A Comprehensive Review of MAX Phases: Pioneering Next-Generation Bond Coats for Thermal Barrier Coatings

Thermal barrier coatings (TBCs) are critical for protecting high-temperature components in gas turbines and aerospace engines from thermal and oxidative stresses. However, conventional bond coats face challenges like rapid oxidation, thermal expansion mismatches, and limited durability. MAX phases, layered ternary carbides, nitrides, or borides with the formula M_{n+۱}AX_n (M: early transition metal, A: groups ۱۳–۱۶ element, X: carbon, nitrogen, or boron), offer a promising alternative. These materials combine metallic properties (high electrical/thermal conductivity, ductility, machinability) with ceramic attributes (high melting points, oxidation resistance, stiffness), enabling superior performance in harsh environments. This comprehensive review synthesizes advancements in MAX phase bond coats for TBCs, focusing on compositions like Cr₂AlC, Ti₂AlC, V₂AlC, Mo₂AlC, and W₂AlC. Key deposition techniques, including spark plasma sintering (SPS), high-velocity atmospheric plasma spraying (HV-APS), physical vapor deposition (PVD), cold spraying, vacuum-arc deposition, and slurry coating, are evaluated. Multi-scale simulations optimize thermo-mechanical properties, while innovations in accident-tolerant fuel (ATF) claddings, self-healing mechanisms, and coatings for additively manufactured substrates are highlighted. Challenges such as porosity control, inter-diffusion, phase stability under prolonged oxidation, and interface engineering are addressed. MAX phase coatings exhibit enhanced oxidation resistance, sustained electrical conductivity, and mechanical integrity, positioning them as next-generation solutions for extreme environments. Future research should focus on scalable processing, alloyed compositions for long-term stability, and integration with advanced manufacturing to accelerate industrial adoption

کلیدواژه ها:

MAX Phases ، Thermal Barrier Coatings ، Bond Coats ، Additively Manufactured Substrates