Applied Sciences, Vol. 13, Pages 6276: Effect of Laser Treatment on Intrinsic Mechanical Stresses in Titanium and Some of Its Alloys

Applied Sciences, Vol. 13, Pages 6276: Effect of Laser Treatment on Intrinsic Mechanical Stresses in Titanium and Some of Its Alloys

Applied Sciences doi: 10.3390/app13106276

Authors: Magdalena Jażdżewska Michał Bartmański Andrzej Zieliński Dominika Beata Kwidzińska

Laser surface treatment conducted at different power levels is an option to modify titanium bone implants to produce nano- and microtopography. However, such processing can lead to excess mechanical stress within the surface layer. This research aims to calculate the level of such residual stresses after the surface processing of Ti grade IV, Ti15Mo, and Ti6Al7Nb alloys with an Nd:YAG laser. Light and scanning electron microscopies (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), optical profilography, and nano-indentation tests were applied to characterize the surface zone. The laser processing resulted in a distinct surface pattern and the formation of remelted zones 66–126 µm thick, with roughness values ranging between 0.22 and 1.68 µm. The mechanical properties were weakly dependent on the material composition. The residual stresses caused by the laser treatment were moderate, always tensile, increasing with loading, and was the highest for the Ti15Mo alloy.