As orthopaedic implant manufacturers improve longevity of hip and knee prostheses, new coatings are being developed to minimize in-vivo wear against a polyethylene bearing.  In this investigation, a multilayer coating consisting of chemical vapor deposition Al₂O₃/TiCN/TiN on a Co-28Cr-6Mo implant substrate is evaluated in terms of corrosion resistance of its components in undamaged and scratch-damaged conditions.  Potentiodynamic and potentiostatic measurements performed in Hanks salt solution with 25% bovine serum at 37°C, followed by sample sectioning, suggest that at potentials up to +2.2 V (vs. Ag/AgCl), the Co-28Cr-6Mo substrate is more susceptible to dissolution than the Al₂O₃, TiCN and TiN components.  Cyclic scans performed on scratched CVD alumina coating and scratched oxidized Zr-2.5Nb at potentials of +1.1V (vs. Ag/AgCl) exhibit no hysteresis characteristic of crevice corrosion.  Potentiostatic testing of scratched CVD alumina coating and scratched oxidized Zr-2.5Nb at +0.5V and +1.0V (vs. V_oc) for 72 hours reveal current decrease to approximately 1 nA.