In this study electrochemical behaviors of SS 316L and Co-Cr-Mo alloys were
studied using electrochemical method by potentiostat in simulated body fluid (SBF) at
pH=7.4 and 37oC in absence and presence of 7 and 12 g/dL uric acid which causes
arthritis. Corrosion parameters for two implants were calculated which include
corrosion potentials (Ecorr), corrosion current densities (icorr), cathodic and anodic Tafel
slops (bc & ba), polarization resistance (Rp) and corrosion rates (CR).
Increases uric acid in human body gives decreasing in corrosion rate for SS 316L
because of formation organometallic complexes between acid molecules and released
metal ions, but an increase in corrosion rate for Co-Cr-Mo alloy because of low affinity
of cobalt ions to formation organometallic complexes. General comparison between
two implants shows that the Co-Cr-Mo alloy has lower corrosion rate than SS 316L in
the same conditions due to Cr content. This means that using Co-Cr-Mo alloy better
than SS 316L as bioimplant.