Author Affiliations
Abstract
1 College of Material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
2 Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA
3 Key laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education, Taiyuan 0300 24, China
We investigate the influence of environmental media on ablation rate of AISI 443 stainless steel under femtosecond (fs) laser single raster scan and multiple raster scans in air, water, and methanol. Meanwhile, the development of ablation rate with the change of fs laser-induced surface morphology in the three environmental media is comparatively studied. The results show that environmental media as well as fs laser-induced morphology control the ablation rate with the increasing number of raster scans (N). Under single raster scanning (N = 1), the ablation rate is higher in liquid than in air due to the confinement of plasma, laser-induced shockwaves, and bubble-related mechanical forces. However, under multiple raster scans, the variation in ablation rate with the increase in N in these three environmental media is complicated and is largely determined by the surface morphology induced by previous fs laser ablation. When N > 20, the ablation rate is much higher in air than in liquids due to preferential ablation caused by the formation of nanostructures-textured mound-shaped microstructures in air. Besides, the redeposition of ejected ablated materials is also an important factor that affects the ablation depth.
140.7090 Ultrafast lasers 320.2250 Femtosecond phenomena 350.3850 Materials processing 240.6700 Surfaces Chinese Optics Letters
2015, 13(1): 011402
