Precipitation on stacking faults in Mg–9.8wt%Sn alloy

作     者：C.Q.Liu C.He H.W.Chen J.F.Nie C.Q.Liu;C.He;H.W.Chen;J.F.Nie

作者机构：International Joint Laboratory for Light Alloys(Ministry of Education)College of Materials Science and EngineeringChongqing UniversityChongqing400044China Department of Materials Science and EngineeringMonash UniversityVictoria3800Australia Electron Microscopy CenterChongqing UniversityChongqing400044PR China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2020年第42卷第10期

页      面：230-240页

核心收录：

学科分类：0817[工学-化学工程与技术] 0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：National Natural Science Foundation of China(51771036,51131009 and 51421001) National Key Research and Development Program of China(2016YFB0700402) Graduate Student Research Innovation Project of Chongqing University support of the“111”Project(B16007)by the Ministry of Education and the State Administration of Foreign Experts Affairs of China supported by the Australian Research Council 

主　　题：Heterogeneous precipitation HAADF-STEM Shockley partial dislocation Frank partial dislocation Dislocation reaction 

摘      要：In this work,we have systematically investigated precipitation ofβ’-Mg3Sn phase on intrinsic stacking faults I1 and I2 in a Mg-9.8 wt%Sn alloy using aberration-corrected scanning transmission electron *** observed I1 faults are generated by the dissociation of c+a perfect dislocations and bounded by Frank partial dislocations having a Shockley *** ofβ’on I1 involves a shear of 1/3α,similar to its formation directly from theα-Mg ***β’phase often nucleates at one end of an I1 fault due to the interaction between shear strain fields ofβ’and the Shockley component of the Frank partial at that end,and subsequently grows towards the other end of the *** theβ’reaches to the other end,the Shockley partial bounding the lengthening end of theβ’reacts with the Frank partial bounding the fault,generating an a perfect dislocation that can glide away from the precipitate and the *** observed I2 faults are generated by the dissociation of a perfect dislocations and bounded by Shockley *** ofβ’on I2 does not need a shear of 1/3α,since the pre-existing I2 fault already provides an ABCA four-layer structure ofβ’.Thickening of theβ’that has already formed on the I2 involves the successive occurrence of three crystallographically equivalent shears of 1/3αon every second(0002)αplane of theα-Mg *** this thickening mechanism is similar to that of theβ’formed directly from theα-Mg matrix,an a perfect dislocation will be produced when theβ’is thickened to eight layers,and it can again glide away from the precipitate and the fault.