Parametric study of laser cutting of glazed ceramic tiles

Excellent mechanical and physical properties like high thermal resistance, high hardness, and chemical stability have encouraged the use of ceramics in various applications such as automotive engines, electronic substrates for microwave devices, dielectric materials, etc. The hard and brittle nature of these ceramics makes them difficult to cut using conventional machining due to large cutting forces as well as severe tool wear involved for such hard-to-cut material. Thus, non-contact laser machining is suitable to cut the hard and brittle ceramics. A highly focused laser beam strikes the workpiece with a high energy such that the temperature of the workpiece exceeds its boiling temperature, resulting in vaporization and ablation. In this paper, an experimental investigation of the laser cutting of 7 mm thick ceramic panels, commonly used as glazed floor tiles, is carried out using a fiber laser. The present study involves a systematic experimental investigation with the aim of evaluating the influence of the input process parameters, namely laser power, frequency, scanning speed and gas pressure on kerf widths on the top and bottom surfaces, glass formation width on the bottom surface and taper angle. Based on the experimental results, regression equations are developed to estimate the responses as functions of the laser process parameters and gas pressure. Investigations reveal that kerf widths on the top and the bottom surfaces, glass formation width, and taper angle increases with laser power and decreases with increasing scanning speed at constant gas pressure and frequency. Moreover, glass formation width increases with increasing frequency at constant laser power and gas pressure, decreases with increasing frequency at constant scanning speed and gas pressure. The optimum process parameters are also found based on minimizing the taper angle at relatively low operating energy cost by minimizing the line energy, i.e., by minimizing laser power, P and maximizing scanning speed, V.