Multi Response Optimization of Process Parameters in PCM of Inconel 600 Using Desirability Function Approach of RSM

An attempt has been made to apply the multi response optimization using desirability function concept for optimizing the etching conditions (etchant concentration, etchant temperature and etching time) on machining responses i.e. material removal rate, surface roughness, undercut and etch factor while photochemical machining of Inconel 600. The etching performance for Inconel 600 has been evaluated with different condition as per Face Central Composite Design of Response Surface Methodology. The mathematical models for each response have been developed using second order regression analysis. Key parameters and their interactive effect on each response have also been presented in graphical contours. The optimization of parameters has been done for machining with this non-conventional process using the desirability function concept with a target of high etchant concentration and etchant temperature. The aim is to maximize the responses i.e. material removal rate (MRR), etch factor and minimize the response i.e. surface roughness, undercut. Using this criteria, the optimum condition has been arrived for maximum MRR with etchant temperature 65°C, etchant concentration 700 gm./lit and etching time 70 min. Using the same procedure, the desirability function values of surface roughness, undercut and etch factor comes around 94%, 91% and 77% respectively.