Mechanical and Corrosion Testing of Magnesium WE43 Specimens for Pitting Corrosion Model Calibration

Abstract

Computational modeling can play an important role in the analysis, design, and development of complex medical devices such as biodegradable coronary stents. In this study, experimental mechanical and corrosion testing is conducted to characterize the mechanical and corrosion behavior of magnesium WE43 alloy, a candidate base material for biodegradable magnesium alloy stents. Previously developed uniform and pitting corrosion models are calibrated based on in vitro mechanical and corrosion testing of magnesium WE43 alloy specimens. The calibrated pitting corrosion model can capture the mechanical and corrosion behavior of magnesium WE43, including the experimentally observed non‐linear reduction in failure strength with mass loss, whereas the uniform corrosion model is incapable of capturing this trend. The calibrated corrosion models will be used in future research on magnesium alloy stents.

Computational modelling of magnesium stent mechanical performance in a remodelling artery: Effects of multiple remodelling stimuli

“…The stent is modelled using the mechanical properties of magnesium WE43 alloy where elasticity is considered linear and isotropic and described through Young's modulus and Poisson's ratio, and plasticity is described using J 2 flow theory and isotropic hardening.…”

“…Grogan and co‐workers originally developed phenomenological uniform and PC models and calibrated them based on experimental mechanical and corrosion testing of Mg AZ31 films. The corrosion parameters have been recalibrated (as described by Boland et al) for Mg WE43 alloy, and these are the corrosion parameters used in the present study. A detailed description of the PC model is provided in Appendix C.…”

“…For the PC model, three parameters (material corrosion rate, k U , Weibull function parameter, γ , and growth rate parameter, β ) must be determined. As described in Boland et al, these parameters are calibrated, and model performance validated against data generated in independent corrosion and corrosion followed by tensile loading experiments performed on unground electrical discharge machining (EDM) Mg WE43 samples. For all PC simulations, the calibrated corrosion parameters ( β = 0.8, γ = 0.2) are used.…”

A crystal plasticity based investigation of fretting fatigue in bioresorbable magnesium elastic stable intramedullary nails (ESINs)

“…(Grogan et al, 2011) developed a phenomenological pitting corrosion model for biodegradable magnesium alloys implemented for use in computational finite element software, such as Abaqus. Detailed descriptions of the pitting corrosion model can be found in Grogan et al (Grogan et al, 2011) and Boland et al (Boland et al, 2018.…”

“…Therefore, random orientations are assigned to different grains in the polycrystalline material. The pitting corrosion model has been calibrated using in-vitro corrosion experiments of Mg WE43 alloy (Boland et al, 2018). It should be noted that the Mg-RE (73-2) alloy which is used for simulations in this paper contains rare earth alloying elements, similar to the Mg WE43 alloys.…”