Simultaneous optimisation of average kerf taper and surface roughness during pulsed Nd: YAG laser cutting of thin Al-alloy sheet for straight profile

摘要

This paper presents an application of doe-based hybrid approach for the determination of preferred operating laser cutting parameters which minimises the average kerf taper (T_a) and average surface roughness (R_a) together during pulsed Nd: YAG laser cutting of thin aluminium alloy sheet for straight profile. The hybrid approach, comprises of Taguchi methodology (TM) and response surface methodology (RSM), has been applied to achieve the better cut qualities within the existing resources. The input process parameters taken are oxygen pressure, pulse width, pulse frequency and cutting speed. The approach first uses the Taguchi quality loss function to find the optimum level of laser cutting parameters. The optimum values of input cutting parameters so obtained are further used as a central value in RSM. Further, the experiments are conducted by using the central composite rotatable design (CCRD) matrix. Subsequently, the laser cutting parameters have been optimised by using the MINITAB software. The application of hybrid approach has reduced T_a by 15% whereas it has been reduced by 6.7% with the application of TM only.