摘要
以近期建立起来的非平衡晶界偏聚模型为基础,介绍了非平衡晶界偏聚动力学理论.该理论引入了临界时间概念,将等温过程中溶质原子的非平衡晶界偏聚动力学过程分为偏聚过程与反偏聚过程.对等温过程中的临界时间公式进行了理论分析与实验验证,证实了临界时间公式用于预测溶质原子非平衡晶界偏聚量达到极大值的恒温时间的准确性.并且研究了等温过程中的临界时间与连续冷却过程中的有效时间之间的区别和联系,将连续冷却过程等效为恒温过程,利用恒温动力学方程计算连续冷却过程中溶质原子的偏聚量.
The theory of nonequilibrium grainboundary segregation kinetics based on the nonequilibrium grainboundary segregation model is introduced in this paper. A critical time is defined to be the most characteristic aspect of nonequilibrium segregation. It divides the nonequilibrium grainboundary segregation into segregation process and desegregation process. Theory analysis and experiment had been done for confirming the veracity of the critical time formula used for forecasting the holding time at which the segregation concentration reaches a maximum. The critical time under isothermal condition and its differences as well as relationships to the effective time in continuous cooling process are studied emphatically. Nonequilibrium grainboundary segregation kinetics equation under isothermal condition can be used for continuous cooling process by comparing the critical time with the effective time.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
2002年第6期101-105,共5页
Journal of Harbin Engineering University
基金
国防科工委基础研究基金资助项目(J1600E001)
黑龙江省自然科学基金资助项目.
关键词
非平衡晶界偏聚
临界时间
反偏聚
有效时间
non-equilibrium grain-boundary segregation
critical time
desegregation
effective time
