单向拉伸与压缩时粗晶纯锌的形变及损伤行为  

Deformation and damage behavior of coarse-grained pure zinc under unidirectional tension and compression

作　　者：李慧[1] 李小武[1] 段启强[2] 张哲峰[2] 

机构地区：[1]东北大学理学院材料物理与化学研究所,沈阳110004 [2]中国科学院金属研究所沈阳材料科学国家(联合)实验室,沈阳110016

出　　处：《中国有色金属学报》2008年第7期1171-1177,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50671023,50571104);教育部新世纪优秀人才支持计划资助项目(NCET-07-0162)

摘　　要：对具有密排六方(hcp)结构的粗晶纯锌(纯度为99.995%)试样进行单向拉伸与压缩实验,研究其形变及损伤行为。用金相显微镜和扫描电镜对试样的表面变形形貌以及断口形貌进行观察。结果表明:单向拉伸试样塑性很差,只有当应变速率很小时才表现出一定的塑性,在形变过程中几乎没有滑移系开动,只有少量孪晶产生,断口主要以解理断裂为主;单向压缩试样的塑性远优于相同应变速率下的拉伸试样,不同压缩量试样的形变与损伤方式略有不同,主要有孪生(包括二次孪晶)、滑移和裂纹的形成等;晶界在不同载荷下也有不同的表现。The deformation and damage behavior of coarse-grained pure zinc （purity of 99.995%）, with typical hcp structure, were investigated under unidirectional tension and compression. The surface deformation features and fracture surfaces of all deformed samples were observed by optical microscopy and scanning electron microscopy. The results show that under unidirectional tensile deformation, this material exhibits a very poor plasticity. Only under the case that the strain rate is very low, does the pure zinc show somewhat of plasticity. The slip systems can hardly operate under this circumstance, and only a few deformation twins can be found. Cleavage fracture is the major mode of a final failure of samples. In contrast, the samples of pure Zn present much better plasticity under compressive tests than under tensile tests at comparable strain rates. The deformation and damage behavior are slightly distinctive under different compressive strains, consisting of twinning （including formation of secondary twins）, slip deformation, cracking, etc. Grain boundaries act as varying roles under different loading conditions.

关 键 词：粗晶 纯锌 hcp结构 形变 损伤 

分 类 号：TG113.25[金属学及工艺—物理冶金]