Ni₇₅Al_xCr_25-x合金时效组织演变行为微观相场模拟

来源期刊：有色金属2011年第1期

论文作者：张济祥 陈铮 来庆波 赵彦

文章页码：38 - 42

关键词：金属材料； Ni₇₅Al_xCr_25-x合金； 微观相场法； 体积分数； 原子图像

Key words：metal material； Ni₇₅Al_xCr_25-x alloys； microscopic phase-field； volume fraction； atomic figure

摘    要：利用三元微观相场动力学模型,结合原子图像、有序相颗粒半径和和体积分数等手段模拟研究不同浓度的Ni₇₅Al_xCr_25-x合金973K下的时效组织演变行为。结果表明,x=6,8,10三种Ni₇₅Al_xCr_25-x合金时效过程中均析出DO₂₂和L1₂两种有序相。随着Al含量的增加,L1₂相颗粒的尺寸增大,体积分数增加,相应的DO₂₂相颗粒的尺寸减小,体积分数减少。无论DO₂₂相还是L1₂相,在考虑弹性畸变能的影响后,有序相颗粒平均半径的立方与时间之间仅仅在粗化初期的某一阶段,近似的呈线性关系。整体上来看,不满足LSW粗化理论。

Abstract: The microstructure evolution of Ni₇₅Al_xCr_25-x alloy aging at 973K is simulated with ternary microscopic phase-field and investigated by means of atomic pictures,particle radius and volume fraction.The results show that DO₂₂ and L1₂ ordered phases are formed during the aging of Ni₇₅Al_xCr_25-x alloy for x=6,8 and 10,respectively.The particle size and volume fraction of L1₂ phase are increased,correspondingly,the particle size and volume fraction of DO₂₂ phase are decreased with the increase of Al content.Considering the effects of elastic strain energy,on the whole,the coarsening behavior of both DO₂₂ phase and L1₂ phase do not follow the time-law predictions of LSW theory of diffusion controlled growth,and there exists linear relation between the particle radius and time only at the early stage of precipitation.