Investigations On Performance Enhancement Characteristics Of Powder Mixed Near Dry Electrical Discharge Machining

Abstract

In this thesis a newly developed hybrid form of Electric Discharge Machining have been described newlinewhich is Powder-Mixed Near- Dry Electric Discharge machining and it would help the researchers to newlineunderstand the technique how to get better surface characteristics by utilizing minimum amount of newlinedielectric fluids. The contents of the thesis are as follows: newlineChapter 1 This chapter includes the background of electric discharge machining and its evolution in newlinemodern world. Afterwards, its principle was discussed along with material removal mechanism. newlineDetails regarding EDM machine and its components were also discussed in elaborated manner. newlineFurther advantages, limitation and application of EDM were discussed. Lastly types of EDM and its newlinehybrid forms were explained. newlineChapter 2 This chapter deals with review of the literature study conducted by researchers in field of newlineEDM and its hybrid forms. Several studies have been conducted related to surface finish, material newlineremoval rate, tool wear rate, micro-hardness and residual stress. newline.Chapter 3 This chapter includes preview of present investigation. The objectives of the present newlinestudy and scope of the problem were evaluated by reviewing the literature review critically. newlineAdditionally, problem formulation was described for the lacking information pertaining to EDM newlineprocess, thereafter the problems were described which needed to be solved through this present newlinework. newlineChapter 4 The Design of experiment was introduced in this chapter for experimentation planning. newlineFurther Taguchi methodology along with analysis of variance was studied for process optimization newlineof the developed process of Powder Mixed Near Dry EDM. This chapter also gives information newlinerelated to steps involved in Taguchi methodology and application of analysis of variation (ANOVA) newlinein various research fields. Lastly scheme of experiments has been discussed along with instruments newlineused for measurement of different response characteristics. newlineChapter 5 This chapter includes information related to Electric Discharge Machine and design of newlinepowder mixed near dry electric discharge machining (PMND-EDM) setup and it s another form of newlinegaseous assisted powder mixed near dry EDM (GAPMND-EDM) setup. The specification of the newlineused parts was defined along with the operational condition of the indigenously developed setup. newlineAfterwards, details of tool electrode fabrication and its design were also discussed. newlineiv newlineChapter 6 This chapter describes parameters selected for experimentation in powder mixed near dry newlineEDM and gaseous assisted EDM. Afterwards selection of response characteristics was elaborated. newlineVariable parameters such as tool type, metallic powder concentration, dielectric mist pressure, mist newlineflow rate, types of gases, and types of metallic powders were discussed along with their range in newlineorder to optimize the process parameters for enhancing the machining performance in terms of newlineincreased material removal rate, improved surface finish, improved micro-hardness, reduction of newlineresidual stress and tool wear rate. Lastly, the instruments used for measuring response characteristics newlinewere discussed. newlineChapter 7 This chapter includes thermal-physical based modeling for material removal in Powder newlineMixed Near-Dry Electric Discharge Machining. This research includes three-dimensional newlineaxisymmetric model for PMND-EDM. Thermal properties of material, heat source shape (Gaussian newlineheat distribution), heat distribution percentage among workpiece, tool and dielectric fluid, pulse on, newlinepulse off and material ejection efficiency were considered as significant elements for predicting the newlineMRR in PMND-EDM. newlineChapter 8 This chapter includes result and discussion related to present investigation. This section newlineincludes validation of model through experimental and analytical means. Further discussion was newlinerelated to optimization of process parameters and their effect on output performance characteristics. newlineThe best combination of the parameters was found for improving the machining efficiency. Later newlineconfirmation experiments were conducted to verify the results. Lastly analysis of machining newlineperformance was done based on gaseous assisted EDM with powder additives. newlineChapter 9 This chapter contains salient conclusions. Important conclusions of the investigation newlineregarding MRR, Ra, TWR, MH and RS are stated in this end part of the thesis. This chapter also newlineintroduces scope for further research in this field. Significant findings have been drawn from newlineperformed experimentation. newline newline