CoCrWCu alloy with antibacterial activity fabricated by selective laser melting: Densification, mechanical properties and microstructural analysis

In the study, self-developed CoCrWCu gas-atomized powders with antibacterial activity were fabricated and used in selective laser melting (SLM). To determine whether a reliability of the SLMed CoCrWCu alloy for dental application could be obtained by using those powders, processing optimization was conducted to maximize density. Surface analysis and tensile tests were performed to verify an optimal processing parameter for fabrication of nearly full density alloy with few pores. Based on tailored parameter variation studies, a highly dense CoCrWCu alloy with 99.74% relative density could be fabricated at the energy input of 53.14 J/mm(3). The outcome from tensile test suggested that the SLMed CoCrWCu alloy met the standard of ISO 22764 for dental restorations. SEM observation showed that an extremely fine microstructure with cellular and columnar structures was obtained in the SLMed CoCrWCu alloys. As such, a large density of bar-like precipitates was found to exist, which Were confirmed to be sigma phase from the indexation of fast Fourier transform pattern. The preliminary antibacterial test indicated that the SLMed CoCrWCu alloy has an excellent antibacterial performance against E. coli. It was considered that the energy input of 53.14 J/min(3) was promising candidate for fabricating the dense CoCrWCu alloy with acceptable properties and part reliability. Also, this study can thus aid in a further improvement of CoCrWCu powders. (C) 2017 Elsevier B.V. All rights reserved.