Sliding wear investigation of suspension sprayed WC-Co nanocomposite coatings.

Ahmed, R.; Ali, O.; Faisal, N. H.; Al-Anazi, N.M.; Al-Mutairi, S.; Toma, F.-L.; Berger, L.-M.; Potthoff, A.; Goosen, M.F.A.

Abstract

Sliding wear evaluation of nanostructured coatings deposited by Suspension High Velocity Oxy-Fuel (S-HVOF) and conventional HVOF (Jet Kote (HVOF-JK) and JP5000 (HVOF-JP)) spraying were evaluated. S-HVOF coatings were nanostructured and deposited via an aqueous based suspension of the WC-Co powder, using modified HVOF (TopGun) spraying. Microstructural evaluations of these hardmetal coatings included X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray Spectroscopy (EDX). Sliding wear tests on coatings were conducted using a ball-on-flat test rig against steel, silicon nitride (Si3N4) ceramic and WC-6Co balls. Results indicated that nanosized particles inherited from the starting powder in S-HVOF spraying were retained in the resulting coatings. Significant changes in the chemical and phase composition were observed in the S-HVOF coatings. Despite decarburization, the hardness and sliding wear resistance of the S-HVOF coatings was comparable to the HVOF-JK and HVOF-JP coatings. The sliding wear performance was dependent on the ball-coating test couple. In general a higher ball wear rate was observed with lower coating wear rate. Comparison of the total (ball and coating) wear rate indicated that for steel and ceramic balls, HVOF-JP coatings performed the best followed by the S-HVOF and HVOF-JK coatings. For the WC-Co ball tests, average performance of S-HVOF was better than that of HVOF-JK and HVOF-JP coatings. Changes in sliding wear behavior were attributed to the support of metal matrix due to relatively higher tungsten content, and uniform distribution of nanoparticles in the S-HVOF coating microstructure. The presence of tribofilm was also observed for all test couples.

Citation

AHMED, R., ALI, O., FAISAL, N.H., AL-ANAZI, N.M., AL-MUTAIRI, S., TOMA, F.-L., BERGER, L.-M., POTTHOFF, A. and GOOSEN, M.F.A. 2015. Sliding wear investigation of suspension sprayed WC-Co nanocomposite coatings. Wear [online], 322-323, pages 133-150. Available from: https://doi.org/10.1016/j.wear.2014.10.021

• Journal Article Type: Article
• Acceptance Date: Oct 31, 2014
• Online Publication Date: Nov 13, 2014
• Publication Date: Jan 15, 2015
• Deposit Date: Nov 11, 2015
• Publicly Available Date: Nov 14, 2015
• Journal: Wear
• Print ISSN: 0043-1648
• Electronic ISSN: 1873-2577
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 322-323
• Pages: 133-150
• DOI: https://doi.org/10.1016/j.wear.2014.10.021
• Keywords: Nanostructured coating; Sliding wear; WC-Co coating; Suspenssion spraying; Tribology
• Public URL: http://hdl.handle.net/10059/1341
• Contract Date: Nov 11, 2015