Experimental investigation and mathematical modeling of laser marking two-dimensional barcodes on surfaces of aluminum alloy

Abstract

This paper investigates the effects of laser processing parameters (fill spacing, current intensity, laser scanning speed, pulse frequency) on the quality of the barcodes laser marked on the surfaces of aluminum alloys using a Q-switched lamp-pumped Nd:YAG laser. For objective assessment of a legible barcode, the qualities of a barcode were characterized by processing quality (surface roughness) and image quality (grades assessed conforming to the international standard ISO/IEC 16022), respectively. Several single-factor experiments were carried out to investigate the influences of processing parameters on processing quality. Additionally, the relations between surface roughness and final grades were analyzed. The results indicated that the processing parameters affect the surface roughness significantly in different intervals. Two kinds of scannable barcodes were produced with ‘black’ and ‘white’ colors. The Taguchi method was used to determine the optimum process conditions to produce a scannable barcode. Furthermore, a non-linear regression model was established to formulate the relationship between the processing parameters and surface roughness. The verifying experiment shows that the obtained results from the mathematical model closely correlate with the experimental results, which proves that the prediction model performed satisfactorily.