Al-4％Cu合金中锯齿形屈服剪切带的变形测量  

DEFORMATION MEASUREMENTS OF SERRATED YIELDING SHEAR BANDS IN Al-4%Cu ALLOY

作　　者：项国富[1] 张青川[1] 刘颢文[1] 江慧丰[1] 伍小平[1] 

机构地区：[1]中国科学技术大学中国科学院材料力学行为和设计重点实验室,合肥230027

出　　处：《金属学报》2006年第6期619-623,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目10232030和10372098资助

摘　　要：通过高速CCD(1000 fps)连续记录Al-4％Cu合金材料在拉伸实验中出现的B型锯齿形屈服(PLC)剪切带发生前后一系列非相干光散斑图,结合数字散斑相关法图像分析技术,定量地给出了PLC剪切带及周围区域的位移和应变的空间分布,再现了PLC剪切带随时间演化发展的过程．实验结果清楚地证实了B型PLC剪切带的一种演化机制,即先在试样一侧成核,然后与拉伸轴成一定角度横向贯穿整个试样,最终形成非均匀塑性变形带．实验结果表明,在PLC剪切带形成瞬间变形带外存在弹性收缩变形．A series of white light speckle patterns was continually recorded by high-speed CCD （1000 fps） during the formation of type B serrated yielding （PLC） shear band in tensile tests of Al- 4%Cu alloy. With the image analysis technology of digital speckle correlation method, the displacement and strain spatial distribution of PLC shear band were quantitatively obtained, and the evolution process of PLC shear band with time was reproduced. The results clearly prove an evolution mechanism of type B PLC shear bands, that is, a PLC shear band first nucleates at one side of specimen, then transversely runs through the entire specimen section with a certain angle, finally forms an inhomogeneous deformation bands. The experimental results show that there exists elastic shrinkage deformation outside the band during the formation of PLC shear band.

关 键 词：AL-4%CU合金 锯齿形屈服 数字散斑相关法 剪切带 动态应变时效 

分 类 号：O344.7[理学—固体力学] O483[理学—力学]