Numerical Analysis of Observations on Diffusion Induced Recrystallization in the Ni(Cu) System using A Kinetic Model
Numerical Analysis of Observations on Diffusion Induced Recrystallization in the Ni(Cu) System using A Kinetic Model
复制标题
使用动力学模型对 Ni(Cu) 系统中扩散诱导再结晶的观察结果进行数值分析
DOI：
10.2320/matertrans.42.1763
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发表时间：
2001
影响因子：
1.2
通讯作者：
M. Kajihara
中科院分区：
文献类型：
--
作者：
Y. Yamamoto;M. Kajihara
考虑溶质体积扩散摩擦力对驱动力的影响，提出了溶质B原子扩散成纯a金属或二元a -B合金的扩散诱导再结晶（DIR）动力学模型。能量平衡模型[M]；Kajihara和W. Gust: Scr。Mater. 38(1998) 1621]结合了柱状几何和边界扩散模型[C]。Li和M. Hillert：金属学报，29 (1981)1949 [j]。Kawanami et al.: ISIJ Int. 37(1997) 921]，以数学方式描述由DIR形成的细晶区（DIR区）的生长速率作为反应时间的函数。Ni（Cu）体系中的DIR是由Kawanami等人实验观察到的。Kawanami等人：脱线。反式。， JIM 39(1998) 218]在923和1023 K。新模型已被用来从理论上分析他们的观测结果。根据观察，随着反应时间的增加，移动边界的迁移速率v逐渐减小。然而，在实验反应时间Δt = 1s的小时间间隔内，迁移速率v的下降可以忽略不计。因此，为了简化分析，假设v的值在每个时间步长都是恒定的，at = 1s。以运动边界的迁移率M为拟合参数，采用数值计算方法计算了反应时间对DIR区域厚度的影响。计算得出在923和1023 K时M = 3.73 × 10 -17和1.51 × 10 -15 M 4 / j，因此M = M 0 exp(-Q M /RT) M = 1.03 M 4 / j和Q M = 290 kJ/mol。迁移率的温度依赖性表明，晶界迁移可能受溶质阻力效应控制，其中溶质在移动边界前未变换基体中沿移动方向的体积扩散起着最重要的作用。
Considering the effect of the friction force due to volume diffusion of a solute on the driving force, a new kinetic model has been proposed for diffusion induced recrystallization (DIR) in the A(B) system in which solute B atoms diffuse into a pure A metal or a binary A-B alloy. The energy balance model [M. Kajihara and W. Gust: Scr. Mater. 38 (1998) 1621] has been combined with the columnar geometry and boundary diffusion model [C. Li and M. Hillert: Acta Metall. 29 (1981) 1949] and the extended model [Y. Kawanami et al.: ISIJ Int. 37 (1997) 921] in order to describe mathematically the growth rate of the fine grain region (DIR region) formed by DIR as a function of the reaction time. DIR in the Ni(Cu) system was experimentally observed by Kawanami et al. [Y. Kawanami et al.: Mater. Trans., JIM 39 (1998) 218] at 923 and 1023 K. The new model has been utilized to analyze their observations theoretically. According to the observations, the migration rate v of the moving boundary gradually decreases with increasing reaction time. However, the decrease in the migration rate v is negligible during a small time interval of Δt = 1 s at the experimental reaction times. Thus, the value of v was assumed to be constant at each time step with At = 1 s in order to simplify the analysis. Using the mobility M of the moving boundary as the fitting parameter, the thickness of the DIR region was calculated as a function of the reaction time by a numerical technique. The calculation gives values of M = 3.73 x 10 -17 and 1.51 x 10 -15 m 4 /Js at 923 and 1023 K, respectively, and thus M 0 = 1.03 m 4 /Js and Q M = 290 kJ/mol for M = M 0 exp(-Q M /RT). The temperature dependence of the mobility indicates that the grain boundary migration may be governed by the solute drag effect for which the volume diffusion of the solute along the moving direction in the untransformed matrix ahead of the moving boundary has the most important role.