Abstract
Magnesium-yttrium-rare earth element alloys such as WE43 are potential candidates for future bioabsorbable orthopedic implant materials due to their biocompatibility, mechanical properties similar to human bone, and the ability to completely degrade in vivo. Unfortunately, the high corrosion rate of WE43 Mg alloys in physiological environments and subsequent loss of structural integrity limit the wide applications of these materials. In this study, the effect of chemical heterogeneity and microstructure on the corrosion resistance of two alloys with different metallurgical states was investigated: Cast (as in traditional preparation) and as-deposited produced by magnetron sputtering. The corrosion behavior was studied by potentiodynamic polarization and electrochemical impedance spectroscopy tests in blood bank buffered saline solution. It was found that the as-deposited alloy showed more than one order of magnitude reduction in corrosion current density compared to the cast alloy, owing to the elimination of micro-galvanic coupling between the Mg matrix and the precipitates. The microstructure and formation mechanism of corrosion products formed on both alloys were discussed based on immersion tests and direct measurements of X-ray photoelectron spectrometry (XPS) and cross-sectional transmission electron microscopy (TEM) analysis.
| Original language | English |
|---|---|
| Pages (from-to) | 6399-6411 |
| Number of pages | 13 |
| Journal | Journal of Materials Chemistry B |
| Volume | 7 |
| Issue number | 41 |
| DOIs | |
| State | Published - 2019 |
| Externally published | Yes |
Funding
This research was financially supported by the National Science Foundation under Grant DMR-1856196. The authors thankfully acknowledge the discussion of results with Kimmo Lhteenkorva and Christopher Stahle from ConMed Corporation and Dr Alberto A. Sags from University of South Florida. H. M. acknowledges the assistance of Nicholas G. Rudawski from the University of Florida for XPS analysis. The sample preparation and most material characterization were performed at the Nano Research and Educational Center (NREC) at the University of South Florida. XPS analysis was performed at the University of Florida This research was financially supported by the National Science Foundation under Grant DMR-1856196. The authors thankfully acknowledge the discussion of results with Kimmo Lähteen-korva and Christopher Stahle from ConMed Corporation and Dr Alberto A. Sagüés from University of South Florida. H. M. acknowledges the assistance of Nicholas G. Rudawski from the University of Florida for XPS analysis. The sample preparation and most material characterization were performed at the Nano Research and Educational Center (NREC) at the University of South Florida. XPS analysis was performed at the University of Florida.
| Funders | Funder number |
|---|---|
| ConMed Corporation | |
| National Science Foundation | 1856196, DMR-1856196 |
| University of Florida | |
| University of South Florida |