Multi-objective optimization of Nd:YAG laser cutting of nickel-based superalloy sheet using grey-fuzzy approach

A nickel-based superalloys sheet finds its applications in many industries. Laser cutting of these alloy sheets are very important from the quality point of view. Thus, it is important to have an optimal combination of parameters in order to achieve quality responses. Keeping this in view, grey relation analysis (GRA) aided with fuzzy logic is applied for multi-objective optimization of Nd:YAG laser beam cutting (LBC) of nickel-based superalloy (SUPERNI 718) sheet. The input parameters considered for this process are assist gas pressure, pulse width, pulse frequency, and cutting speed to optimize response parameters considered as kerf width, kerf deviation and kerf taper. The result found using this approach shows that for optimal response the input parameters need to be set as gas pressure at 2kg/cm², pulse width at 0^s, pulse frequency at 23Hz, and cutting speed at 20mm/min. The optimal parametric mix found using our approach is similar to that found by the previous researchers, which is also supported by technique for order preference by similarity to ideal solution (TOPSIS). Analysis of variance is also applied to identify the significance of each process parameters in the laser cutting process. (paper)