文献类型：期刊文献

英文题名：The plasticity of single-crystal tin: insights from strain rate and deformation gradient under micro-mechanical experiments

作者：Yan, Yabin[1,2];Wan, Shijia[1,2];Ikemoto, Shotaro[3];Ito, Shota[3];Sugisaka, Kota[3];Zhang, Ziqin[1,2];Sumigawa, Takashi[3];Xuan, Fu-Zhen[1,2];Kitamura, Takayuki[3]

机构：[1]East China Univ Sci & Technol, Shanghai Key Lab Intelligent Sensing & Detect Tech, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[3]Kyoto Univ, Grad Sch Energy Sci, Sakyo Ku, Kyoto 6068501, Japan

年份：2026

卷号：316

外文期刊名：ACTA MATERIALIA

收录：;EI(收录号：20262620991694);WOS:【SCI-EXPANDED(收录号:WOS:001811075000001)】；

基金：Y. Yan thanks the support of National Natural Science Foundation of China (Grant Nos. 52275149 and U2468210) . T. Sumigawa thanks the support of JST CREST (Grant No. JPMJCR2092) , JSPS KAKENHI (Grant Nos. JP25KJ1508, JP24H00283, and JP24K21575) . F.Z. Xuan thanks the support of the Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of China (JYB2025XDXM404) .

语种：英文

外文关键词：beta-Sn; Strain rate sensitivity; Strain gradient; Microscale plasticity; In situ testing

摘要：The plastic deformation mechanisms of low-melting-point metals with low-symmetry structures at the microscale remain poorly understood. This study systematically investigates the plastic behavior and strain gradient effects of single-crystal beta-Sn under different strain rates through in situ SEM micro-tensile and micro-cantilever bending experiments. The results show that beta-Sn exhibits strong orientation dependence, with the (101)[-101] slip system activated under both loading modes. Crucially, the deformation mechanisms are sensitive to both strain rate and loading mode. At high strain rates, deformation is dominated by dislocation slip. At low strain rates, tensile specimens exhibit pronounced creep damage, whereas such damage is markedly suppressed in bending specimens due to the steep stress gradient and surface effects. Significant strengthening is observed under bending, attributed to the accumulation of geometrically necessary dislocations (GNDs). Quantitative analysis of surface slip steps reveals that the back stress from dislocation pile-ups scales with the square of the step height. The strain rate sensitivity parameter m (0.043-0.046) and the activation volume confirm a dynamic transition from diffusion-assisted climb at low rates to thermally activated slip at high rates. The microscale plastic behavior of beta-Sn lies between that of FCC and BCC metals, resulting from the combined effects of its BCT crystal structure anisotropy and low melting point. This study provides new theoretical insights into the interaction between diffusion-controlled damage, gradient-induced hardening, and loading-dependent stress distributions in the microscale plasticity of low-melting-point metals.