Microstructure and electrochemical corrosion behavior of selective laser melted Ti-6Al-4V alloy in simulated artificial saliva

Ti-6Al-4V alloy was fabricated via selective laser melting (SLM) to improve its corrosion resistance for implant. The microstructure and electrochemical corrosion behavior were investigated using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), electrochemical test and contact angle test. It can be found that the as-selective laser melted (as-SLMed) Ti-6Al-4V alloys show beta columnar microstructure in building direction and nearly circular checkerboard microstructure in scanning direction, while the wrought and wrought+HT samples exhibit equiaxed microstructure. The as-SLMed Ti-6Al-4V alloy exhibits better corrosion resistance than the wrought and wrought+HT samples due to hydrophobicity, high grain boundary density and uniform distribution of alloying elements in simulated artificial saliva at 37 degrees C.