雾化喷射沉积成型凝固过程模拟Ⅱ.Al-Cu合金的计算结果

SIMULATION OF SOLIDIFICAFION BEHAVIOR IN SPRAY DEPOSITED PREFORM Ⅱ.Calculation Results For Al-Cu Alloy

根据本文作者提出的喷射沉积成型沉积体内的凝固模型，对典型的Al-Cu合金进行了计算分析结果表明，工艺参数（如沉积速率和沉积时雾化锥的温度）和材料的热物性（如界面换热系数）对沉积体内的凝固过程有明显影响在沉积热力学条件（沉积前雾化锥的热力学状态）相同的情况下，沉积表面的温度随工艺参数和材料热物性发生显著变化所以，必须以沉积表面温度的变化作为工艺控制的参考。

According to the solidification model in the spray formed preform proposed in the first part of this study, the solidification behavior of typical Al-Cu alloy is calculated and discussed.The result shows that processing parameters such as deposition rate and spray temperature at deposition, and material thermal physical properties such as surface heat transfer coefficient have apparent effects on solidification process in preform. Under the same deposition thermodynamic conditions such as the thermodynamic state of the sprat cone just before depositing on the surface of the preform, temperature of deposition surface will vary significantly as the processing parameters and material thermal physical properties change. Therefore the temperature of deposition surface should be taken as the major factor for spray processing control, and the formerly proposed principle for spray forming processing control should be reconsidered.