Skip to main content

Research Repository

Advanced Search

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


Omar Ali

Rehan Ahmed

Filofteia-Laura Toma

Lutz-Michael Berger

Björn Matthey

Khalid Ahmed


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.


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:

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
Keywords Alumina coating; Sliding wear; Structure-property relationships; Suspension; Thermal spray coatings; Wear mechanisms
Public URL


You might also like

Downloadable Citations