简介：刘哲，现任澳大利亚墨尔本大学机械工程系副教授。2002年和2006年分别毕业于清华大学力学系和美国西北大学材料工程系，获得力学和材料科学两个博士学位。历任美国再生能源国家实验室博士后研究员，澳大利亚蒙纳什大学讲师和高级讲师。主要研究领域为基于第一原理计算的合金性能设计，纳米材料的力学/物理/化学学科交叉的前沿科学问题。迄今为止，刘哲博士在Science，Nat. Nanotechnol.，Nat. Commun.，PRL，JACS，Adv. Mater.等国际期刊上发表学术论文80余篇，其中第一作者或通讯作者论文46篇，2篇论文获评ESI高被引论文。曾获全国优秀百篇博士论文奖，教育部自然科学一等奖（第三完成人）和国家自然科学二等奖（第二完成人）。
【报告题目】First-principles computation aided design for metallic alloys
时间: 10:10-12:00 am, Sep.18th,2017
摘要：The physical and mechanical properties of metallic alloys are determined by their hierarchical structures. Design of the hierarchical structures in materials requires a hierarchy of models. Integrated computational materials engineering (ICME) is a promising and powerful approach to design products, the materials that comprise them, and their associated materials processing methods by linking materials models at multiple length scales. In this presentation, I will introduce some examples of metallic alloy systems to show the essential role of first-principles computations in ICME. First, first-principles calculations were employed to reveal physical mechanisms of the anomalous solute segregation to fully coherent twin boundaries in MgGdZn alloys observed in experiments. Mechanical strengthening effect arising from the segregation was predicted and then confirmed in experiments. The obtained in-depth understanding indicates a new design concept for metallic alloys. Second, first-principles computations were used to determine fundamental material properties of the metastable nano-precipitates in FeCu alloy that are not attainable by either experiments or other computational methods. The obtained results are essential to develop reliable mechanical strengthening models for alloy design. Third, we proposed a method based on first-principles calculations to accurately determine free energy of different phases in Al-Ti,Zr,Hf alloys. Compared with conventional experimental methods, our method provides an efficient way to determine alloy phase diagrams. All the cases demonstrate that the first-principles study is not only an effective way to obtain in-depth understanding and propose new concepts for alloy design, but also an efficient tool to determine essential material property parameters for upper length scale models in ICME design.