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Prediction and Experimental Validation of Laser Parameters for Fabrications of A Microchannel

Corresponding Author : Mst. Nasima Bagum (nasima-ipe@sust.edu)

Authors : Mst. Nasima Bagum (nasima-ipe@sust.edu), Choudhury Abul Anam Rashed (rashed-ipe@sust.edu), Md. Mehedi Hasan Kibria (kibria-ipe@sust.edu), Md. Ahsan Habib (ahsan43@student.sust.edu), Maaroof-Ul Alam (maaroof17@student.sust.edu)

Keywords : Threshhold energy, Finite element analysis, Microchannel, Heat loss, Track shape

Abstract :

Laser beam machining is an effective technology used across industries due to its diverse applications. Laser engraving processes workpieces through chemical ablation, melting, blowing, and evaporation. Identifying the right process parameters to achieve the desired outcome remains a significant challenge. This research identifies the threshold energy and finds the amount of laser energy that does not contribute to material removal by combining finite element analysis (FEA) and the theoretical model. It also predicts the depth and width of the engraving and compares it with the experimental result. FEA analysis revealed that the PMMA sheet starts to melt when the power and the scanning speed ratio is 0.013. However, experimental results found that this ratio is 0.0156; hence, almost 32.67 % of laser energy is lost. Based on the threshold power, the depth and width of the microchannel were calculated using a theoretical model. A microchannel was imprinted on 11 workpieces using a 120 W CO2 pulse laser, and the depth and width were measured using a Celestron Microscope. The effects of process parameters are analyzed by observing the microscopic image of the workpiece and by plotting all experimental and FEA outputs. It shows the depth and width increase with the power increase and the scanning speed decrease. The theoretical depth data match well with experimental results at a higher power-to-speed ratio, and the shape of the groove is smooth with a wide V shape at this ratio. However, the relation between the power-to-speed ratio and width is nonlinear, and beyond the power-to-speed ratio of 0.72, the theory overpredicts the width. 

Published on March 28th, 2025 in Volume 5 (Special Issue), Mechanical, Manufacturing & Industrial Engineering