Refractory multicomponent boron-carbide high entropy oxidation-protective coating for carbon-carbon composites

• Published in: Surface & coatings technology Vol. 425; p. 127697
• Main Authors: Zhang, Hanzhu, Akhtar, Farid
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.11.2021; Elsevier BV
• Subjects: Boron; Carbides; Carbon; Carbon-carbon composite; Carbon-carbon composites; Ceramic coatings; Crystallites; Engineering Materials; Face centered cubic lattice; High-entropy ceramic; Liquefied petroleum gas; Magnetron sputtering; Materialteknik; Oxidation; Oxidation resistance; Protective coatings; Solid solutions; Stability tests; Thermal stability; High-entropy ceramic; Oxidation; Magnetron sputtering; Carbon‑carbon composite
• ISSN: 0257-8972; 1879-3347; 1879-3347
• DOI: 10.1016/j.surfcoat.2021.127697

A novel refractory multicomponent boron-carbide coating of 300 nm thickness, HfMoTaTi-BC, was deposited on carbon‑carbon composites (CCC). The coating showed a face-centred cubic (FCC) structure of lattice parameter of 0.4429 nm with an average crystallite size of 5 nm. The FCC coating transformed from single-phase solid solution into multiple ceramic carbides and boride phases at 900 °C during long-term thermal stability test. The exposure of HEC coated CCC to the flame (2000 °C) of liquefied petroleum gas (LPG) torch for 5 min revealed that the film had excellent resistance to oxidation and protected the CCC material under extreme aerothermal heating. •A novel boron-carbide high-entropy coating, HfMoTaTi-BC, was deposited on carbon-carbon composites for oxidation protection.•The HfMoTaTi-BC film of 300 nm thickness showed face-centred cubic (FCC) structure and hardness of 10.6 GPa.•The HfMoTaTi-BC film was transformed from single-phase solid solution into multiple ceramic carbide and boride phases at 900 °C in vacuum.•The exposure of HEC coated CCC to the flame (2000 °C) for 5 min revealed its excellent resistance to oxidation.