Analysis of structure and microhardness of Al2O3-40 wt.% TiO2/NiCoCrAl gradient coating with in-situ needle-like phase reinforcement after high-temperature treatment. Issue 12 (15th August 2019)

• Record Type: Journal Article
• Authors: He, Xuan; Yuan, Xiaohu; Xu, Hao; Song, Peng; Yu, Xiao; Li, Chao; Huang, Taihong; Li, Qiaolei; Lü, Kaiyue; Feng, Jing; Lü, Jianguo; Lu, Jiansheng
• Is Part Of: Ceramics international. Volume 45:Issue 12(2019)
• Page Start: 14546
• Page End: 14554
• Publication Date: 2019-08-15
• Subjects: Gradient coating -- Al2O3 -- TiO2 -- NiCoCrAl -- Microhardness; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.04.171
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: This study investigated the structural evolution and microhardness of Al2 O3 –40 wt.% TiO2 /NiCoCrAl gradient coatings deposited by atmospheric plasma spraying (APS) after high-temperature treatment carried out at 800 °C in air for 600 h. The gradient region exhibited a different ceramic growth and oxidation behaviour at different zones. The nonhomogeneous needle-like γ-Al2 O3 phase was formed at the ceramic region, whereas the homogeneous needle-like NiAl2 O4 phase was formed at the NiCoCrAl oxidation region close to the ceramic coating. And the ingrowth Cr-rich phase existed inside the NiCoCrAl splats at the gradient region close to the bond coating. An obviously microhardness improvement of the coating can be measured by a Vickers microhardness tester. The formation of the needle-like phase has an effect on the reinforcement of coating.