CO2 laser machining is an advanced material processing technology, gaining more popularity due to its low cost and rapidity as well as good cutting quality depending on the material and its properties. Polymethylmethacrylate (PMMA) is found to be one of the most suitable thermoplastics for CO2 laser machining due to its higher melting point and higher absorptivity at the CO2 laser wavelength. The kerf taper angle is one of the most important quality characteristics because it is one of the measures for the geometrical accuracy of the machined cavities. The present work deals with the CO2 laser (0–25 W) cutting of 8 mm thick PMMA material. The influence of process parameters like power, speed, and a number of passes of the laser probe is examined on the kerf taper angle. The regression analysis has been done to develop a model that studies the effect of process parameters on the kerf taper angle which is one of the important cutting quality characteristics. Experiments were carried out using the full factorial methodology, and the cylindrical blind cavities were machined for different combinations of parameters. It is found that power, speed, and a number of passes have a significant effect on the kerf taper angle. Higher laser power, lower speed, and higher number of passes of laser probe result in low kerf taper. The statistical model developed can be used for the selection of process parameters for process control.

Polymethylmethacrylate has an advantage of absorbing the maximum intensity of the radiation incident on it. This makes it suitable to be machined by a laser machining process for creating spherical and rectangular cavities. The most important parameter for achieving the required depth of the cavity is the number of passes of the laser probe along with laser power and scanning speed. This paper deals with the development of an algorithm for predicting the depth of cut for a given number of passes. Further, an attempt is made to develop an algorithm to predict a number of the laser beam passes for a required depth of cut. Both the proposed algorithms show good convergence with the experimental results. The major concern in both the proposed algorithms is the focused distance and depth of cut, which go on changing nonlinearly with an increase in the number of passes.

Emergence of advanced engineering materials, stringent design requirements, intricate shape and unusual size of workpiece restrict the use of conventional machining methods. Laser Beam Machining (LBM) is one of the advance manufacturing processes which are used for shaping almost whole range of engineering materials. The present work deals with the study of varying pressure and traverse speed by CO 2 lasers for cutting the acrylic material and the attempt is made to develop a model to predict the depth of cut for 25 watt machine. The variation pattern for cutting depth is discussed about the convergence of predicted and experimental results.

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CO2 laser material processing has become popular due to its unique advantages such as high productivity, ease of automation, non-contact processing, greater material utilization, and minimum heat-affected zone. Polymethylmethacrylate (PMMA) is found to be one of the most suitable thermoplastics for CO2 laser machining due to its higher melting point and higher absorptivity at the CO2 laser wavelength. The scope of the present work deals with geometrical error analysis during machining of the three-dimensional spherical cavity with the help of a 2D setup of the laser. The influence of process parameters like power, cutting speed, and the number of passes of laser probe on cusp height is examined. The cusp height is measured after machining equal and unequal step size on PMMA. The experiments were performed for profile controlled approach for equal step size and accuracy approach for unequal step size. An algorithm is proposed for predicting unequal step diameter with a constant value of cusp height. It was observed that higher power, lower speed, and more number of passes of laser probe leads to minimum cusp height. Hence, the proposed algorithm for predicting unequal step diameter for a constant cusp height leads to a reduction in staircase effect, thereby, producing a smoother curve as compared to the profile controlled (equal step diameter) approach.