2015年3月11日下午3:00，由中南大学材料学院青年科协联合院研究生会举办的青年学术沙龙第118场在特冶楼229学术活动室顺利举行。

本次学术沙龙的主讲人是我校2002级校友，法国国家科学研究院博士后研究员石章智博士，主题是“低施密特因子拉伸孪晶的变体选择”。报告会由江勇教授主持，有刘会群副教授等众多师生到场参加。        

报告主要内容为：{10-12}< -1011> extension twinning is an important deformation mode in Mg and its alloys. This twinning mode has a low critical resolved shear stress (CRSS) in pure Mg and Mg alloy AZ31, and can lead to substantial strain softening. In this report, a statistical analysis is conducted on the formation of {10-12} extension twin (ETW) variants with low Schmid factors (SFs), based on large data sets acquired by electron backscattering diffraction (EBSD) on a deformed Mg alloy AZ31. The majority of the low SF twins grow from grain boundaries, requiring shear accommodation in their neighboring crystals. A method is developed to determine the twin induced shear on 5 common deformation modes in Mg, including all the variants of these deformation modes. Statistical analysis reveals that the low SF twins require not only the most or more accommodation through several deformation modes with low critical resolved shear stresses (CRSSs), but also the least or less accommodation through several deformation modes with high CRSSs. This study shows that criteria considering only one deformation mode for accommodation, which are widely employed before, are limited for prediction of twin selection.       

报告人简介：

石章智，博士，法国国家科学研究院博士后研究员。2002-2006年本科毕业于中南大学金属材料工程专业。2011年博士毕业于清华大学材料科学与工程专业，导师为张文征教授。2011-2013年就职于北京钢铁研究总院结构材料研究所，任工程师。2013 -2015年为法国国家科学研究院微观组织及材料力学实验室从事博士后研究。主研课题《纯镁及镁合金的塑性》为法国国家科研署直接资助的法国最高级别基础研究项目。已在《Acta Mater》, 《Scripta Mater》等期刊发表论文10余篇。