微观相场法研究铝合金界面错配应力的影响

来源期刊：有色金属2011年第1期

论文作者：马锐 王永欣 陈铮 苗树芳 苗海川 钟汉文

文章页码：33 - 37

关键词：金属材料； 铝合金； 微观相场法； 界面错配应力； 孕育期； 粗化速率

Key words：metal material； Al-based alloy； microscopic phase-field model； interfacial misfit stress； gestation period； coarsening rate

摘    要：用微观相场法模拟界面错配应力对铝合金沉淀孕育期、粗化速率及沉淀机制的影响。结果表明,在界面错配应力作用下,沉淀相由球状转变为椭片状及针状,与Al-Li合金中δ′相和Al-Li-Cu合金中T1相的实验结果相吻合。界面错配应力使沉淀孕育期增长,但随着错配应力的增大,孕育期缩短,仍比错配应力为零时的孕育期要长。粗化过程得到促进,沉淀相的粗化速率加快,错配应力越大,粗化速率越快。合金的沉淀机制为非经典形核长大,错配应力增大,这种特征增强。

Abstract: The effect of interfacial misfit stress on the precipitation gestation period,coarsening rate and precipitation mechanism of Al-based alloy is simulated based on microscopic phase-field model.The results show that with the effect of interfacial misfit stress,the precipitates are transformed from spherical shape to elliptical and pin shape,and this is consonant with the experiment results of δ′ phase in Al-Li alloy and T1 phase in Al-Li-Cu alloy.The gestation period is prolonged,but with the increase of misfit stress,the gestation period is shortened,it is still longer than that the misfit stress is zero.The coarsening process is accelerated,and the coarsening rate of precipitates is speeded,the bigger the interfacial misfit stress,the higher the coarsening rate.The precipitation mechanism is non-classical nucleation and growth,it is intensified with the increase of misfit stress.