Effects of temperature, strain rate and specimen size on the deformation behaviors at micro/meso-scale in ultrafine-grained pure Al
Effects of temperature, strain rate and specimen size on the deformation behaviors at micro/meso-scale in ultrafine-grained pure Al
复制标题
温度、应变速率和试样尺寸对超细晶纯铝微细尺度变形行为的影响
DOI：
10.1016/j.matchar.2015.10.003
复制
发表时间：
2015-11-01
影响因子：
4.7
通讯作者：
Guo, Bin
中科院分区：
文献类型：
--
作者：
Xu, Jie;Li, Jianwei;Guo, Bin
采用等通道转角挤压（ECAP）工艺对平均晶粒尺寸约为1.0 μ m的超细晶高纯（99.999%）铝进行了8道次挤压。对UFG纯铝进行了不同温度的退火处理，得到了不同尺寸的晶粒。在高温下对直径为2.0、1.0和0.5 mm的试样进行微压缩试验，应变速率范围为3.3 x 10（-4）至0.1 s（-1）。结果表明：与粗晶纯铝相比，UFG纯铝具有较强的温度依赖性和应变速率敏感性;在微压缩过程中，粗晶和UFG纯铝的流变应力均随试样尺寸的增大而减小，表明UFG纯铝仍具有微成形的尺寸效应。然而，在微压缩的UFG纯铝的表面粗糙化效果显着改善表明，UFG材料在微成形制造MEMS部件有潜在的应用。(C)2015 Elsevier Inc. All rights reserved.
An ultrafine-grained (UFG) high purity (99.999%) aluminum with the average grain size of similar to 1.0 mu m was processed using equal-channel angular pressing (ECAP) through 8 passes. The UFG pure Al was annealed at different temperatures to obtain different grain sizes. Micro-compression testing was conducted with the specimen diameters of 2.0, 1.0, and 0.5 mm at elevated temperature and with the strain rate ranging from 3.3 x 10(-4) to 0.1 s(-1). The results show that UFG pure Al has a strong temperature dependence and high strain rate sensitivity (SRS) compared with the coarse-grained (CG) pure Al. It is found the flow stress decreases with specimen size during micro-compression of both CG and UFG pure Al, which demonstrates that UFG pure Al still exhibits the conventional size effect of micro-forming. However, the significant improved surface roughening effect in micro-compression of the UFG pure Al demonstrates that UFG materials have a potential application in microforming to fabricate MEMS components. (C) 2015 Elsevier Inc. All rights reserved.