Manufacturing Technology Today

M. R. Dhanvijay ¹, B. B. Ahuja ¹

Affiliations
1 Department of Production Engineering and Industrial Management, College of Engineering, Pune [COEP], Wellesley Road, Shivajinagar, Pune, Maharashtra, IN

Abstract

Electrochemical discharge machining is a non-conventional machining technique for machining electrically non-conducting materials like glass, quartz, ceramics, and composites. Spark generation and control of gas bubbles around the tool has been a major problem in many researches. This work aims towards possibility of improving the material removal rate (MRR) and reduction of diametric over cut (DOC) by adding graphite powder to the electrolyte. The most effective values for machining parameters have been analyzed using the Taguchi S/N ratio analysis. Maximum MRR is obtained at high level of applied voltage, duty factor and concentration of electrolyte and moderate level of concentration of powder. Similarly the minimum DOC is obtained at low level of applied voltage and duty factor and moderate level of concentration of electrolyte and concentration of graphite powder between 3- 4 wt%. Confirmation test with optimal level of process parameters is carried out to validate the obtained optimum value.

Keywords

ECDM, Powder-Mixed ECDM, Graphite Powder, Taguchi Analysis.

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S. P. Lathkar ¹, B. Rajiv ², B. B. Ahuja ², S. K. Basu ²

Affiliations
1 MGM’S Research Centre, Nanded, IN
2 Department of Production Engineering and Industrial Management, College of Engineering, Pune, IN

Abstract

This paper presents comparative experimental study on machining characteristics of through holes (1000 micron) produced on special alloy steel, Stavax, thick plate with different types of dielectrics. Fast hole rotary Near Dry EDM (NDEDM) machine using tubular hollow brass electrodes are used for machining. Several holes are drilled using identical input parameters based on full factorial design of experiment procedure with four center points. Corresponding values of Material Removal Rate (MRR), Tool Wear Rate (TWR), MRR /TWR ratio & % Electrode Ratio are calculated and compared. The empirical relationship for above responses are developed using Regression Analysis. Surface Response Curves are plotted to compare response of interest. The results revealed that MRR,TWR & MRR/TWR (λ) ratio depends up on appropriate selection of input parameters as well as selection of dielectric.

Keywords

Near Dry Electro Discharge Machining (NDEDM), MRR, TWR, Surface Response Curves.

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Arati Mulay ¹, B. B. Ahuja ¹

Affiliations
1 Production Engg Dept, College of Engineering, Shivajinagar, Pune, IN

Abstract

In the current scenario of rapid product development, laser scanners are widely used owing to fast measurement technique as compared to continuous contact scanners. For reverse engineered products direct generation of STL file using digitized point cloud data reduces time and error during the modelling process. In case of continuous contact scanners, after removing the noise, data can be arranged into matrix format. After this, matrix triangulation method can be used to convert point cloud data into STL file, without generating a surface model. A reduction in the number of point data is important while digitizing the object using laser scanners as data obtained is tremendous, which is not useful for perfect triangulation. And improper triangulation ultimately results in a STL file containing gaps or intersecting surfaces. To overcome this problem a new methodology "Row-Column" method is suggested for data reduction as also data can be arranged in a row and column wise format, so that matrix method of triangulation can be used. A case study is presented along with the validation procedure for generated STL file.

Keywords

Rapid Prototyping, Reverse Engineering, Matrix Method of Triangulation, Row-Column Method.

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N. R. Rajhans ¹, B. B. Ahuja ²

Affiliations
1 Viswakarma Institute of Technology, Pune - 411037, IN
2 Pune Institute of Engineering and Technology, Pune - 411005, IN

Abstract

Although there are different methodologies available to design a layout namely cell formation, PFA with REL Chart, dependency matrix; it is difficult to apply these techniques universally. Each situation presents a typical problem where the existing technologies fail to give satisfactory results. In this paper an attempt has been made to design a mixed layout (partly cellular and partly straight-line). The layout is derived from dependency matrix and dependency network.

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J. K. Bagwan ¹, M. N. Shaikh ¹, B. Rajiv ¹, B. B. Ahuja ¹

Affiliations
1 Dept of Production Engg & Industrial Management, College of Engineering, Pune, IN

Abstract

The present experimental investigations are to evaluate the machinability of cryogenically treated AISI M2 HSS with copper as Tool in EDM process. The Experiments are performed to study the effects of input parameters such as Discharge current, Pulse on time, Duty cycle and Gap voltage on MRR, TWR and Radial overcut. Nowadays use of cryogenic treatment in machining is increasing day-by-day because the properties necessary for Tool we get after cryogenic treatment, except impact strength. After Cryogenic treatment there is improvement in the properties of the material such as electrical properties, thermal properties, brittleness and hardness. In this present investigation deep cryogenic treatment was done at -185°C for 36 hours on work piece (AISI M2 HSS) without tempering. Compared to conventional tool and work piece, the cryogenically treated work piece shows average increase 3.56% in MRR, the TWR is about 12.76%. The Radial overcut for cryogenic treated work piece is more than conventional EDM. The SEM images shows that machined surface of conventional EDM surface is better than cryogenically treated work piece.

Keywords

EDM, Deep Cryogenic Treatment, MRR, TWR, RSM.

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