Defined surface adjustment for medical magnesium implants by electrical discharge machining (EDM) and plasma electrolytic oxidation (PEO)

For the successful implementation of bio-degradable magnesium implants in medicine, a defined corrosion behaviour according to the bone growth needs to be established. While conventional concepts focus on a defined adaptation of the base alloy composition, the presented approach focusses on a defined macro- and microstructuring of the implant. This includes both, a defined surface enlargement and conversion by surface modification as well as the realization of inner channels for ingrowth achieved by a process combination of plasma electrolytic oxidation (PEO) and electrical discharge machining (EDM). Resulting surface characteristics as well as in-vitro behaviour have been comprehensively analyzed and preliminary in-vivo results are given.