报告题目：Microstructure, texture and strength evolution during severe plastic deformation of CrMnFeCoNi high-entropy alloy

报告内容简介：An equiatomic high-entropy alloy CrMnFeCoNi has been severely deformed by high pressure torsion at room and liquid nitrogen temperature (RT and LNT). The microstructure and texture has been analyzed by X-ray diffraction (X-ray line profile analysis and X-ray microdiffraction, respectively). It is shown that at a certain shear strain a steady state domain/grain size in the nanometer range and a dislocation density of the order of 1016 m-2 is reached, while the twin density at RT goes over a maximum at this strain. At LNT above a certain hydrostatic pressure HPT deformation is accompanied by phase transformation from face-centred cubic (fcc) to hexagonal (hcp). The amount of hcp phase increases with increasing pressure. The texture developed is typical for sheared fcc metals with a weak brass-type shear component dominating. Moreover, microhardness tests have been applied. Analysis of the strength suggests a Taylor-type hardening. The results will be discussed with regard to the mechanisms of deformation, including dislocation slip, twinning, martensitic transformation and grain boundary sliding.

报告人姓名：Werner Skrotzki

报告人简介：Werner Skrotzki教授为德累斯顿工业大学固体及材料物理研究所教授，长期从事金属、合金、超导和形状记忆合金以及采用扫描电镜EBSD、同步辐射和透射电镜对材料的织构和微观结构进行研究。他是DFG材料领域咨询专家、SFB项目的首席科学家。已在 Nature Mater.、Acta Mater.、 Scripta Mater.、Appl. Phys. Lett.等期刊发表学术论文300余篇。

报告人单位：Institute of Solid State and Materials Physics, TU Dresden

报告时间：2019-07-16 09:30

报告地点：材料学院 520报告厅

主办单位：上海大学材料学院

联系人：操光辉