Effect of Laser Energy Density on Surface Morphology, Composition and Cleaning Mechanism of TC1 Titanium Alloy During Nanosecond Laser Cleaning

To remove the oxide layer of TC1 titanium alloys in an environmentally friendly and efficient manner, this study conducted experiments using a nanosecond pulsed laser to systematically investigate the influence of different laser energy densities on the cleaning effect. The results showed that the oxide layer could be completely removed at an energy density of 6.37 J/cm2, with the surface oxygen element content reduced to 4.87%. The macroscopic surface presented a silvery metallic luster. Moreover, the roughness decreased significantly with the increase in energy density. At 6.37 J/cm2, the surface roughness dropped to 0.37 µm. The mechanism of removing the oxide layer of TC1 titanium alloy mainly includes laser ablation and plasma impact. At energy densities ranging from 2.55 J/cm2 to 6.37 J/cm2, the cleaning mechanism was mainly laser ablation. When the energy density exceeded 6.37 J/cm2, the cleaning mechanism gradually shifted from laser ablation to plasma impact as the dominant factor. Meanwhile, the microhardness of the samples after laser cleaning was basically consistent with that of the samples subjected to mechanical grinding, which provides a basis for a nanosecond pulsed laser to replace traditional methods for oxide layer cleaning.