Corrosion behavior of laser additive manufactured titanium alloy

The influence of process parameters on corrosion behavior of the most widely used titanium alloy Ti6Al4V, produced using laser metal deposition process, was studied. The processing parameters scanning velocity, powder flow rate, and gas flow rate were kept at constant values of 0.005 m/s, 1.44 g/min, and 4 l/min while the laser power was varied between 0.8 and 3.0 kW. Electrochemical corrosion test was conducted on each of the samples produced at each set of processing parameters. The corrosive medium used is the solution of sodium chloride (NaCl) dissolved in deionized water. The results of this study indicate that as the laser power was increased, the corrosion behavior was found to be improved. The better corrosion resistance performance of the additive manufactured part can be attributed to the higher cooling rate that is associated with this type of manufacturing process. This high cooling rate results in the higher hardness of the deposited material when compared to the substrate which may have contributed to the improved corrosion resistance behavior.