Fracture characteristics in micron molybdenum wires under cyclic torsion loading  

作　　者：Yiqun Hu Suhang Ding Yuhang Zhang Jianfei Xu Hongjian Zhou Wenwang Wu Re Xia 

机构地区：[1]Key Laboratory of Hydraulic Machinery Transients(Wuhan University),Ministry of Education,Wuhan 430072,China [2]School of Mechanical&Electrical Engineering,Wuhan Institute of Technology,Wuhan 430205,China [3]Department of Engineering Mechanics,School of Naval Architecture,Ocean&Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Journal of Materials Science & Technology》2024年第24期220-232,共13页材料科学技术(英文版)

基　　金：financially supported by the National Natural Science Foundation of China(Grant No.12072241).

摘　　要：Micron-scale molybdenum(Mo)wires are vital in numerous technological applications,including micro-electromechanical systems and nanodevices.Understanding their mechanical behavior under cyclic torsion loading is critical in designing reliable and durable components.This work investigates the mechanical behavior and fracture characteristics of micron Mo wires under various torsional loading conditions,including monotonic,symmetric,and asymmetric cyclic torsion.The results reveal that the fractures observed in Mo wires exhibit a relatively planar characteristic with noticeable clockwise river-patterned cleavage steps under monotonic torsion,mirroring the direction of the torsional stress applied during the experiment.In terms of symmetric cyclic torsion,it is notable that cyclic softening becomes increasingly pronounced as the increase of strain amplitude.The fractures exhibit distinctive stratification,characterized by the longitudinal cracks propagating radially.When the unloading strain is less than the loaded strain,the extent of the strain hysteresis effect amplifies with an increase in unloading strain.And the observed fracture characteristics are consistent with those under monotonic torsion.Differently,when the loading strain equals the unloading strain,a distinctive fracture pattern emerges in the Mo wire,characterized by a"peak"shape.This research provides valuable insights for optimizing the mechanical reliability of micron wires in microscale and nanoscale applications.

关 键 词：Micro-torsion Molybdenum wire Cyclic deformation Fracture characteristics Cyclic softening 

分 类 号：TG6[金属学及工艺—金属切削加工及机床]