A New Alloy Design Method utilizing Diffusion Induced Recrystallization

用Cu/Cu合金对Fe（Cu）系扩散诱导再结晶进行了实验研究。（Fe-4.8Cu）/Cu扩散偶，以发展一种新的合金设计方法（Fe-4.8Cu）/Cu扩散偶由纯铜单晶和Fe-4.8Cu多晶试样组成，在300到86400 s之间的不同时间内，在1323 K下发生了变化。在此退火温度下，Fe-Cu相中从扩散偶界面开始出现晶界，并根据关系l=1.6（t/t_0）^随着退火时间的增加而生长<0.29>，其中l是晶界区的厚度，单位为μ m，t是退火时间，单位为s，t_0是单位时间（1 s）。另一方面，Fe-Cu相的厚度w随着退火时间的增加而减小，其关系式为w/w_0=1-5.0*10^<-5>*（t/t_0）^<0.5>，其中w_0为Fe-Cu相的初始厚度。因此，在退火56 h后，Fe-Cu相将完全被Fe-Cu相占据。该模型给出了晶界移动驱动力与晶界移动速率之间的定量关系。对于分析，铜的晶界扩散沿着晶界的扩散区的速度控制过程和Fe-Cu相是理想的结晶。在本实验条件下，Fe-Cu相的相变动力学方程为l=1.04（t/t_0）^&lt;1/3&gt;。分析定量地解释了观察结果。

Diffusion induced recrystallization (DIR) in the Fe (Cu) system was experimentally studied using Cu/ (Fe-4.8Cu) /Cu diffusion couples in order to develop a new alloy design method based on a fast diffusion phenomenon duc to DIR.Cu/ (Fe-4.8Cu) /Cu diffusion couples, which consist of pure copper single crystals and an Fe-4.8Cu polycrystalline specimen, were anecaled at 1323K for various times between 300 and 86400s. At this annealing temperature, DIR occurs in the Fe-Cu phase from the interface of the diffusion couple and grows with increasing annealing time according to the relation l=1.6 (t/t_0) ^<0.29>, where l is the thickness of the DIR region in mum, t the annealing time in s and t_0 the unit time (1s). On the other hand, the thickness w of the Fe-Cu phase decreases with increasing annealing time according to the relation w/w_0=1-5.0*10^<-5>* (t/t_0) ^<0.5>, where w_0 stands for the initial thickness of the Fe-Cu phase. Thus, the Fe-Cu phase will be completely occupied with DIR regions at an annealing time of 56h.The observations were numerically analyzed utilizing a energy balance model proposed by one of the present authors. This model gives a quantitative relationship between the driving force for DIR and the migration rate of the moving grain boundary. For the analysis, the grain boundary diffusion of copper along the grain boundaries of DIR regions is the rate controlling process and the Fe-Cu phase is thermodynamically ideal. The equation l=1.04 (t/t_0) ^<1/3> has been obtained to describe the kinetics of DIR in the Fe-Cu phase under the present experimental conditions. The analysis quantitatively accounts for the observations.