Microstructural evaluation of suspension thermally sprayed WC-Co nanocomposite coatings.

Ahmed, R.; Faisal, N.H.; Ali, O.; Al-Anazi, Nayef M.; Al-Mutairi, S.; Mamour, S.; Polychroniadis, E.K.; Goosen, M.F.A.

Abstract

Microstructural and sliding wear evaluations of nanostructured coatings deposited by Suspension High Velocity Oxy-Fuel (S-HVOF) spraying were conducted in as-sprayed and HIPed (Hot Isostatically Pressed) conditions. S-HVOF coatings were nanostructured via ball milling of the WC-12Co start powder, and deposited via an aqueous based suspension using modified HVOF (TopGun) spraying. Microstructural evaluations of these hardmetal coatings included TEM (Transmission Electron Microscopy), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Sliding wear tests were conducted using a ball-on-flat test rig. Results indicated that nanostructured features inherited from the start powder in S-HVOF spraying were retained in the resulting coatings. The decarburisation of WC due to a higher surface area to volume ratio was also observed in the S-HVOF coatings. Nanostructured and amorphous phases caused by the high cooling rates during thermal spraying crystallized into complex eta-phases after the HIPing treatment. Sliding wear performance indicated that the coating wear was lower for the HIPed coatings.

Citation

AHMED, R., FAISAL, N.H., ALI, O., AL-ANAZI, N.M., AL-MUTAIRI, S., MAMOUR, S., POLYCHRONIADIS, E.K. and GOOSEN, M.F.A. 2015. Microstructural evaluation of suspension thermally sprayed WC-Co nanocomposite coatings. In Polychroniadis, E.K., Oral, A.Y. and Ozer, M. (eds.) Proceedings of the 2nd International multidisciplinary microscopy and microanalysis congress 2014 (InterM), 16-19 October 2014, Oludeniz, Turkey. Springer proceedings in physics, 164. Cham: Springer [online], pages 31-38. Available from: https://doi.org/10.1007/978-3-319-16919-4_5

• Conference Name: 2nd International multidisciplinary microscopy and microanalysis congress 2014 (InterM)
• Conference Location: Oludeniz, Turkey
• Start Date: Oct 16, 2014
• End Date: Oct 19, 2014
• Acceptance Date: Oct 16, 2014
• Online Publication Date: May 5, 2015
• Publication Date: Dec 31, 2015
• Deposit Date: Sep 19, 2016
• Publicly Available Date: Sep 19, 2016
• Print ISSN: 0930-8989
• Publisher: Springer
• Pages: 31-38
• Series Title: Springer proceedings in physics
• Series Number: 164
• Series ISSN: 0930-8989
• ISBN: 9783319169187
• DOI: https://doi.org/10.1007/978-3-319-16919-4_5
• Keywords: Nanostructured coating; WCCo coating; Suspension spraying; Wear; Tribology
• Public URL: http://hdl.handle.net/10059/1751