A new MAX phases-based electroconductive coating for high-temperature oxidizing environment
T. A. Prikhna, О. P. Ostash, А.С. Куприн, Viktoriya Podhurska, Т. B. Serbenyuk, É. S. Gevorkyan, Mirosław Rucki, W. Żurowski, Wojciech Kucharczyk, V. B. Sverdun, M. V. Karpets, Semyon Ponomaryov, B. D. Vasyliv, Viktor Moshchil, М.A. Bortnitskaya
Abstract
In the paper, results of variations of structure, oxidation resistance, and electrical conductivity of novel MAX-phase composite coating are presented. The characteristics of highly dense Ti-Al-C composite bulks and vacuum-arc deposited 6 μm thick coatings before and after heating at 600 °C in air for 1000 h were compared. High electrical conductivity (σ = 1.3·106 S/m) of the highly resistant toward oxidation (Δm/S = 0.07 mg/cm2) Ti-Al-C coating was preserved after long-term heating in air. It was found that the specimen surface layers of MAX-phases Ti3AlC2 and Ti2AlC based bulks and chromium-containing Crofer 22APU steel became semiconductors because of high-temperature long-term oxidation (at 600 °C). The vacuum-arc deposited Ti-Al-C composite coating revealed high oxidation resistance and electrical conductivity along with good mechanical characteristics, namely nanohardness H (10 mN) = 9.5 ± 1.5 GPa, and Young’s modulus E = 190 ± 10 GPa, which make it very promising for interconnects of solid oxide fuel cells (SOFCs).