T型ECAP变形纯铝微观组织与力学性能研究  

Microstructure and Mechanical Properties of Pure Aluminum Processed by T-Shaped Equal Channel Angular Pressing(T-ECAP)

作　　者：魏伟[1,2] 马志俊[1] 魏坤霞[1,2] 杜庆柏[1] 胡静[1,2] 

机构地区：[1]常州大学材料科学与工程学院,江苏常州213164 [2]江苏省材料表面科学与技术重点实验室(常州大学),江苏常州213164

出　　处：《常州大学学报（自然科学版）》2015年第2期30-34,共5页Journal of Changzhou University：Natural Science Edition

基　　金：江苏省自然科学基金(BK2012594;BK20131144);常州市国际合作项目(CZ20130021);江苏省研究生培养创新工程项目(苏教办研[2014]1号)

摘　　要：在室温下对工业纯铝进行T型等通道挤压变形(T-ECAP),研究了挤压速度(5、12、60、120、180mm/min)和挤压道次(1道次、2道次、4道次)对纯铝微观组织与力学性能的影响。结果表明:不同挤压速度下,1道次挤压变形可以将晶粒细化到1μm以下,但是微观组织存在不均匀性;随着挤压道次的增加,晶粒逐渐细化,4道次时晶粒大小为350nm。在试样的纵向中心位置,显微硬度呈现"两端高,中间低"的漏斗状分布;随着挤压道次的增加,漏斗状的硬度分布逐渐减弱,4道次挤压变形后,硬度逐渐趋于均匀。挤压速度180mm/min时,拉伸强度呈现反常的Hall-Petch关系。随着挤压道次的增加,伸长率逐渐增大,2道次挤压变形后,拉伸强度趋于平稳。Industrial pure aluminum was processed by T-Shaped equal channel angular pressing （T-ECAP） at room temperature. Microstructure and mechanical properties of the pure aluminum after the T-ECAP process with the different extrusion speed （5,12,60,120 and 180mm/min） and the different extrusion passes （1 pass, 2 passes and 4 passes） were investigated. The results show that grain size could be refined into less than 1/1m at different press- ing speeds; however, the homogeneous microstructure was observed. With the increasing of passes, grains were gradually refined to be about 350nm after four passes. In the longitudinal center position of samples, the micro- hardness showed a funnel-shaped distribution of ＂high at both ends, low in the middle＂. With the increasing of pas- ses,the funnel-shaped distribution of microhardness weakened gradually. Microhardness tended to be uniform after four passes. The tensile strength showed an abnormal Hall-Perch relationship at the pressing speed of 180mm/ min. With an increase of passes, the elongation to failure gradually increased, and the tensile strength was saturated after two passes.

关 键 词：T型等通道变形 纯铝 微观组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG113[金属学及工艺—金属材料]