Tribological properties of HVOF-sprayed WC-Co coatings deposited from Ni-plated powders at elevated temperature
SCIE
SCOPUS
- Title
- Tribological properties of HVOF-sprayed WC-Co coatings deposited from Ni-plated powders at elevated temperature
- Authors
- Jafari, Majid; Han, Jong-Chan; Seol, Jae-Bok; Park, Chan-Gyung
- Date Issued
- 2017-10
- Publisher
- ELSEVIER SCIENCE SA
- Abstract
- WC-Co coatings with low degree of WC decomposition were deposited from electroless Ni-plated micro- and nano-structured feedstock powders using high velocity oxygen fuel (HVOF) spraying. Dry sliding friction and wear behavior of the resultant coatings, referred to as Ni/mc-WC and Ni/nc-WC, were investigated by using sintered alumina (Al(2)o(3)) as the mating material at 700 degrees C For the purpose of comparison, similar experiments were carried out on conventional micro- and nano-structured coatings, denoted as me-WC and nc-WC. The worn scars were examined by field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectroscopy (EDS). The wear resistance of Ni/mc-WC and Ni/nc-WC coatings at 700 degrees C was found to be 45% and 72% greater than that of me-WC and nc-WC coatings, respectively. Moreover, Ni/mc-WC and Ni/nc-WC coatings exhibited a significantly lower friction coefficient with negligible fluctuations as compared to me-WC and nc-WC. The microscopic analyses of me-WC and nc-WC worn surface revealed the presence of plastically deformed and discontinuous tribofilms, made up of a mixture of MWO4/WO3 (M = Co) and Al2O3, severe cracking and delamination especially at the interface of tribofilm and the underlying surface. In contrast, examination of Ni/mc-WC and Ni/nc-WC substantiated that a large area of the coatings surface is covered by a dense and adhered MWO4-type oxide layer (M = Co, Ni), which provides a more protection against wear at elevated temperature. (C) 2017 Elsevier B.V. All rights reserved.
- Keywords
- WEAR BEHAVIOR; OXIDATION BEHAVIOR
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/92001
- DOI
- 10.1016/j.surfcoat.2017.08.026
- ISSN
- 0257-8972
- Article Type
- Article
- Citation
- SURFACE & COATINGS TECHNOLOGY, vol. 327, page. 48 - 58, 2017-10
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