Enhancing the corrosion behavior of Laser Powder Bed Fusion processed CP-Ti via Ultrasonic Peening

Surface modification of metal Additive Manufacturing (AM) components has gathered a lot of interest recently. Ultrasonic Peening (UP) was employed to improve the corrosion properties of Laser Powder Bed Fusion (L-PBF) processed commercially pure titanium (CP-Ti). UP process forged the surface porosities, significantly refined the acicular martensites (α'-M) formed during the L-PBF, and homogenized the microstructure. These significantly enhanced the corrosion behavior of L-PBF processed CP-Ti, by reducing the corrosion current from 4.8 µA/cm2 to 0.72 µA/cm2 after a 3-pass UP. Accordig to the FESEM observations, the corroded surface of the 3-pass UPed sample was covered by a protective oxide film implying its uniform corrosion.