Theoretical progress in non-equilibrium grain-boundary segregation (II):Micro-mechanism of grain boundary anelastic relaxation and its analytical formula  

作　　者：XU TingDong WANG Kai SONG ShenHua 

机构地区：[1]Central Iron and Steel Research Institute,Superalloy Department,Beijing 100081,China [2]Department of Materials Science and Engineering,Shenzhen Graduate School,Harbin Institute of Technology,Shenzhen 518055,China

出　　处：《Science China(Technological Sciences)》2009年第6期1679-1687,共9页中国科学（技术科学英文版）

基　　金：Supported by the National Natural Science Foundation of China(Grant No.50771036)

摘　　要：Finding the internal-friction peak of grain boundary anelastic relaxation was one of the important breakthroughs in the study of internal friction in the last century.But the micro-mechanism of grain boundary anelastic relaxations is still obscure.Based on the observations of the grain boundary seg-regation or depletion of solute induced by an applied stress,the following micro-mechanism was suggested:grain-boundaries will work as sources to emit vacancies when a compressive stress is exerted on them and as sinks to absorb vacancies when a tensile stress is exerted,inducing grain-boundary depletion or segregation of solute,respectively.The equations of vacancy and solute con-centrations at grain boundaries were established under the equilibrium of grain-boundary anelastic relaxation.With these the kinetic equations were established for grain boundary segregation and depletion during the grain boundary relaxation progress.Finding the internal-friction peak of grain boundary anelastic relaxation was one of the important breakthroughs in the study of internal friction in the last century. But the micro-mechanism of grain boundary anelastic relaxations is still obscure. Based on the observations of the grain boundary segregation or depletion of solute induced by an applied stress, the following micro-mechanism was suggested: grain-boundaries will work as sources to emit vacancies when a compressive stress is exerted on them and as sinks to absorb vacancies when a tensile stress is exerted, inducing grain-boundary depletion or segregation of solute, respectively. The equations of vacancy and solute concentrations at grain boundaries were established under the equilibrium of grain-boundary anelastic relaxation. With these the kinetic equations were established for grain boundary segregation and depletion during the grain boundary relaxation progress.

关 键 词：grain boundary SEGREGATION anelastic RELAXATION kinetics 

分 类 号：TB302[一般工业技术—材料科学与工程]