Fabrication of thermal barrier coatings onto polyimide matrix composites via air plasma spray process

• Published in: Surface & coatings technology Vol. 207; pp. 421 - 429
• Main Authors: Huang, Wenzhi, Fan, Xizhi, Zhao, Yu, Zhou, Xin, Meng, Xiangsheng, Wang, Ying, Zou, Binglin, Cao, Xueqiang, Wang, Zhen
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 25.08.2012; Elsevier
• Subjects: Air plasma spray; Applied sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Failure; Materials science; Metals. Metallurgy; Nonmetallic coatings; Physics; Production techniques; Surface treatment; Surface treatments; Thermal ablation resistance; Thermal shock resistance; Thermal stress; Thermal stress; Thermal ablation resistance; Thermal shock resistance; Failure; Air plasma spray; Plasma; Hot spraying; Surface treatments; Air; Non metal coating; Ablation; Fabrication; Composite materials; Thermal shock; Polyimides; Thermal barriers; Plasma arc spraying; Thermal stresses
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2012.07.042

Thermal barrier coatings were fabricated on polyimide matrix composites via air plasma spray process. The phase structures and microstructural evolution of the coatings before and after testing were characterized by powder X-ray diffraction and scanning electron microscopy. During thermal shock test at 400°C, thermal shock lifetime of the coating systems increased with the decrease of thickness of Al layer as well as the increase in that of YSZ layer. The coating system consisted of 30μm Al bond layer and 130μm YSZ top layer exhibited the best thermal shock resistance. Meanwhile, owing to the protection of the coating system, the weight loss of the sample decreased from 7.05% to 1.90%, while the corresponding mass ablation rate reduced from 0.48mgs−1 to 0.21mgs−1. Failure mechanism of the coatings was mainly ascribable to the residual stress during deposition, oxidation of substrate and thermal stress induced by mismatch in thermal expansion. ► Thermal barrier coatings were fabricated on polyimide composites via air plasma spray process. ► TBC coating consisted of 30μm Al layer and 130μm YSZ layer exhibited best thermal shock resistance. ► TBC coating system provided good thermal ablation protection for the substrate. ► Failure mechanism was ascribable to residual stress, oxidation of substrate and thermal stress.