消失模铸造充型与凝固过程的计算机仿真

根据消失模铸造液态金属充型及液态金属—模样界面的推进机制,提出了充型过程界面推移位置的人工神经网络算法。根据计算得出的界面位置,用SOLA算法计算了充型过程中液态金属的流场,并耦合计算了充型过程中的温度场。根据计算得到的充型结束时铸件及铸型温度场,求解三维导热微分方程,计算了铸件凝固过程的温度场。结合消失模铸造型壁移动的规律,预测了球墨铸铁件消失模铸造的收缩缺陷。计算模拟结果与充型过程实际测试结果及铸件解剖结果一致。

COMPUTER SIMULATION ON MOLD FILLING AND SOLIDIFICATION PROCESS OF LOST FOAM CASTING

The artificial neural network technique is introduced to calculate the locations of metal-pattern interface according to the mechanism of the molten metal filling and metal front moving during the filling process of lost foam casting (LFC). Based on the calculated interface location,the fluid flow of the molten metal during mold filling process is calculated by use of SOLA method and the temperature distribution is coupled with. The temperature distribution during the solidification process is calculated by the numerical solution of the three-dimensional heat conduction partial differential equation according to the casting and mold temperature distribution at the moment of filling process ending.The shrinkage derect of duchtile iron lost foam casting is predicted according to the characteristics of mold wall movement in LFC. The results of simulation are consistent both with the results of mold filling test and with the results of casting intersecting.