Effect of single pulsed picosecond and 100 nanosecond laser cleaning on surface morphology and welding quality of aluminium alloy. (July 2020)

• Record Type: Journal Article
• Authors: Zhou, Cong; Li, Honggeng; Chen, Genyu; Wang, Gang; Shan, Zizhao
• Is Part Of: Optics & laser technology. Volume 127(2020)
• Publication Date: 2020-07
• Subjects: Picosecond laser -- Laser cleaning -- Surface micromorphology -- Process strategy -- Welding quality; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2020.106197
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Picosecond laser cleaning 5A06 Aluminium alloy can achieve higher surface quality. Picosecond laser has higher area and volume cleaning efficiency. Laser cleaning reduces the oxygen content on the surface of aluminium alloys. Laser cleaning before welding can significantly reduce the porosity of the weld. Abstract: Removing the oxide film and dirt on the surface of the aluminium alloy can improve the welding quality of the aluminium alloy. In this paper, the characteristics of picosecond and 100 nanosecond pulsed laser cleaning aluminium alloys are explored by changing the average laser power, spot overlap ratio and scanning trajectory overlap rate. The results show that the oxide laser removal depth and diameter are related to the average power. As the average laser power increases, the depth and diameter of the ablation pit increase. At the same average power, the nanosecond laser ablation depth is greater than the picosecond laser. To achieve good surface quality, the nanosecond laser requires a higher overlap rate than the picosecond laser. The high overlap rate results in a nanosecond laser cleaning efficiency that is much lower than that of a picosecond laser. More importantly, the surface quality obtained by picosecond laser cleaning is much better than nanosecond laser cleaning. In addition, the welding experiment shows that the laser cleaning pre-treatment can effectively improve the welding quality.