报告人：李旺辉 研究员（新加坡科技研究局 高性能计算研究院）

报告内容：

Understanding the mechanical behavior of materials under extreme conditions has become increasingly important in recent years, owing to a growing demand for high-strength and high-hardness materials that can serve as critical structural components under extreme conditions, including high-pressure, ultralow and ultrahigh temperature, and high strain rates, among others. In this talk, I will first briefly introduce my work on molecular dynamic simulations of shock response of different materials such as silicon carbide, diamond, metals and alloys, then the main focus will be on high entropy alloy (HEA).HEA, as a new class of materials, has gained tremendous attention since it was first proposed 20 years ago. The unique characteristics of HEAs lead to excellent mechanical and chemical properties. HEAs are even able to maintain high strength, ductility, and high damage tolerance across a wide temperature range. These advantages make HEAs promising structural materials for aerospace and civil transport, defense, and other engineering applications. Since the dynamic characteristics and the mechanisms of damage and deformation are important in assessing the reliability of structural materials, it is necessary to have an in-depth understanding of their responses to dynamic loading. In this talk, three scientific problems will be discussed: 1) Anisotropy of deformation mechanisms in shocked singlecrystal CoCrFeMnNi HEA; 2) Chemical Short-Range Ordering effect on the strength and ductility of CoCrFeMnNi HEA under dynamic loading; 3) Hall-Petch to Inverse Hall-Petch transition of flow stress in nanocrystalline CoCrFeMnNi HEAs subjected to shock loading at high strain rates.

报告人简介：

李旺辉，新加坡科技研究局高性能计算研究院研究科学家/研究员，于2012获南昌大学土木工程专业学士学位， 2018年获华南理工大学固体力学专业博士学位， 2017-2018在美国洛斯阿拉莫斯国家实验室博士联合培养，随后入职华南理工大学从事博士后研究， 2022年入职新加坡科技研究局高性能计算研究院。长期从事凝聚态物质的冲击压缩和材料动力学的微纳尺度计算模拟和理论分析，聚焦高压高应变率、高温和超低温等极端条件下材料的变形、损伤和破坏行为，以及材料的塑性和相变机制等，力图构建材料微纳结构-材料性能-动加载条件之间的相互关系，为理解材料在极端条件下的物性和相关先进材料的微纳结构设计提供科学参考。曾主持国家自然科学基金-青年基金项目、中央高校基本科研业务费-面上项目以及横向课题等，曾入选2019年全国博士后创新人才支持计划，广东省力学学会优秀博士论文等，《高压物理学报》青年编委，在Acta Materialia, International Journal of Plasticity, Scripta Materialia, International Journal of Mechanical Sciences等力学和材料领域的著名期刊发表学术论文30余篇。

主持人：陈默涵 研究员（北京大学应用物理与技术研究中心）

时  间：2024年12月12日（周四）12:00

地  点：北京大学工学院1号楼210会议室