Electrochimica Acta, Vol.283, 1482-1489, 2018
Distinction in anodic dissolution behavior on different planes of laser solid formed Ti-6Al-4V alloy
Microstructure, electrochemical impedance, and Tafel and potentiodynamic polarizations were characterized to investigate the electrochemical anodic dissolution behavior of Ti-6A1-4V alloy produced by the laser solid forming (LSF) additive manufacturing process with a specific focus on the distinction on different planes. Electrochemical measurements show that the anodic dissolution characteristic of LSFed Ti-6Al-4V reveals anisotropic behavior on different planes. The horizontal-plane (XOY plane) is more resistant to corrosion than the vertical-plane (XOZ plane) in 15wt% NaCl solution. Additionally, the vertical-plane shows a lower initial machining potential for the process of electrochemical machining compared to the horizontal-plane. The microstructure of Ti-6Al-4V alloy deposit is composed of dominant alpha-laths and small amounts of beta phase, and its horizontal-plane has higher content of the beta phase, lower content of the alpha phase, slightly finer alpha-laths, and more uneven alpha-lath width distribution compared to the vertical-plane. These differences in the microstructural characteristics produce the distinctions observed in the electrochemical anodic dissolution behavior of LSFed Ti-6Al-4V alloy on the vertical- and horizontal-planes. (c) 2018 Elsevier Ltd. All rights reserved.
Keywords:Additive manufacturing;Laser solid forming;Titanium alloy;Anodic dissolution;Electrochemical machining