A unified model of grain-boundary segregation kinetics

作者：Wu, Jian^*; Song, Shenhua

来源：Journal of Applied Physics, 2011, 110(6): 063531.

DOI：10.1063/1.3632967

• LOW-ALLOY STEEL
• APPLIED TENSILE-STRESS
• CRITICAL COOLING RATE
• CRITICAL TIME
• TEMPER EMBRITTLEMENT
• STAINLESS-STEEL
• PHOSPHORUS
• VACANCY
• DIFFUSION
• COMPLEXES

A unified model of grain-boundary segregation kinetics is established, which can simulate the equilibrium and non-equilibrium grain-boundary segregation kinetics during isothermal ageing. The results of model fittings/predictions are in a good consistence with those of the experiments. Values of several important parameters, such as vacancy formation energy, vacancy migration energy, and complex migration energy derived by model fittings, show a reasonably good agreement with those in the references. Relationship between the equilibrium and non-equilibrium grain-boundary segregation mechanisms is discussed in detail. The segregation peak/depletion trough observed in the non-equilibrium segregation kinetics may be ascribed to the vacancy flux. The equilibrium segregation kinetics is considered as a special case in non-equilibrium segregation kinetics with the zero vacancy flux. Both the equilibrium and non-equilibrium segregation kinetics are believed to be dominated by vacancy-solute complex flux. The proposed unified model can be a significant progress in grain-boundary segregation theory, with applications in guiding the design of materials.

• 出版日期2011-9-15
• 单位哈尔滨工业大学深圳研究生院; 清华大学深圳研究生院