德国马普钢铁学会研究所李志明博士学术报告
报告题目：
Metastable high-entropy alloys: design, structure and properties
报告人：
李志明（Zhiming Li）德国马普学会钢铁研究所（Max-Planck-Institut für Eisenforschung, Germany）
时间：
2018年05月23日上午10:00
地点：
上海交通大学（闵行校区）材料科学与工程学院，徐祖耀楼500号
联系人：
付立铭
报告人简介：
李志明博士系德国马普学会钢铁研究所高熵合金研究组负责人，目前主要从事新型多主元高熵合金的设计、加工、结构和性能研究。李志明博士于2014年获上海交通大学材料科学与工程专业博士学位，博士就读期间于美国加州大学戴维斯分校联合培养。李志明博士以第一兼通讯作者在Nature和Acta Materialia等主流学术期刊发表论文30余篇；在材料学主流学术会议上应邀主讲10余场学术报告；长期担任多种国际期刊的审稿人，已评审稿件160余篇。
摘要：
Title：Metastable high-entropy alloys: design, structure and properties
Zhiming Li，Max-Planck-Institut für Eisenforschung, Germany，Email：zhiming.li@mpie.de
The concept of high-entropy alloys (HEAs) has drawn great attention as it opens a new realm of compositional opportunities for designing novel materials with exceptional mechanical, physical and chemical properties. HEAs were originally proposed to contain multiple principal elements in near-equimolar ratios to stabilize single-phase solid solutions through maximizing configurational entropy. By overturning this original concept which targets for the formation of single-phase solid solution, we recently developed a novel class of HEAs with multiple compositionally equivalent high-entropy phases and transformation-induced plasticity. In this talk, I will first introduce this type of metastable HEAs by shedding light on the corresponding design principles and highlighting their superior strength-ductility combinations compared to the corresponding single-phase HEAs. Then I will present our recent findings on designing interstitially alloyed metastable HEAs which shows the joint activation of twinning and transformation induced plasticity upon mechanical loading. Owing to the multiple deformation mechanisms active, the novel interstitial HEA shows further improved strength-ductility combination.
Key references:
[1] Z. Li*, et al., Metastable high-entropy dual-phase alloys overcome the strength-ductility trade-off，Nature, 534 (2016) 227-230.
[2] Z. Li*, et al., A TRIP-assisted dual-phase high-entropy alloy: grain size and phase fraction effects on deformation behavior，Acta Mater., 131 (2017) 323-335.
[3] Z. Li*, et al., Ab initio assisted design of quinary dual-phase high-entropy alloys with transformation-induced plasticity，Acta Mater., 136 (2017) 262-270.
[4] Z. Li*, et al., Interstitial atoms enable joint twinning and transformation induced plasticity in strong and ductile high-entropy alloys，Sci. Rep., 7 (2017) 40704.
[5] Z. Li*, et al., Strong and ductile non-equiatomic high-entropy alloys: design, processing, microstructure, and mechanical properties，JOM, 69 (2017) 2099-2106.
