变温热处理过程的相场模拟及其参数标定

Phase-field Modeling of Heat Treatment Process with Variable Temperature and Its Parameter Calibration

航空发动机双性能涡轮盘热处理工艺的研究,大多采用试验的方法建立涡轮盘合金的热处理工艺数据库,但试验法的研究周期长、成本高,提出一种可用于预测变温热处理过程中晶粒演化行为的相场模型。为了模拟不同热处理温度下高温合金的晶粒演化行为,对相场模型进行改进,在相场模型中引入Arrhenius关系,用于描述高温合金晶界运动与温度的量化关系。基于改进的相场模型和拟合的模型参数,计算分析热处理过程中晶粒尺寸的变化和形貌演化规律。结果表明:计算数据与试验数据吻合,晶粒的演化规律与理论分析和试验观察结果一致,证明了拟合的Arrhenius关系中的晶界迁移速率M适用于模拟相应温度下的热处理过程,同时,以上结果也验证了该模型改进方法的可行性及其拟合参数的准确性。

For the research of heat treatment technology of aero-engine turbine discs with dual-performance,the experimental methods are mostly used to establish the database of heat treatment technology of turbine disk alloys.However,the experimental methods have a long research period and high cost.A phase field model that can be used to predict the grain evolution during heat treatment process with variable temperature is proposed.To simulate the grain evolution of superalloy at different heat treatment temperatures,the phase field model is improved by introducing the Arrhenius relationship,which describes the quantitative relationship between the grain boundary movement and temperature.Based on the improved phase field model and fitted model parameters,the grain average size and morphology evolution of superalloy FGH96 during the longer heat treatment process are simulated,and the simulated results are compared with the experimental results.The results show that the calculated data coincide with the experiment data,the evolution law of grain is consistent with the experimental observation and theoretical analysis.These results prove that the grain boundary mobility M in the Arrhenius relationship is suitable for simulating the heat treatment process at the corresponding temperature.At the same time,the feasibility of the improved method and accuracy of the fitted parameters of the phase-field model are verified.