Effect of post-deposition heat treatment on electrodeposited NiCoCrAlY coatings. (1st February 2017)

• Record Type: Journal Article
• Authors: Zhang, L. Z.; Bates, B. L.; Zhang, Y.
• Is Part Of: Surface engineering. Volume 33:Number 2(2017)
• Page Start: 136
• Page End: 141
• Publication Date: 2017-02-01
• Subjects: MCrAlY -- Electrodeposition -- Composite -- Heat treatment -- Chromium evaporation; Surfaces (Technology) -- Periodicals; Coatings -- Periodicals; 620.4405
• DOI: 10.1080/02670844.2016.1198451
• Languages: English
• ISSNs: 0267-0844

Abstract

Abstract : An electrolytic process was utilised to fabricate NiCoCrAlY coatings, involving deposition of a composite coating consisting of the (Ni, Co) matrix and CrAlY particles, followed by a diffusion heat treatment to convert the composite coating to the desired NiCoCrAlY microstructure. This study focused on the effects of the post-deposition heat-treating conditions (temperature and atmosphere) on the final coating microstructure and composition. The (Ni, Co)–CrAlY composite coatings were heat-treated for 2 h at 1000, 1100 and 1200°C in vacuum and Ar, respectively. Phase constituents and concentrations of the major elements in the coating after heat treatment were examined. Vacuum heat treatment at temperatures ≥1100°C resulted in a significant decrease in Cr content at the coating surface due to Cr evaporation. Heat treatment at 1200°C also caused outward diffusion of Ti from the substrate alloy to the coating layer.