matrix area at the bottom layer in turn.With the increase of SMAT duration,the thickness of the gradient-structured layer shows an increasing trend.The thickness of the gradient-structured layer in the relatively thin samples slowly increases due to elastic deformation and plastic deformation in the initial stage of SMAT.For samples with a thickness of more than 2 mm,their gradient-structured layers have similar thickness after SMAT for 200 min.As the volume ratio of the gradient-structured layer increases,the overall yield strength of the samples shows an upward trend.After the SMAT samples are subjected to short-term annealing,the grains of the gradient-structured layer significantly grow up,and dislocations and twins are significantly reduced,resulting in decreased yield strength and significantly improved elongation at break of the alloy.

关 键 词：MG-GD-Y 梯度结构 表面机械研磨处理 短时退火 

分 类 号：TG146.45[一般工业技术—材料科学与工程]