报告题目：         

Stress-assisted dissolution of 45S5 glass

报告人:                     Fuqian Yang教授

Chemical and Materials Engineering Department, University of Kentucky, Lexington, USA

时间：2016年6月1日(周三)  10: 00

地点：中国科学院力学研究所1号楼小礼堂内报告厅

报告摘要：

The stress-assisted dissolution of material in an aqueous solution is a thermal activation process. The rate theory used to describe the stress-assisted dissolution of material is briefly reviewed, which reflects both physical and chemical processes. The stresses-assisted dissolution of the 45S5 bioglass was demonstrated by studying the growth behavior of radial cracks in phosphate buffer solution. Using microindentation technique, localized residual stresses were created in 45S5 bioglass. Dissolution initiated from the location with the highest tensile residual stresses such as the cracks especially the crack tips. The damaged indent center dissolved much faster than other regions. The region between cracks with compressive residual stresses dissolved more slowly than stress free region. A linear relation between indentation load and the ratio of the change in crack length to the square root of time was established, which was supported by experimental results.

报告人简介：

Dr. Fuqian Yang received his B.S. in Engineering Physics from Tsinghua University, M.S. in Mechanical Engineering and Ph.D. in Materials Science and Engineering from the University of Rochester. He is a full professor in the Department of Chemical and Materials Engineering at the University of Kentucky. Dr. Yang’s research focuses on electrical-chemical-mechanical behavior of advanced materials, including creep behavior of materials, adhesive deformation of materials, electromechanical interaction of materials, whisker growth, and stress-diffusion interaction in lithium-ion batteries. He has proposed the concept of grain boundary fluid in analyzing the creep behavior of crystalline metals and developed the techniques of electrical impression test, electric indentation, and evaporation-induced surface structures on polymer films. Dr. Yang is a member of editorial board for Materials Science and Engineering A, Materials and Metallurgical Transaction A, Smart Grid and Renewable Energy and Annals of Materials Science & Engineering. He and Professor J.C.M. Li of the University of Rochester recently co-edited a book “Micro and Nano Mechanical Testing of Materials and Devices”, which was published by Springer in 2008.