Orientation-dependent ductility and deformation mechanisms in body-centered cubic molybdenum nanocrystals  

作　　者：Huayu Peng Yuxuan Hou He Zheng Ligong Zhao Ying Zhang Weiwei Meng Ting Liu Peili Zhao Shuangfeng Jia Jianbo Wang 

机构地区：[1]School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China [2]Suzhou Institute of Wuhan University, Suzhou, Jiangsu 215123, China [3]Wuhan University Shenzhen Research Institute, Shenzhen, Guangdong 518057, China [4]Core Facility of Wuhan University, Wuhan 430072, China

出　　处：《Journal of Materials Science & Technology》2023年第23期107-113,共7页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foun-dation of China(No.52071237,12074290,51871169,52101021,and 12104345);the Natural Science Foundation of Jiangsu Province(No.BK20191187);the Young Top-notch Talent Cultivation Program of Hubei Province,the Science and Technology Program of Shenzhen(No.JCYJ20190808150407522);the China Postdoctoral Science Foundation(No.2019M652685).

摘　　要：The knowledge regarding anisotropic mechanical behaviors in nanoscale body-centered cubic (bcc) metals remains obscure. Herein, we report the orientation-dependent ductility in bcc Mo nanocrystals (NCs), which exhibit poor ductility along [110] direction but possess relatively better ductility along the [001] and [112] orientations. The origin of different deformability can be traced down to the distinct deformation mechanisms: the unexpected crack nucleation and propagation induce premature fractures in [110]-oriented NCs;in contrast, deformation twinning could contribute to the enhanced ductility in [001]-oriented NCs;interestingly, we find the activation of multiple dislocation slips in [112]-oriented NCs with the highest ductility. Further molecular dynamics simulations provide deeper insights into the defect dynamics that are closely interlinked with experimental observations. Our findings advance the basic understanding of orientation-dependent mechanical properties and help to guide endeavors to architecture the microstructures of bcc metals with enhanced ductility.

关 键 词：In-situ tension test DUCTILITY CRACK Deformation twinning Dislocation slips Mo nanocrystals 

分 类 号：TG146.23[一般工业技术—材料科学与工程]