Corrosion behavior and biocompatibility of titanium alloys for implants

Generally titanium alloys have proved to be suitable for implants, but there exist scruples concerning toxic alloying elements. Because of poor repoducibility and high expenditure the obvious ways to qualify different alloys by biocompatibility was not practicable. Therefore those properties which can be regarded as prerequisites of good biocompatibility were tested in saline solutions. These are high corrosion resistance and high resistance of the passive layers. Tests demonstrated the suitability of all alloys but no significant differences between titanium and its alloys TiAl6V4, TiAl5Fe2,5, TiAl7Mo4 and TiAl5Nb7. Surface treatment is more important than chemical composition.