Vaporization and its associated surface defect formation have become one of the most important challenges in manufacturing single-crystal components. During the kinetic-influenced casting and solution heat treatment of Ni-base superalloys, elements undergo processes of vaporization and deposition causing unpredictable defects. To quantitatively examine the vaporization phenomenon, partial vapor pressures of Ni, Al and Cr in Ni-base alloys were measured in the γ phase over the temperature range of 1473 K to 1650 K using Knudsen effusion mass spectrometry. Experimental results showed that the partial pressure of Al is about two orders of magnitude lower than that of Ni and five times lower than that of Cr, revealing that the vaporization of Al is almost negligible compared with those of Ni and Cr at solution heat treatment temperatures. Variation of partial pressures during homogenization of the as-cast Ni-base alloys was measured in long-term isothermal experiments at 1573 K. It was found that Cr vapor pressure decreases by a factor of two in the first 20 hours whereas the Ni and Al remain nearly constant.

中文翻译：

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镍基合金中Ni，Al和Cr的汽化及其对单晶组件制造过程中表面缺陷形成的影响

汽化及其相关的表面缺陷形成已经成为制造单晶组件中最重要的挑战之一。在对镍基高温合金进行动力学影响的铸造和固溶热处理期间，元素会经历汽化和沉积过程，从而导致不可预测的缺陷。为了定量检查汽化现象，在γ中测量了镍基合金中Ni，Al和Cr的部分蒸气压。使用Knudsen渗流质谱法在1473 K至1650 K的温度范围内固定相。实验结果表明，Al的分压比Ni的分压低两个数量级，比Cr的分压低五倍，这表明在固溶热处理温度下，Al的汽化率几乎比Ni和Cr的气化微不足道。 。在1573 K的长期等温实验中测量了铸态Ni基合金均质化过程中的分压变化。发现Cr蒸气压在开始的20小时内降低了两倍，而Ni和Al保持几乎恒定。