Intergranular deformation mechanism stimulated by{10-12}extension twins in AZ81-La alloy  

作　　者：Biwu Zhu Jing Su Xiao Liu Changping Tang Wenhui Liu Luoxing Li Congchang Xu Pengcheng Guo 

机构地区：[1]College of Marine Equipment and Mechanical Engineering,Jimei University,Xiamen 361021,China [2]Research Institute of HNU in Chongqing,Hunan University,Chongqing,401135,China [3]Department of Mining and Materials Engineering,McGill University,3610 Rue University,Montreal,Quebec H3A 0C5,Canada [4]School of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan,411201,China

出　　处：《Journal of Rare Earths》2024年第12期2325-2331,I0005,共8页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(52071139,52075167,U21A20130,U20A20275);the Natural Science Foundation of Hunan(2023JJ30262,2023JJ30252);Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0886)。

摘　　要：In polycrystalline Mg-RE magnesium alloys,the lattice parameter,dislocation dynamics and critical resolved shear stress(CRSS)for various deformation modes are altered with the addition of RE atom,finally affecting deformation mode and strain accommodation mechanism among neighboring grains.Uniaxial compression tests were performed on as-extruded AZ81-La Mg alloy samples with the c-axis of the majority of crystals vertical to the compression direction.Twin variants and dominant slip systems were examined by electron backscattered diffraction(EBSD)technique.It is found by in-grain misoriention axis(IGMA)analysis that the plastic deformation is mainly accommodated by a combination of the pyramidal slip and the basal slip.The dominant twin variant is{0112}<0111>and{1102}<1101>.Here,we applied a modified displacement gradient accommodation(m-DGA)method to evaluate the selection mechanism of twin/slip in neighbour grain stimulated by{1012}extension twin.It is found that the activated slip system and/or twin variant in the neighbouring grain is determined by the accommodation of the major shear strain induced by{1012}extension twin in such a way that strain concentration along grain boundaries can be relaxed.

关 键 词：AZ81-La alloy TWINNING Slip ACCOMMODATION Rotation tensor Rare earths 

分 类 号：TG146.22[一般工业技术—材料科学与工程]