Abstract This work explores the conditions for safe heat treatment of aluminum alloys containing lithium and magnesium in molten sodium nitrate (NaNO3) bath furnaces, and conditions where industrial accidents may occur. Using calorimetry coupled to classical thermodynamics, the strength of classical thermodynamics when analyzing thermal curves was demonstrated through a series of small-scale thermal analyses of various aluminum alloys in contact with sodium nitrate. This system was selected to illustrate reactions that may lead to severe and violent heat effect phenomena. Using idealized binary alloys, severe oxidation of magnesium- and lithium-rich aluminum alloy samples were shown to occur near 500 °C, a temperature range dangerously close to the operating temperature of solution heat treatment furnaces in manufacturing processes of heat treatable aluminum alloy sheets used in the aerospace industry. Commercial aluminum alloys AW257, 2198, 2024, and 1050 were also assessed with the same tools. The temperature that needed to be reached for these commercial aluminum alloys to react with molten sodium nitrate was significantly higher than the normal operating temperature of a conventional solution heat treatment furnace.

中文翻译：

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熔融硝酸盐与可热处理铝合金的化学反应性的量化

摘要 本文探讨了含锂镁铝合金在熔融硝酸钠(NaNO3)浴炉中安全热处理的条件，以及可能发生工业事故的条件。使用与经典热力学耦合的量热法，通过对与硝酸钠接触的各种铝合金进行一系列小规模热分析，证明了经典热力学在分析热曲线时的强度。选择该系统是为了说明可能导致严重和剧烈的热效应现象的反应。使用理想化的二元合金，富含镁和锂的铝合金样品在 500 °C 附近发生严重氧化，在航空航天工业中使用的可热处理铝合金板的制造过程中，温度范围非常接近固溶热处理炉的工作温度。商用铝合金 AW257、2198、2024 和 1050 也使用相同的工具进行了评估。这些商用铝合金与熔融硝酸钠反应所需达到的温度明显高于传统固溶热处理炉的正常工作温度。