Improvement of Surface Mechanical and Tribological Characteristics of L-PBF Processed Commercially Pure Titanium through Ultrasonic Impact Treatment

Multi-pass ultrasonic impact treatment (UIT) was applied to modify the microstructure and improve the mechanical and tribological characteristics at the near-surface region of commercially pure Ti (CP-Ti) specimens produced by the laser powder bed fusion (L-PBF) method. UIT considerably refined the L-PBF process-related acicular martensites (α′-M) and produced a well-homogenized and dense surface microstructure, where the porosity content of 1-, 3-, and 5-pass UITed samples was reduced by 43, 60, and 67