|About this Abstract
||Materials Science & Technology 2011
||MS&T'11 Poster Session
||002 A Quantitative Method to Assess Free Iron Removal after Passivation
||Sophie Xiaofan Yang, Lakshmi Sharma, Bernice Aboud
|On-Site Speaker (Planned)
||Sophie Xiaofan Yang
Removal of exogenous iron or iron contaminants from machined or polished surfaces of metallic medical devices is done by chemical dissolution in an acid solution, for the purpose of forming a protective passive film. Test methods used to determine if the ‘free iron’ has been removed are subjective, as it is unknown how much, or if any Fe is even present prior to testing. A quantitative method was required in order to equally compare the effectiveness of the trending citric acid passivation vs. nitric acid passivation. A novel method was developed by agitating polished disks (Ti6Al4V, CoCrMo) with 1mm steel shot in a Turbula shaker for a set time. Energy Dispersive Spectroscopy mapping and X-ray Photoelectron Spectroscopy were used to quantify Fe in each uniquely identified disk before and after passivation. A 2-Level DOE determined which time, temperature and concentration of citric acid and nitric acid passivation was more effective.