报告题目：Confined Volume Enabled Unusual Plasticity in Secondary Phase Strengthened Al Alloys
报告内容简介：Nanoscale dual-phase alloys composed of alternate metal (soft) and intermetallic or covalently bonded (hard) strengthening phase exhibit high strength, high strain hardening rate and measurable plasticity at ambient and elevated temperatures. Here we report unusual plasticity carriers in intermetallic Al2Cu and covalently bonded Silicon in Al-Si and Al-Cu alloys based on multiscale experiments and modeling. Plastic deformation commences in soft phase associated with the nucleation and gliding of dislocations. Hard strengthening units act as strong barriers for the motion of dislocations in soft phase. As a result, the propagation of dislocations is confined in the soft phase, resulting in dislocation deposition and accumulation in the soft/hard phases interfaces. Consequently, strain hardening develops in the soft phase associated with back stress due to the plastic deformation incompatibility between adjacent phases. Particularly the geometric compatibility between adjacent phases enables the hard phase to plastically deform via unusual slip mechanisms. The high stress developed in nanostructures triggers unusual shear in hard phase (plastic co-deformation) or instability such as bending and kinking (instability) and cracking in hard phase (failure). Cracks in hard phase initiate by the increased tensile stress due to loading transfer in tension test or bending induced tensile stress in compression test. These mechanical behaviors are strongly related to the plastic deformability and the characteristic dimension of the hard phase.
报告人简介(中文)：王健，自2015年8月起任内布拉斯加州林肯大学材料与机械工程系真实亲子乱子伦漫画完整版真实亲子乱子伦漫画完整版教授教授，在洛斯阿拉莫斯国家实验室（LANL）担任技术人员9年。于2006年获得美国纽约州特洛伊伦斯勒理工学院的博士学位。研究重点是利用多尺度理论，建模和实验方法和技术，定量探索结构和纳米结构材料的结构—性能关系。曾获得LANL杰出博士后表现奖（2009），LDRD /早期职业生涯奖（2011），两项LDRD-ER奖（2013年），TMS MPMD年轻领袖奖（2013年），国际塑性青年研究奖（2015年）和 TMS BRIMACOMBE 冶金学家奖。曾任“International Journal of Plasticity”（2015~），“Scientific Reports”（2016~）等编委。发表了200多篇同行评议论文（引用量20000多篇，H指数82多篇，被选为材料科学最热门文章25篇，期刊封面9篇），发表了100多篇邀请/主题演讲。
报告人简介(英文)：Dr. Jian Wang is Wilmer J. and Sally L. Hergenrader Presidential Chair of Mechanical and Materials Engineering at the University of Nebraska-Lincoln since 2015. He received his PhD from Rensselaer Polytechnic Institute in 2006 and worked as technical staff member at Los Alamos National Laboratory (LANL) until 2015. His research focuses on quantitatively exploring the structure-properties relations of materials using multi-scale theory, modeling and experimental methods and techniques. He was awarded the LANL Distinguished Postdoctoral Performance Award (2009), the LDRD/Early Career Award (2011), TMS MPMD Young Leader Award (2013), International Plasticity Young Research Award (2015), Materials Today Rising Star Award in the category of Materials Genome Innovation (2018), TMS MPMD Distinguished Scientist Award (2022) and TMS BRIMACOMBE MEDALIST Award (2023). He is Fellow of ASME and Fellow of ASM International. He served as Editorial Board of International Journal of Plasticity (2015~), Materials Research Letters (2016~), and others. He has published more than ~300 peer-reviewed papers (> 20,000 citations and H-index = 82; 9 papers featured as Journal cover) and delivered 150+ invited/keynote lectures.
报告人单位(英文)：University of Nebraska-Lincoln