Investigation of processing parameters for three-dimensional laser ablation based on Taguchi method

Abstract

Laser ablation is a high-efficiency, high-precision, and very flexible process for removal material which has been widely used in many industrial applications, such as semiconductor, electronic, aerospace, and other fields. With the development of modern manufacturing industry, the application of laser ablation technology needs to be expanded to meet the growing demand of three-dimensional processing. A method named laser ablation by projective galvanometer scanning (LPAGS) can effectively apply laser ablation technology to three-dimensional processing field. For three-dimensional processing, the machining results are strongly affected by the processing parameters. Optimal selection of process parameters is highly critical for successful material removal and achieving high surface quality. In this paper, the effects of processing parameters including laser incident angle, scan speed, laser power, and fill spacing on ablation depth and surface roughness were studied in detail. An orthogonal experiment based on Taguchi method was used to determine the optimal processing direction for minimizing the surface roughness and maximizing the milling depth. The typical structural patterns were fabricated on surface of aluminum by using a LPAGS processing system. Signal/noise ratio (S/N ratio) and analysis of variance (ANOVA) were employed to investigate the optimal levels of processing parameters. The analysis results indicated that laser incident angle and laser power have significant effect on the ablation depth with 48.02 and 39.67% contribution, and laser incident angle, laser power, and scan speed are most significant parameters with 40.88, 24.66, and 30.16% contribution on surface roughness.