Microstructural investigation and multi response optimisation using Fuzzy-TOPSIS during the electrochemical machining of Inconel 825

摘要

Low thermal conductivity and superior mechanical properties of nickel-based superalloys make them very useful in high-temperature applications. The same properties also make them very difficult-to-cut in conventional machining. Electrochemical machining (ECM) is one of the widely used non-traditional machining processes especially used for producing intricate or complex geometry on difficult-to-machine materials. The present study investigates the effect of various process parameters on performance characteristics such as material removal rate (MRR) and surface roughness (SR) during the ECM of Inconel 825 using a copper tool. Analysis of variance (ANOVA) was employed to investigate the influence of process parameters on performance characteristics during machining. An attempt has also been made to study the microstructure of machined surface at different conditions and to correlate it with multiple performance characteristics. Moreover, Fuzzy-TOPSIS that uses closeness coefficient as performance index has been adapted to optimise various performance characteristics simultaneously and determine the optimal combination of ECM parameters.