Modelling and Optimization of Cut Quality Characteristics for Pulsed Nd:YAG Laser Curved Profile Cutting of Ni-Based Superalloy Thin Sheet
A. Sharma and V. Yadava
Nickel-based superalloy sheets are widely used in aircraft and missile industries due to incomparable properties of superalloys such as high strength-to-weight ratio and corrosion resistance at elevated temperatures. Typical applications of superalloy sheets which require stringent design with exceptional good quality in manufacturing products is a challenging task. Pulsed Nd:YAG laser cutting of superalloy sheet satisfies all functional requirements vital for manufacturing such products. In the present study, effect of input process parameters (arc radius, oxygen pressure, pulse width, pulse frequency and cutting speed) on output quality characteristics such as average kerf deviation, Da, and average kerf taper, Ta, have been analysed using hybrid approach of modelling during pulsed Nd:YAG laser cutting of Ni-based superalloy sheet. The preferred operating laser cutting parameters have been obtained using grey relational analysis (GRA) coupled with entropy measurement (EM). The EM method is especially employed to compute the weights corresponding to each quality characteristic for finding the grey relational grade. The verification results show that the application of GRA coupled with EM approach has reduced Da by 30.43% from the initial value obtained from the L27 orthogonal array (OA).
Keywords: Nd:YAG laser, Ni-based superalloy, curved cut profile, Taguchi methodology, response surface methodology (RSM), grey relational analysis (GRA), entropy measurement