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Journal of Nanomaterials
Volume 2016, Article ID 7124218, 8 pages
http://dx.doi.org/10.1155/2016/7124218
Research Article

Surface Microstructure of Nanoaluminized CoCrAlY Coating Irradiated by HCPEB

Tianjin Key Laboratory for Civil Aircraft Airworthiness and Maintenance, Civil Aviation University of China, Tianjin 300300, China

Received 6 January 2016; Revised 16 March 2016; Accepted 12 April 2016

Academic Editor: Albano Cavaleiro

Copyright © 2016 Zhiyong Han et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A thermal sprayed CoCrAlY coating was prepared by air plasma spray on the surface of Ni-based superalloy GH4169; then, a nanoscale aluminum film was deposited with electron beam vacuum deposition on it. The coatings irradiated by high-current pulsed electron beam were investigated. After HCPEB treatment, the Al film was remelted into the bond coat. XRD result shows that Al and Al2O3 phase were recorded in the irradiated and aluminized coatings, while Co-based oxides which originally existed in the initial samples disappeared. Microstructure observations reveal that the original coating with porosity, cavities, and inclusions was significantly changed after HCPEB treatment as compact appearance of interconnected bulged nodules. Moreover, the grains on the irradiated coating were very refined and homogeneously dispersed on the surface, which could effectively inhibit the corrosive gases and improve the coating oxidation resistance.