【摘要】 分别建立了喷雾冷却和平面凝固铸造的二维计算模型.根据对1070铝合金方锭末端冷却所测得的温度数据,反求出不同水压下冷却面表面温度与换热系数的变化规律,并将其作为边界条件导入平面凝固铸造的计算模型进行可靠性验证.结果表明:界面换热系数随冷却面温度的降低先升高后降低,在400K左右达到峰值.随着冷却水压的增加,换热系数的峰值和峰值对应的温度值也相应增大.铸造实验测温结果表明:所用平面凝固装置可实现凝固前沿宏观上呈平面上升,且凝固过程中铸锭各处冷却均匀;与数学模型计算结果吻合良好,说明该模型可用于平面凝固铸造工艺方案的研究.更多还原

【Abstract】 2 D mathematical models of spray cooling and planar solidification casting were established. Using the temperature data measuring from 1070 aluminum alloy ingot, the relationships between the cooling surface temperature and heat transfer coefficient( HTC) under different cooling water pressures was derived reversely,which was used to verify the model of planar solidification casting. The results showed that the HTC firstly increases and then decreases with the decrease of the cooling surface temperature,and reaches the peak at about 400 K. The HTC peak value and its corresponding temperature increase with the cooling water pressure. The casting experiment results showed that the solidification front is macroscopically planar and the cooling rate of the ingot is uniformly distributed during the solidification. The simulation results well agree with the experimental results,which prove the capability of the model of planar solidification casting.更多还原