In-situ SEM observations of ultrasonic cavitation erosion behavior of HVOF-sprayed coatings

Haijun Zhang; Xiuyong Chen; Yongfeng Gong; Ye Tian; André McDonald; Hua Li

doi:10.1016/j.ultsonch.2019.104760

In-situ SEM observations of ultrasonic cavitation erosion behavior of HVOF-sprayed coatings

Ultrason Sonochem. 2020 Jan:60:104760. doi: 10.1016/j.ultsonch.2019.104760. Epub 2019 Aug 29.

Authors

Haijun Zhang¹, Xiuyong Chen², Yongfeng Gong¹, Ye Tian¹, André McDonald³, Hua Li⁴

Affiliations

¹ Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
² Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China; Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China; Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada. Electronic address: chenxiuyong@nimte.ac.cn.
³ Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
⁴ Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China; Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China. Electronic address: lihua@nimte.ac.cn.

PMID: 31493716
DOI: 10.1016/j.ultsonch.2019.104760

Abstract

Several typical high-velocity oxy-fuel (HVOF)-sprayed coatings, including WC-10Co4Cr coatings, Co-based coatings, WC-10Co4Cr/Co-based composite coatings, and Fe-based amorphous/nanocrystalline coatings were fabricated, and their cavitation behavior was evaluated in deionized water. Further, in-situ SEM surface observations were used to understand the microstructure of tested coatings. The results show that cavitation erosion initially occurred at pre-existing defects in the coatings. Meanwhile, it was found that cavitation erosion damage of the WC-10Co4Cr/Co-based composite coating, which contained a hard reinforcing phase (WC-10Co4Cr phase) and a soft matrix phase (Co-based phase), preferentially occurred at or around pores and microcracks in the reinforcement, rather than in the defect free matrix. This suggested that defects were a critical contributing factor to cavitation damage of the composite coatings. Furthermore, a mechanism was suggested to explicate the cavitation behavior of composite coatings. The approach of using in-situ SEM surface observations proved to be useful for the analysis of the cavitation mechanism of engineering materials and protective coatings.

Keywords: Cavitation erosion; Coatings; Failure mechanism; HVOF; In-situ SEM observation.