Abstract Treatment of liquid aluminum alloys in low vacuum conditions is often applied for parts production in the automotive and aerospace industry because of its effectiveness in removing dissolved gases. Because of the low vapour pressure of aluminum, concentrations of the most unwanted elements can be significantly reduced at lower pressures. Presented work analyzing kinetics parameters for elemental evaporation from liquid Al7Si4Cu alloy. The pressure inside mullite refractory material was below 2.1 kPa for melt temperatures between 760 and 910 °C. The alloy’s chemical composition was characterized by the Inductively Coupled Plasma Mass Spectrometry method. Lead, Zinc, and Mercury were reduced at the highest rate while the lowest evaporation occurred for key alloying elements such as Silicon and Copper. Higher evaporation rates were achieved at higher temperatures. The evaporation ratios, volatility coefficients, reaction rate constants, mass transfer coefficients, and elemental evaporation susceptibility on temperature increase were deduced for 16 elements. The obtained results confirmed that keeping molten aluminum alloys in low vacuum conditions for one hour is an efficient method in removing unwanted elements with great potential for further improvement in industrial conditions.

中文翻译：

---

熔融Al7Si4Cu合金元素蒸发的热力学和动力学研究

摘要 在低真空条件下对液态铝合金进行处理，因其能有效去除溶解气体而常用于汽车和航空航天工业的零件生产。由于铝的蒸气压低，最不需要的元素的浓度可以在较低的压力下显着降低。介绍了分析液态 Al7Si4Cu 合金元素蒸发动力学参数的工作。对于 760 至 910 °C 的熔体温度，莫来石耐火材料内部的压力低于 2.1 kPa。合金的化学成分通过电感耦合等离子体质谱法表征。铅、锌和汞的减少率最高，而硅和铜等关键合金元素的蒸发率最低。在更高的温度下实现了更高的蒸发率。推导了16种元素的蒸发比、挥发系数、反应速率常数、传质系数和元素蒸发对温度升高的敏感性。获得的结果证实，将熔融铝合金在低真空条件下保持一小时是去除不需要的元素的有效方法，具有进一步改善工业条件的巨大潜力。