非比例加载下Zr-4合金的宏观响应及其微观机理  

MACROSCOPIC RESPONSE AND MICROSCOPIC MECHANISM OF ZIRCALOY-4 UNDER NONPROPORTIONAL LOADING

作　　者：肖林[1] 匡震邦[2] 

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049 [2]上海交通大学工程力学系,上海200030

出　　处：《金属学报》1998年第3期242-248,共7页Acta Metallurgica Sinica

基　　金：国家自然科学基金!59601009;19672048;核工业科学基金!H7196EY702

摘　　要：研究了Zr-4合金在双向拉-拉复合加载过程中，沿不同非比例加载路径下，材料塑性变形行为及其微观机理结果表明，加载路径的突然变化，引起应力矢量较应变增量矢量滞后．宏观应力响应表现为瞬时软化，随后重新强化特征，变形软化和重新强化的程度及其变化率与转折角大小及转折方向有关．电镜观察表明，单调折线加载后形成两组平行的位借线；有约束单轴循环变形后形成了平行的位错线；双三角形路径下，在平行的位错墙内部形成了许多位错线；椭圆和圆形路径下有形成位错胞的趋势.Monotonic and cyclic plastic deformation behaviour and microscopic mechanism of zircaloy-4 under biaxial tension loading along different loading paths were investigated. The results show that an obvious stress delay appears in comparison with the strain increment vector after the turning point of a strain path. The equivalent stress suddenly drops then increases, and the firstly softening and subsequently haxdening degrees are related to the turning angle values,the path length and turning direction. Therefore, the influence of the deformation history and the coupled effects among strain components on the response can not be neglected. By TEM, the deformed dislocation configurations are parallel dislocation lines in uniaxial tension with constraint condition, a lot of free dislocation lines between channeals in double-triangle, and embryonic cells in elliptical and circular loading, respectively. The correlation between macroscopic deformation behaviour and microscopic deformation structure is discussed, finally.

关 键 词：ZR-4合金 复合加载 本构方程 微观机理 位错组态 

分 类 号：TG113[金属学及工艺—物理冶金] TG146.414[金属学及工艺—金属学]