Mechanische und tribologische Eigenschaften von hochstickstoffhaltigen Austeniten

Abstract

Austenitic stainless steels provide a fair combination of strength, toughness and corrosion resistance. Undergoing tribological stresses -in particular under self-mating contact situations -their performance is not sufficient. Thus the more wear resistant austenitic Co-base alloys with different carbon contents are applied under these circumstances, which may prevail in medical applications. Austenitic high-Nitrogen Steels might be an alternative under these circumstances. Strength, corrosion resistance and tribologcial properties are similar to those of CoCrMo-alloys, while their toughness is higher. This contribution presents the metallurgical mechanisms, which bring about this combination of properties.

Subsurface changes of a MoM hip implant below different contact zones

“…Furthermore, Rigney and Glaeser (1978) and Rigney (2000) has shown by large-scale molecular dynamics simulations of sliding that with the right extent of strain rate a nano-crystalline structure will be produced. Fischer et al (2006) have shown that the formation of this nano-crystalline structure together with a low stacking fault energy are the key factor for the great wear performance of this cobalt-chromium alloy. The production of wear debris takes only place in this layer of nano-crystals with the result of nanometer-sized wear particles and an overall lower volumetric wear rate.…”