Mechanical, structural and dissolution properties of heat treated thin-film phosphate based glasses

Stuart, Bryan W.; Gimeno-Fabra, Miquel; Segal, Joel; Ahmed, Ifty; Grant, David M.

Abstract

Here we show the deposition of 2.7 μm thick phosphate based glass films produced by magnetron sputtering, followed by post heat treatments at 500 °C. Variations in degradation properties pre and post heat treatment were attributed to the formation of Hematite crystals within a glass matrix, iron oxidation and the depletion of hydrophilic P-O-P bonds within the surface layer. As deposited and heat treated coatings showed interfacial tensile adhesion in excess of 73.6 MPa; which surpassed ISO and FDA requirements for HA coatings. Scratch testing of coatings on polished substrates revealed brittle failure mechanisms, amplified due to heat treatment and interfacial failure occurring from 2.3 to 5.0 N. Coatings that were deposited onto sandblasted substrates to mimic commercial implant surfaces, did not suffer from tensile cracking or trackside delamination showing substantial interfacial improvements to between 8.6 and 11.3 N. An exponential dissolution rate was observed from 0 to 2 h for as deposited coatings, which was eliminated via heat treatment. From 2 to 24 h ion release rates ordered P > Na > Mg > Ca > Fe whilst all coatings exhibited linear degradation rates, which reduced by factors of 2.4–3.0 following heat treatments.

Citation

Stuart, B. W., Gimeno-Fabra, M., Segal, J., Ahmed, I., & Grant, D. M. (2017). Mechanical, structural and dissolution properties of heat treated thin-film phosphate based glasses. Applied Surface Science, 416, 605-617. https://doi.org/10.1016/j.apsusc.2017.04.110

• Journal Article Type: Article
• Acceptance Date: Apr 15, 2017
• Online Publication Date: Apr 18, 2017
• Publication Date: Sep 15, 2017
• Deposit Date: Jun 2, 2017
• Publicly Available Date: Jun 2, 2017
• Journal: Applied Surface Science
• Print ISSN: 0169-4332
• Electronic ISSN: 1873-5584
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 416
• Pages: 605-617
• DOI: https://doi.org/10.1016/j.apsusc.2017.04.110
• Keywords: Heat treatment; Phosphate glass; Mechanical properties; Ion leaching; Osseointegration; Thin films
• Public URL: https://nottingham-repository.worktribe.com/output/882811
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0169433217311273
• Additional Information: This article is maintained by: Elsevier; Article Title: Mechanical, structural and dissolution properties of heat treated thin-film phosphate based glasses; Journal Title: Applied Surface Science; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.apsusc.2017.04.110; Content Type: article; Copyright: © 2017 The Author(s). Published by Elsevier B.V.
• Contract Date: Jun 2, 2017