Performance characterization of metallic substrates coated by HVOF WC-Co

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Date
2013-12-31
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Integral to the performance of high-velocity oxygen-fuel (HVOF) coatings is the thermo-mechanical interaction associated with the thermal misfit, or differences in thermal expansion coefficients (CTEs), between coating and substrate. This investigation reports results on the microstructures, chemical phase content, coating–substrate misfit residual stress, and wear resistance. For this purpose a systematic characterization of WC–Co sprayed coatings on a number of substrates covering a range of CTE values were pursued for both the as-coated and heat-treated conditions. The neutron diffraction technique in conjunction with sub-millimeter sized gauge volumes enabled depth-resolved studies of the stress in the coatings and substrates by paying special attention to the determination of the stress contribution attributed by the final spray process. In the as-coated condition the stress values in the coatings were compressive for CTEs larger than that of WC–Co and tensile for CTE lower than WC–Co. Wear resistance increased for increased compressive stress and macrohardness. In the heat-treated condition, this trend became enhanced due to increased compressive stress in the coatings. © 2013, Elsevier B.V.
Description
Keywords
Residual stresses, Microstructure, Spray coating, Wear resistance, Surface coating, Thermal expansion, Neutron diffraction
Citation
Venter, A. M., Oladijo, O. P., Luzin, V., Cornish, L. A., & Sacks, N. (2013). Performance characterization of metallic substrates coated by HVOF WC-Co. Thin Solid Films, 549, 330-339. doi:10.1016/j.tsf.2013.08.075
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