Small punch creep testing of thermally sprayed Stellite 6 coating: A comparative study of as-received vs post-heat treatment
Jackson, G.A.; Bai, M.; Pala, Z.; Hussain, T.; Sun, W.
TANVIR HUSSAIN Tanvir.Hussain@nottingham.ac.uk
Thermally sprayed Stellite 6 coatings offer high wear and corrosion-erosion resistance at high temperature but the creep behaviour of such coatings is not well understood. In this paper, the microstructure and creep behaviour of a HVOF Stellite 6 coating was investigated. The coating was tested in the as-sprayed condition and after an isothermal heat-treatment of 1 h at 1050 °C. The as-sprayed coating comprised FCC Co-Cr-W solid solution with 2–3 wt% HCP phase, whereas the heat-treated coating comprised FCC Co-Cr-W solid solution, 11 wt% M23C6 carbides and 7 wt% M7C3 carbides. Small punch creep tests were conducted at 700 °C on the as-sprayed and heat-treated coatings. The heat-treated coating exhibited minimum steady-state strain rates approximately 2 orders of magnitude lower than the as-sprayed coating when tested at similar loads, leading to times to failure approximately two orders of magnitude longer for the heat-treated coating within the selected load range. Fracture analysis showed cracking along powder particle boundaries was the main mode of cracking in the as-sprayed coating whereas for the heat-treated coating, fracture along the carbide / matrix interface was the main fracture mechanism.
|Journal Article Type||Article|
|Publication Date||Mar 11, 2019|
|Journal||Materials Science and Engineering: A|
|Peer Reviewed||Peer Reviewed|
|APA6 Citation||Jackson, G., Bai, M., Pala, Z., Hussain, T., & Sun, W. (2019). Small punch creep testing of thermally sprayed Stellite 6 coating: A comparative study of as-received vs post-heat treatment. Materials Science and Engineering: A, 749, 137-147. https://doi.org/10.1016/j.msea.2019.02.030|
|Keywords||Small punch creep; HVOF; Stellite 6; Creep; Fracture; Mechanical properties|
|Additional Information||This article is maintained by: Elsevier; Article Title: Small punch creep testing of thermally sprayed Stellite 6 coating: A comparative study of as-received vs post-heat treatment; Journal Title: Materials Science and Engineering: A; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.msea.2019.02.030; Content Type: article; Copyright: © 2019 The Author(s). Published by Elsevier B.V.|