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Good wear resistance. The antibacterial properties of the stainless steel were still intact after test instruments had been cleaned 120 times.
About
What is the problem? Previous attempts to make stainless steel resistant to bacteria have been unsuccessful as these have involved the use of very thin implanted layers or soft polymer based coatings which have limited durability. This leads to the antibacterial properties being short lived. Our new Solution A novel plasma surface alloying technique to harden stainless steel surfaces by co-alloying with N and/or C to form a hard, wearing resistant phase and at the same time introduce bacteria-killing agents, such as Ag or Cu, into a stainless steel surface. Benefits of the new technology Wide application, including medical instruments, hospital equipment such as bed frames and trolleys, food preparation surface, knives and kitchen implements, in vitro tests show that a stainless steel surface alloyed with 50-60% copper is 99% effective against E. coli NCTC 10418 and S. epidermidis NCTC 11047 within a six-hour testing contact time, good wear resistance. The antibacterial properties of the stainless steel were still intact after test instruments had been cleaned 120 times. Background A large proportion of hospital-acquired infections (HAIs), are derived from contact transmission. This represents a massive global challenge. A novel active screen plasma (ASP) alloying technology has been developed to generate highly durable antimicrobial surfaces by combining a wear-resistant S-phase with nanocrystalline silver or copper with medical grade stainless steel. The phase constituents, microstructure, composition and surface roughness of the alloyed surfaces are fully characterised, and the surface hardness, wear resistance and antimicrobial efficiency of the treated surfaces have been evaluated. Experimental results show that the surface hardness and sliding wear resistance of medical grade 316LVM stainless steel can be effectively improved by the ASP alloying treatment. Furthermore, Ag alloyed S-phase can achieve 93% reduction in Escherichia coli (E. coli) after 6 h contact time. Therefore, the novel ASP alloying treatment can not only improve wear resistance but also confer antibacterial activity to stainless steel surfaces.