Pulsed Nd:YAG laser turning of micro-groove on aluminum oxide ceramic (Al2O3)

The present study investigates the relationship of processes parameters of pulsed Nd:YAG laser-turning operation for production of micro-groove on cylindrical workpiece of ceramic material. A microprocessor-based work holding device has been developed to provide the rotational motion of cylindrical work pieces for micro-turning operation. Laser turning of micro-grooves on ceramics is highly demanded in the present industry because of its wide and potential uses in various fields such as automobile, aerospace and bio-medical engineering applications, etc. Experiments have been conducted on laser micro-grooving of aluminum oxide (Al2O3). The central composite second-order rotatable design (CCD) had been utilized to plan the experiments and response surface methodology was employed for developing empirical models. Analysis on machining characteristics of pulsed Nd:YAG laser micro-grooving operation was made based on the developed models. In this study, lamp current, pulse frequency, pulse width, assist air pressure and cutting speed of work piece are considered as laser machining process parameters. The process performances such as upper deviation (Yuw), lower deviation (Ylw) and depth (Yd) characteristics of laser-turned micro-grooves produced on cylindrical work piece made of Al2O3 were evaluated. Analysis of variance (ANOVA) test had also been carried out to check the adequacy of the developed regression empirical models. The observed optimal process parameter settings are lamp current of 22.517 A, pulse frequency of 1.477 kHz, pulse width of 2.394% of duty cycle, cutting speed of 10.4283 rpm and assist air pressure of 1.3 kgf/cm2 for achieving minimum upper deviation, lower deviation and depth of laser-turned micro-grooves, and finally the results were experimentally verified. From the analysis, it was found that proper control of the process parameters lead to achieve minimum upper deviation, lower deviation and depth of laser-turned micro-grooves produced on cylindrical workpiece of Al2O3.