【摘要】 利用高温度梯度定向凝固技术——液态金属冷却LMC(liquid metal cooling)技术制备了单晶铸件,采用ProCAST有限元模拟软件包计算了LMC定向凝固工艺下,不同抽拉速度单晶高温合金铸件定向凝固过程的温度场,预测了拉速对单晶生长缺陷的影响。结果表明,模拟结果与实验结果吻合良好,计算的温度曲线在1100℃以上与实测温度曲线相比误差小于5%;随着抽拉速度的增加,凝固界面下凹,曲率增加,铸件缘板处出现杂晶的倾向增大。更多还原

【Abstract】 Single crystal superalloy castings were prepared by high gradient liquid metal cooling(LMC)process.The temperature fields at various withdrawal rates during LMC process have been calculated with ProCAST software.The impact of the withdrawal rates on formation of stray grains was predicted.The results show that the discrepancy between the measured and the calculated temperature is lower than 5% above 1 100 ℃.The curvature of the solidification interface increased with increasing the withdrawal rates.Formation of spurious grains at platform of the single crystal castings was more sensitive at higher withdrawal rates.更多还原