论文部分内容阅读
为了获得合金静态再结晶前的变形晶粒组织,应用网格畸变模型与相场模型结合,生成变形合金再结晶前的初始晶粒组织;针对合金不同变形区域的特征和体系储存能分布不均匀的特点,分别引入反映不同变形区域的储存能分布的权重因子和变形区域的特征状态因子,构造多状态的非均匀自由能密度函数.在此基础上,应用相场动力学方程模拟了AZ31镁合金的静态再结晶过程的微结构演化,系统地分析了再结晶转变动力学曲线和Avrami曲线,以及储存能释放规律和再结晶晶粒尺度分布.模拟得到的动力学规律符合JMAK理论,所得的Avrami曲线可近似看成一条直线,对应于真应变ε=0.25,0.50,0.75和1.00,该直线的平均斜率分别为2.45,2.35,2.19和2.15.Avrami时间指数随变形量的增加而降低.变形程度大的合金,储存能释放的速度快,完成静态再结晶所需的时间短.基于本文提出的模型,结合相场方法计算模拟所得的结果与已有的理论结果和实验结果符合良好.
In order to obtain the deformed grain structure before static recrystallization, mesh distortion model and phase field model are combined to produce the initial grain structure before recrystallization of the deformed alloy. According to the characteristics of different deformed regions of the alloy and the uneven storage of energy in the system , The weight factor of storage energy distribution and the characteristic state factor of deformation zone are introduced respectively to construct the multi-state non-uniform free energy density function.On the basis of this, phase-field kinetic equation is used to simulate the growth of AZ31 magnesium The microstructure evolution of the alloy during the static recrystallization process was analyzed systematically, and the recrystallization kinetics curve and Avrami curve were analyzed systematically, and the release law of storage energy and the recrystallized grain size distribution were also analyzed. The kinetics of the simulation accorded with JMAK theory. The Avrami curve can be approximated as a straight line corresponding to true strains ε = 0.25, 0.50, 0.75 and 1.00, with an average slope of 2.45, 2.35, 2.19 and 2.15 respectively. Avrami time indices decrease with increasing deformation. A large degree of alloy, storage can release faster, the time required to complete the static recrystallization is short.Based on the model proposed in this paper, combined with the phase field The resulting simulation calculation results with existing theoretical and experimental results are in good agreement.