Improved Corrosion Resistance of Selective Laser Melted Ti-5Cu Alloy Using Atomized Ti-5Cu Powder

The different types of metal powder used for selective laser melting (SLM) process would cause distinct corrosion behavior due to the uniformity of the obtained microstructure. The SLM-produced Ti-5Cu alloy using atomized Ti-5Cu metal powder (SLMed Ti-5Cu) in this work reveals a relatively uniform microstructure with overwhelming acicular / phase and shows great advantages on corrosion resistance compared with the SLM-produced Ti-5Cu alloy using the mixture powder (SLMed-M Ti-5Cu). The effect of the micro-galvanic cells decreases due to the undetectable Ti2Cu phase in the microstructure of the SLMed Ti-5Cu. An apparent passivation behavior was observed for SLMed Ti-5Cu instead of severe pitting phenomenon for the SLMed-M Ti-5Cu. The charge transfer resistance of SLMed Ti-5Cu in this work is 10.09 +/- 2.63Mcm(2), which is significantly higher than that of SLMed-M Ti-5Cu (4.76Mcm(2)). The above result indicates the atomized Ti-5Cu powder plays an important role in the formation of the uniform microstructure of SLMed product, thereby enhancing its corrosion resistance in Hank's solution at 37 degrees C.