High-Throughput Nanomechanical Screening of Phase-Specific and Temperature-Dependent Hardness in AlxFeCrNiMn High-Entropy Alloys

Development of structural materials for service under extreme conditions is slowed by the lack of high-throughput test protocols. Here, a method that integrates high-throughput nanoindentation mapping with precise temperature control under a vacuum atmosphere is demonstrated. High-entropy alloys (HEAs) may possess the strength and stability required of high-temperature structural materials in next-generation nuclear applications. These alloys, including the compositional variation Al x FeCrNiMn ( x = 0, 0.3, 1) presented in this work, have distinct microstructural morphologies, and nanoindentation mapping reveals the mechanical behavior of the distinct phases as a function of temperature up to 400°C. FeCrNiMn (Al = 0) consists of a face-centered cubic (FCC) matrix with body-centered cubic (BCC) precipitates and exhibits significant softening in both phases at elevated temperature. In contrast, both the FCC phase and FCC–BCC phases present in Al 0.3 FeCrNiMn show approximately 90% retention of the room temperature hardness at 400°C, and AlFeCrNiMn with BCC and B2 structures shows a similar 85% retention of hardness.