Computational Design and Experimental Characterization of a Novel Third-Generation Single Crystal Superalloy with Balanced High-Temperature Creep Strength and Oxidation Resistance

This paper presents the development of AMS20, a novel third-generation single crystal superalloySingle crystal superalloy designed for the next generation of aeroengines. The alloy designAlloy design utilizes a computational approach that combines empirical models and CALPHADCALculation of PHAse Diagrams (CALPHAD) calculations to identify compositions meeting targeted specifications. This methodology facilitates the selection of the final AMS20 alloy composition, aiming to optimize high-temperatureHigh-temperature oxidation creep propertiesCreep properties while preserving excellent high-temperature oxidationHigh-temperature oxidation resistance. The alloy was cast and single crystalSingle crystal bars were grown using the conventional Bridgman method. Subsequently, appropriate solution and aging treatments were developed, and the tensile and creep propertiesCreep properties of AMS20 were evaluated. A comparative analysis was performed against reference second- and third-generation single crystal superalloysSingle crystal superalloys, namely, CMSX-4CMSX-4, CMSX-10K, CMSX-4 PlusCMSX-4 Plus, and AGAT. Results indicate that AMS20 exhibits a remarkable combination of high-temperatureHigh-temperature oxidation creepCreep and oxidationOxidation resistance. Specifically, AMS20 demonstrates a creepCreep life at 1200 °C comparable to CMSX-10K alloy, while its cyclic oxidationCyclic oxidation performance at 1150 °C is akin to second-generation CMSX-4CMSX-4 alloy and notably superior to third-generation reference alloys. However, it is important to note that initial aging results highlight the sensitivity of AMS20 alloy to TCP phasesTCP phases at 1050 °C and its relatively narrow high-temperatureHigh temperature processingProcessing window. Yet AMS20 remains a promising single crystal superalloySingle crystal superalloy for the future generation of aircraft engines.