2025/12/17 by Boakye, Dennis, Deng, Chuang
Engineering · #Additive Manufacturing Materials and Processes #FOS: Physical sciences #High Entropy Alloys Studies #High-Temperature Coating Behaviors #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2512.15517
openalex publication_date 2025/12/17 · openalex created_date 2025/12/19 · openalex updated_date 2026/07/28
The development of oxidation-resistant high-entropy alloy (HEA) bond coats is restricted by the limited understanding of how multi-principal element interactions govern scale formation across temperatures. This study uncovers new oxidation trends in NiCoCrAl HEAs using a data-driven analysis of high-fidelity experimental oxidation data. The results reveal a clear temperature-dependent transition between alumina- and chromia-dominated protection, identifying the compositional regimes where alloys rich in Al dominate at ≥1150 °C, mixed Al-Cr chemistries are optimal at intermediate temperatures, and, unexpectedly, Cr-rich low-Al alloys perform best at 850 °C-challenging the assumption that high Al is universally required. The effects of Hf and Y are shown to be strongly composition-dependent with Hf producing the largest global reduction in oxidation rate, while Y becomes effective primarily in NiCo-lean alloys. Y-Hf co-doping offers consistent improvement but exhibits site-saturation behavior. These insights identify new high-performing HEA bond-coat families, including \mathrmNi17Co23Cr30Al30 as a substitute for conventional mutlilayer thermal barrier coatings.