Experimental Study of Micromachining on Borosilicate Glass Using CO2 Laser

Laser beam machining (LBM) is a versatile process that can shape a wide range of engineering materials such as metals, ceramics, polymers, and composite materials. However, machining of glass materials by LBM is a challenge as most of the laser energy is not absorbed by the surface. In this study, an attempt has been made to increase the absorptivity of the glass material by using a coating on the surface of the material. Glass has been used in this study because of its extensive applications in the micro-opto-electro-mechanical systems. The optimal machining depends on both laser parameters and properties of the workpiece material. There are number of laser parameters that can be varied in the laser machining process. It is difficult to find optimal laser parameters due to the mutual interaction of laser parameters. A statistical study based on design of experiment (DoE) has been made to study the effect of coating and parameters like laser power, laser scanning speed, angle of inclination of the workpiece on depth of the slot, width of the slot, aspect ratio, and material removal rate (MRR) in the laser machining process using 2(k) factorial design and analysis of variance (ANOVA). On an average, four times increase in depth of the slot, two times increase in width of the slot and seven times increase in the MRR were observed in the glass samples with coating when compared to uncoated glass work samples.