A comprehensive review of alloying effects in nickel-based single-crystal superalloys for turbine blades and vanes operating in a very aggressive environment of stress, oxidation and corrosion is presented. Exceptionally strong single-crystal superalloys have been developed containing increasing amounts of rhenium and decreasing amounts of chromium resulting in reduced environmental resistance. Interactions in a superalloy containing up to 15 alloying elements are complex and poorly understood. The superalloys can form brittle topologically closed-packed (TCP) phases unless the alloying additions are carefully selected. Development of superalloys with a required balance of strength and environmental resistance has been very challenging. Aluminium, chromium and tantalum are essential alloying elements for strength and environmental protection. Aluminium beyond an upper limit can lead to incipient melting during heat treatment necessary for achieving an optimum size and distribution of the γ′ phase. Rhenium and ruthenium additions contribute significantly to strength, while considerably degrading environmental resistance. Hafnium and yttrium singularly or in combinations improve oxidation and corrosion resistance. Progress in modelling based on thermodynamics, kinetics and regression analysis of prior data to simultaneously predict strength and environmental resistance has been limited since the strengthening and environmental degradation are distinctly separate mechanisms. The paper presents a critical review of alloying studies and provides an insight into future developments.

中文翻译：

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坚固，抗氧化和抗腐蚀的镍基高温合金的开发：对挑战，进展和前景的严格审查

介绍了在应力，氧化和腐蚀非常恶劣的环境中运行的涡轮叶片的镍基单晶高温合金中合金作用的全面综述。已经开发出了异常坚固的单晶高温合金，其中含有增加的amounts含量和减少的铬含量，导致降低的耐环境性。包含多达15种合金元素的高温合金中的相互作用是复杂的，并且了解甚少。除非仔细选择合金添加物，否则高温合金会形成脆性的拓扑密堆积（TCP）相。在强度和耐环境性之间取得平衡的超合金的开发一直是非常具有挑战性的。铝，铬和钽是强度和环境保护必不可少的合金元素。γ ′相。hen和钌的添加显着提高了强度，同时大大降低了对环境的耐受性。and和钇单独或组合可提高抗氧化性和抗腐蚀性。由于强化和环境降解是截然不同的机制，因此基于热力学，动力学和先前数据的回归分析同时预测强度和耐环境性的建模进展有限。本文对合金化研究进行了批判性综述，并对未来的发展提供了见识。