| Abstract: |
Alternative to Electrolytic Hard Chrome (EHC) method, which is still widely utilized in the printing, automotive and off-shore industries, has been widely developed the past decade by conventional HVOF processes and more recently HVAF systems, which are processing at higher kinetic energy and more particularly at lower temperature, significantly increasing wear and corrosion resistance properties. A dedicated Internal Diameter HVAF system is here presented, and coatings characteristics are compared to the one obtained by standard HVAF coatings. Specially R&D designed fixtures with inside bore of 200 mm have been manufactured for this purpose, with possibility to spray samples at increasing depth up to 400 mm while simulating closed bottom bore spraying. WC-based, Cr3C2-based, Triballoy and Stainless Steel powder feedstock materials have been deposited onto high-strength steel substrates. Respective coating microstructures, adhesion strength, wear and corrosion resistance are presented and discussed for further optimization of coating performances.
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