Multi objective optimization of wedm profile machining

Abstract

newline Machining of difficult to machine materials pose a challenge in manufacturing industries owing to their greater strength and hardness. Such materials need to be machined by Non-Traditional Machining (NTM) processes like Abrasive Jet Machining (AJM), Electrical Discharge Machining (EDM), Laser Beam Machining (LBM) and Electron Beam Machining (EBM) etc. It is also required to economically machine the materials using NTM processes as the processing cost is comparatively higher than that of conventional machining processes. The quality of the components achieved in NTM processes depends on its process parameters. The optimal selection of process parameters is essential to achieve the desired output responses. The Inconel 825 alloy possesses an excellent mechanical and chemical properties at high temperatures. It has very poor thermal conductivity, high toughness, high hardness, and also has a tendency to form built up edge during machining which affects the surface integrity of the machined component. This material has excellent corrosion resistance behaviour and best suitable for tool and die making industries. The heat generated during machining affects the tool life considerably. Due to the above-mentioned factors, the Inconel 825 is categorized as a difficult to machine material and hence the NTM processes like EDM or WEDM are sought for machining this material. In this thesis, Inconel 825 alloy has been machined using Wire Electric Discharge Machining (WEDM) for two profile machining such as Taper Profile Machining (TPM) and 3D Profile Machining (3DPM) in view of optimizing its process parametersThe experimentation of TPM of Inconel 825 has been carried out with experimental runs suggested by Taguchi s L9 orthogonal array. The input machining parameters of WEDM process such as pulse on time (Ton), pulse off time (Toff), Wire Tension (WT) and Taper Angle (TA) have been considered for optimization. The output performances such as Material Removal Rate (MRR), Surface Roughness (SR) and Taper Error (TE) have been