S. Kaabi Falahieh Asl, S. Nemeth, and M. J. Tan, "Mechanical Properties and Deposition Mechanism of Hydrothermally Deposited Calcium Phosphate Coating", 8th International Conference on Materials for Advanced Technologies (ICMAT 2015), 28-Jun-2015 to 03-Jul-2015, Singapore
Abstract:
Biocompatible and bioresorbable magnesium and its alloys could be ideal alternatives for currently used implants (Ti, Co-Cr alloys) to avoid or minimise stress shielding effect which is the main drawback of currently used implants. However, the high corrosion rate of magnesium and its alloys limit their practical application. Thus, in this study, a hydrothermal coating process was developed to provide protective biocompatible and bioresorbable coatings. X-ray diffraction patterns indicated sharp and well-defined peaks corresponding to monetite at low deposition temperature and a mixture of monetite and tricalcium phosphate at higher deposition temperature. Scanning electron microscopy study of the morphology showed increasingly denser coating with higher deposition temperature. Coating adhesion properties were evaluated by pull-out test indicating cohesive failure at 5.2 to 5.8 MPa stress. The current coatings showed high hardness which decreased by increasing the deposition temperature. Raman spectroscopy studies showed that the coatings consisted of two distinct layers: tricalcium phosphate and monetite. Electrochemical impedance spectroscopy confirmed that the coatings provided varying levels of corrosion protection. The corrosion results showed that the size of capacitance loops and the absolute impedance value (|Z|) increased by increasing the deposition temperature and corresponding growth in coating thickness. It was found that coating was partially converted to hydroxyapatite after 28 days immersion in simulated body fluid, confirming the bioactivity of the coatings. The results confirmed that the obtained coatings could be a promising candidate for surface modification of Mg for implant application.
License type:
PublisherCopyrights
Funding Info:
This research was supported by A*STAR, under its Singapore International Graduate Award (SINGA) scheme; by Singapore Institute of Manufacturing Technology, A*STAR; and Nanyang Technological University. Grant number is not applicable.
Description:
The provided article is a description of the research presented at the conference.