Abstract
This paper presents a framework of experimental testing and crystal plasticity micromechanics for high cycle fatigue (HCF) of micro-scale L605 CoCr stent material. Micro-scale specimens, representative of stent struts, are manufactured via laser micro-machining and electro-polishing from biomedical grade CoCr alloy foil. Crystal plasticity models of the micro-specimens are developed using a length scale-dependent, strain-gradient constitutive model and a phenomenological (power-law) constitutive model, calibrated from monotonic and cyclic plasticity test data. Experimental microstructural characterisation of the grain morphology and precipitate distributions is used as input for the polycrystalline finite element (FE) morphologies. Two microstructure-sensitive fatigue indicator parameters are applied, using local and non-local (grain-averaged) implementations, for the phenomenological and length scale-dependent models, respectively, to predict fatigue crack initiation (FCI) in the HCF experiments.
| Original language | English |
|---|---|
| Pages (from-to) | 244-260 |
| Number of pages | 17 |
| Journal | Journal of the Mechanical Behavior of Biomedical Materials |
| Volume | 46 |
| DOIs | |
| Publication status | Published - 1 Jun 2015 |
Keywords
- CoCr alloy
- Crystal plasticity
- Finite element
- High cycle fatigue
Authors (Note for portal: view the doc link for the full list of authors)
- Authors
- Sweeney, CA,O'Brien, B,Dunne, FPE,Mchug, PE,Leen, SB
