报告题目：Dislocation Engineering: A Promising Alloy Design Strategy
地点：浙江大学玉泉校区曹光彪科技大楼远望庐
时间：2018年12月12日（周三）上午10:00~11:00
邀请人：刘嘉斌，余倩
黄明欣博士简介
黄明欣博士
香港大学机械工程系
副教授（终身教职，tenured）、博士生导师、副系主任
黄明欣博士分别于2002年和2004年从上海交通大学获得工程力学学士学位和固体力学硕士学位，于2008年从荷兰代尔夫特理工大学 (TU Delft)获得材料科学的博士学位。在博士毕业之后，他受聘于全球最大钢铁企业安赛乐米塔尔在法国的全球研发中心从事汽车钢的研发工作。于2010年加入香港大学机械工程系，并于2016年晋升为副教授并获得终身教职（tenured）。
黄明欣博士目前在香港大学独立带领一个研究课题组，主要从事：(1)金属材料强韧化及相变研究;(2)汽车轻量化超高强钢研发。研究内容包含试验研究、理论建模和三维模拟，同时兼顾基础研究与应用研究。与美国通用汽车、法国安赛乐米塔尔集团、鞍钢、宝钢等企业紧密合作。以第一作者或者通讯作者在Science 、Acta Materialia、JMPS、International Journal of Plasticity等期刊发表论文90余篇，H-index 23 (Google Scholar)。担任Materials Research Letters、Metallurgical and Materials Transactions A 、Materials Science and Technology、Journal of Materials Science and Technology、JOM期刊编委 （Member of Editorial Board）。中国金属学会材料分会理事；中国材料学会青年工作委员会理事；中国机械工程学会热处理学会青年工作委员会理事；担任Science、Nature Communication、Acta Materialia等20多本SCI杂志审稿人。黄明欣博士在2018年获得美国TechConnect全球创新奖、2017年中国科技新锐人物、2017年港大工学院卓越知识交流奖、2015、2016、2018 ACTA/Scripta Materialia杂志年度最佳审稿人
Dislocation Engineering: A Promising Alloy Design Strategy
The Materials Science community has spent tremendous efforts on developing ultrahigh-strength alloys with good ductility for lightweight structural application. However, improving the strength of alloys frequently results in a reduction in ductility, which is known as the strength-ductility trade-off in metallic materials. Current alloy design strategies for improving the ductility of ultrahigh-strength alloys mainly focus on the selection of alloy composition (atomic length scale) or manipulating ultrafine and nano-grained microstructure (grain length scale). The intermediate length scale between atomic and grain scales is the dislocation length scale. A new alloy design concept based on such dislocation length scale, namely alloy desgin by dislocation engineering, is illustrated in the present work. This dislocation engineering concept has been successfully substantiated by the design and fabrication of a deformed and partitioned (D&P) steel with a yield strength of 2.2 GPa and an uniform elongation of 16% [1]. In the D&P steel, high dislocation density can not only increase strength but also improve ductility. High dislocation density is mainly responsible for the improved yield strength through dislocation forest hardening, whilst the improved ductility is achieved by the glide of intensive mobile dislocations and well-controlled transformation-induced plasticity (TRIP) effect, both of which are governed by the high dislocation density resulting from warm rolling and martensitic transformation during cold rolling.
Reference
[1] B.B. He, B. Hu, H.W. Yen, G.J. Cheng, Z.K. Wang, H.W. Luo, M.X. Huang 2017 “High dislocation density induced large ductility in deformed and partitioned steels”, Science, 357, 1029
