The influence of preparative parameters on the adhesion of alumina washcoats deposited on metallic supports

• Published in: Applied surface science 2007-09, Vol.253 (23), p.9099-9104
• Main Authors: Jia, Jingsheng, Zhou, Jin, Zhang, Jianguo, Yuan, Zhongshan, Wang, Shudong
• Format: Article
• Language: English
• Subjects: Adhesion; Alumina coating; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Mechanical and acoustical properties; adhesion; Metallic support; Physics; Solid surfaces and solid-solid interfaces; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2007.05.034

Well-adhered alumina washcoats on FeCrAl metallic supports were prepared using boehmite sols and alumina slurries. The microstructure and the surface performance of the washcoat/support were investigated by SEM, XRD, and ultrasonic vibration. The effects of the main preparative parameters on the coating adherence were studied. The optimal coating conditions are presented as follows: pre-oxidation of the metallic supports was performed at 900 °C for 10 h, the sol layer loadings were 2.0–6.6 wt.%, and the slurry layer loadings were less than 25.3 wt.%. The sol layer drying was performed at 30 °C for 1 h and that for the slurry layer the drying was performed at 120 °C for 2 h, and the coating calcining was performed at 900 °C for 2 h. The SEM photographs of coated samples show that alumina washcoats were well deposited on the metallic supports.