拉伸变形Al-Si合金中Si颗粒相对于晶粒旋转的原位证据  

In-situ evidence for rotation of Si particles with respect to grains in tensile-deformed Al−Si alloys

作　　者：肖遥 兰新月 鲁强 杜勇[1,2,3] 李凯 Yao XIAO;Xin-yue LAN;Qiang LU;Yong DU;Kai LI(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;National Key Laboratory of Science and Technology for National Defense on High-strength Structural Materials,Central South University,Changsha 410083,China;Advanced Research Center,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]中南大学轻质高强结构材料国防重点实验室,长沙410083 [3]中南大学高等研究中心,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第6期1655-1664,共10页中国有色金属学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.52071340,51820105001)。

摘　　要：为确定Si颗粒在拉伸变形过程中是否相对于基体晶粒发生旋转,采用原位拉伸扫描电子显微镜(SEM)和离位背散射电子衍射(EBSD)相结合的方法,研究Al-Si合金在拉伸变形过程中Si颗粒旋转与晶粒旋转之间的关系。通过对比晶粒的EBSD三维取向的平面投影信息与Si颗粒的原位SEM信息,发现Si颗粒在样品表面的平面上具有明显的相对旋转。此外,根据EBSD数据的中心点平均取向差(KAM)分析,发现Si颗粒的较大相对旋转会引入更高密度的几何必需位错(GND),这会在颗粒附近的基体中产生较强的加工硬化效应。总之,Si颗粒的相对旋转度越大,加工硬化效果越强。To clarify whether the Si particles rotate with respect to the matrix grains during tensile deformation of Al−Si alloys,in-situ tensile SEM and ex-situ EBSD were coupled to investigate the relationship between Si particles’rotation and grain rotation.By comparing the on-plane projection of 3D orientations of grains revealed by EBSD and in-situ SEM observations of Si particles during deformation,noticeable relative rotation of Si particles on the sample surface plane with respect to the matrix grains was found.Besides,greater relative rotation of the Si particle was found to introduce a higher density of geometrically necessary dislocations(GNDs)which can cause work-hardening effects in the matrix nearby the Si particles,according to kernel average misorientation(KAM)analysis of EBSD data.In summary,the larger relative rotation of Si particles can cause higher work-hardening effects.

关 键 词：AL-SI合金 相对旋转 几何必需位错 原位拉伸 塑性变形 加工硬化效应 

分 类 号：TG146.21[一般工业技术—材料科学与工程]