Novel wear-resistant anti-bacterial stainless steel surfaces

Abstract

To generate a long-lasting antibacterial surface on stainless steels for demanding applications involving rubbing and wear, a novel triple-glow plasma (TGP) technology was employed to generate Ag/N co-alloying layers on AISI 316 austenitic stainless steel. The mechanical, chemical, antibacterial and tribological behaviour of the samples treated under different settings and parameters were fully characterised. It is identified that a durable antibacterial surface has been achieved using the novel TGP technology under an optimal parameters, as proved by the high hardness, low wear rate and high antibacterial efficacy. A bilayer structure composed of a thin top layer containing about 20–25% Ag embedded in N supersaturated austenite followed by a relatively thick (∼10 µm) S-phase layer was formed after Ag/N co-alloying by TGP. The silver embedded in the hard S-phase provides bactericidal activity against Gram-positive Staphylococcus aureus (S. aureus) with a reduction rate of 95% compared with the untreated stainless steel.