Process parameters selection for laser polishing DF2 (AISI O1) by Nd:YAG pulsed laser using orthogonal design

Abstract

Mechanisms of laser polishing metals in a continuous scanning mode, as envisaged and analyzed in this paper, are rather complex, and experimental optimization of laser polishing metallic material is very timeconsuming and difficult. Aiming at shortening the experimental time in achieving a better surface finishing of DF2 (AISI 01) tool steel by pulse Nd:YAG laser, we used the orthogonal experimental design for selecting the laser operational parameters. The results showed that the orthogonal design (OD) allowed the optimum technological parameters for the laser polishing to be obtained quickly and effectively. According to the OD analysis and experimental data, the attainable optimum laser smoothening/polishing parameters from this study are pulse energy (P)=1 J, feed rate=300-400 mm/min, pulse duration=3 ms, and pulse frequency (f)=20-25 Hz. The work in this paper demonstrates the relative superiority of orthogonal design in saving experimental times and providing good laser polishing surface in surface texturing and the smoothening process.

Laser polishing of 3D printed mesoscale components

“…The effects of process parameters such as energy density [17][18][19], scanning speed [20] and step-over distance [21] on the quality of laser polished surfaces have been studied by numerous researchers, with the majority concluding that laser energy density has the strongest influence on resulting surface integrity [19]. Laser energy density is typically controlled by varying the focal offset distance (FOD) from the workpiece, which correspondingly alters the diameter of the beam.…”

A Review of Post-Processing Technologies in Additive Manufacturing

“…For example, Mai and Lim [118] applied laser polishing to reduce the roughness of 304 stainless steel from 195 nm to 75 nm, consequently increasing surface reflectivity to 14% and reducing diffusion reflectivity to 70%. Guo et al [119] investigated polishing results in AM processes, showing that the roughness value decreased from 0.4 µm to 0.12 µm. Lamikiz et al [120] claimed that the hardness of a laser polishing processed surface was slightly higher and more uniform than other surfaces, with almost no cracks or HAZ.…”

Review on mechanism and process of surface polishing using lasers

“…Feed rate in lasers means pulses per millimeter. The peaks on the metal surfaces are removed using the laser irradiation where an improper speed can result in a rough surface instead of a smoother one [48]. Previous works showed that higher feed rates above a certain limit lead to a rougher surface and poor surface finish which is evident from Fig.…”