Preparation of ZrO2-Al2O3 micro-laminated coatings on stainless steel and their high temperature oxidation resistance
(1. Beijing Key Laboratory for Corrosion, Erosion and Surface Technology,
University of Science and Technology Beijing, Beijing 100083, China;
2. School of Chemistry and Chemical Engineering, Ji’nan University,
Ji’nan 250022, China;
3. School of Engineering, The University of Auckland, Private Bag 92019,
Auckland, New Zealand)
University of Science and Technology Beijing, Beijing 100083, China;
2. School of Chemistry and Chemical Engineering, Ji’nan University,
Ji’nan 250022, China;
3. School of Engineering, The University of Auckland, Private Bag 92019,
Auckland, New Zealand)
Abstract: Micro-laminated ZrO2-Al2O3 coatings were prepared by electrochemical depositing ZrO2 film and Al2O3 film alternatively in ethanol solutions containing aluminum nitrate and zirconium nitrate, with small amounts of yttrium nitrate added respectively into both solutions. The micro-laminated ZrO2-Al2O3 coating is of nanostructure. FE-SEM analyses show that the cross section of the micro-laminated coatings has alternate six-layer films of ZrO2 and Al2O3, with the thickness of each layer in the range of nanometer or submicron. The surface of the micro-laminated coatings is composed of nano-particles. SEM, XRD and mass gain measurement were adopted to study the oxidation resistance of coatings on stainless steel. It has been found that all the coatings are effective in protecting the substrate from oxidation, and micro-laminated coatings exhibit more excellent protectiveness performance. Mechanisms accounting for such effects have been discussed.
Key words: ZrO2; Al2O3; micro-laminated coatings; electro-deposition; oxidation; stainless steel