The corrosion behavior of Ti6Al4V fabricated by selective laser melting in the artificial saliva with different fluoride concentrations and pH values

Highlights: • The critical NaF concentrations of SLM Ti6Al4V are determined. • The compositions of repassive films are analyzed. • SLM Ti6Al4V exhibits worse corrosion resistance than wrought sample. The corrosion behavior of the SLM and wrought Ti6Al4V are comparatively investigated. The critical NaF concentrations of SLM Ti6Al4V in the three cases of pH = 2, 4 and 6 are 0.0020 M, 0.080 M and 0.10 M, respectively, which are similar to those of the wrought sample. The repassivation process occurs when NaF concentrations are much larger than the critical values. The crystallinity and the Al and F contents decrease when the NaF concentration and pH value rise. As compared to the wrought Ti6Al4V, the SLM sample exhibits significantly worse corrosion resistance in almost all the test solutions.