Diametral compression test method to analyse relative surface stresses in thermally sprayed coated and uncoated circular disc specimens.

Faisal, N. H.; Mann, L.; Duncan, C.; Dunbar, E.; Clayton, M.; Frost, M.; McConnachie, J.; Fardan, A.; Ahmed, R.

Abstract

In firsts of its investigation, a diametral compression destructive testing method (also known as Brazilian test) was performed on thermally sprayed coated and uncoated circular disc specimens to compare relative surface stresses. The coating investigated had about 250 μm thickness deposited on 4.76 mm thick Hastelloy®X substrate discs of 20 mm diameter. In the instrumented experiment (diametral compression test) strain gauge rosettes were used to measure strains on two circular surfaces of disc specimen (coated and uncoated sides) and converted to stress values for analysis. Where comparisons were made, the experimental and finite element simulation results were in some agreement with overall understanding of the diametral compression testing behaviour. For coated specimen, test results convey that higher stresses exist within the uncoated side of the specimen rather than the coated side. Although the methods proposed would be deemed most comparable to real life scenarios (e.g. to quantify coating delamination strength and failure mechanics), this type of experimental investigation has certain advantages and limitations.

Citation

FAISAL, N.H., MANN, L., DUNCAN, C., DUNBAR, E., CLAYTON, M., FROST, M., MCCONNACHIE, J., FARDAN, A. and AHMED, R. 2019. Diametral compression test method to analyse relative surface stresses in thermally sprayed coated and uncoated circular disc specimens. Surface and coatings technology [online], 357, pages 497-514. Available from: https://doi.org/10.1016/j.surfcoat.2018.10.053

• Journal Article Type: Article
• Acceptance Date: Oct 18, 2018
• Online Publication Date: Oct 22, 2018
• Publication Date: Jan 15, 2019
• Deposit Date: Oct 23, 2018
• Publicly Available Date: Oct 23, 2019
• Journal: Surface and coatings technology
• Print ISSN: 0257-8972
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 357
• Pages: 497-514
• DOI: https://doi.org/10.1016/j.surfcoat.2018.10.053
• Keywords: Diametral compression test; Brazilian test; Thermal spray coatings; Strain gauge; residual stress; Analytical method; Finite element
• Public URL: http://hdl.handle.net/10059/3190