Influence of feedstock and thermal spray process on the phase composition of alumina coatings and their sliding wear.

Ali, Omar; Ahmed, Rehan; Toma, Filofteia-Laura; Berger, Lutz-Michael; Matthey, Björn; Faisal, Nadimul; Ahmed, Khalid

Abstract

Suspension thermal spraying is an emerging coating technology that enables the deposition of dense-structured ceramic coatings. As wear resistance is a main application field of alumina (Al2O3) coatings, this study aimed to evaluate the dry reciprocating sliding wear resistance of suspension sprayed high velocity oxy-fuel (S-HVOF) alumina coatings and to compare it with atmospheric plasma sprayed (APS) and HVOF coatings. Coatings were analyzed in the as-sprayed state and post-treated at 910 °C (hot isostatically pressed, HIPed) conditions. Wear tests were conducted using a tribometer, following the ASTM G133-02 standard and a sintered WC-6 wt.% Co ball as the counterbody. Coating characterization was done using scanning electron microscopy, X-ray diffraction and nanoindentation technique. Results indicate that the HVOF, HVOF-HIP and S-HVOF coatings had a high α-Al2O3 content, whereas the APS and APS-HIP coatings had a high γ-phase content together with high porosity. Sliding wear resistance was an order of magnitude higher for the S-HVOF and HVOF coatings than the APS and APS-HIPed coatings. This difference in wear performance was attributed to the high nanohardness, elastic modulus, dense microstructure and relatively high α-Al2O3 content in the HVOF, S-HVOF and HVOF-HIP coatings. Results are discussed in terms of the wear mechanism and structure-property relationship.

Citation

ALI, O., AHMED, R., TOMA, F.-L., BERGER, L.-M., MATTHEY, B., FAISAL, N. and AHMED, K. 2023. Influence of feedstock and thermal spray process on the phase composition of alumina coatings and their sliding wear. Journal of thermal spray technology [online], 32(7), pages 2028-2053. Available from: https://doi.org/10.1007/s11666-023-01597-z

• Journal Article Type: Article
• Acceptance Date: Apr 7, 2023
• Online Publication Date: Jun 19, 2023
• Publication Date: Oct 31, 2023
• Deposit Date: Jun 20, 2023
• Publicly Available Date: Jun 20, 2023
• Journal: Journal of thermal spray technology
• Print ISSN: 1059-9630
• Electronic ISSN: 1544-1016
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 32
• Issue: 7
• Pages: 2028-2053
• DOI: https://doi.org/10.1007/s11666-023-01597-z
• Keywords: Alumina coating; Sliding wear; Structure-property relationships; Suspension; Thermal spray coatings; Wear mechanisms
• Public URL: https://rgu-repository.worktribe.com/output/1992957