A Comparison of Generator Mode on the Performance of Finish EDM of AISI P20 Tool Steel

Author(s):  
Fred L. Amorim

The AISI P20 steel is applied by the tooling industry as material for injection molding tools. It is known that the EDM process parameters technology installed at the majority of CNC EDM machines do not cover some of the necessities of the tooling industry. So, the customers are required to develop their own process parameters. In order to provide useful technical information to the industry an experimental investigation on the EDM of the AISI P20 tool steel under finish machining has been carried out. The material removal rate Vw, volumetric relative wear v and workpiece surface texture Ra, which are representative of EDM performance aspects, were analyzed against the variation of some of the most important EDM electrical variables using copper tool electrodes under positive and negative polarity. The EDM machine generator was also programmed to actuate under isoenergetic mode and relaxation mode. The results are discussed and some appropriate parameters for EDM of AISI P20 are suggested.

Manufacturing ◽  
2003 ◽  
Author(s):  
Scott F. Miller ◽  
Albert J. Shih

The development of new, advanced engineering materials and the needs for precise and flexible prototype and low-volume production have made wire electrical discharge machining (EDM) an important manufacturing process to meet such demand. This research investigates the effect of spark on-time duration and spark on-time ratio, two important EDM process parameters, on the material removal rate (MRR) and surface integrity of four types of advanced material: porous metal foams, metal bond diamond grinding wheels, sintered Nd-Fe-B magnets, and carbon-carbon bipolar plates. An experimental procedure was developed. During the wire EDM, five types of constraints on the MRR due to short circuit, wire breakage, machine slide speed limit, and spark on-time upper and lower limits have been identified. An envelope of feasible EDM process parameters is created and compared across different work-materials. Applications of such process envelope to select process parameters for maximum MRR and for machining of micro features are presented.


Author(s):  
Shivraj Yeole ◽  
Nagabhushana Ramesh Nunna ◽  
Balu Naik Banoth

Electrical Discharge Micro Drilling (EDMD) is considered as one of the most effective method for machining difficult to cut and hard materials like titanium alloy. However, selection of process parameters for achieving superior surface finish, higher machining rate and accuracy is a challenging task in drilling micro-holes. In this paper, an attempt is made to optimize micro-EDM process parameters for drilling micro holes on titanium grade 19 alloy. In order to verify the optimal micro-EDM process parameters settings, material removal rate (MRR), electrode wear rate (EWR) and over cut (OC) were chosen as the responses to be observed. Pulse on time, pulse off time, electrode diameter and current were selected as the governing process parameters for evaluation by Taguchi method. Nine micro holes of 300 μm, 400 μm and 500 μm were drilled using L9 orthogonal array (OA) design. Optimal combination of machining parameters were obtained through Signal-to-Noise (S/N) ratio analysis. It is seen that machining performances like material removal rate and overcut are affected by the peak current whereas electrode wear is affected by peak current and electrode diameter. Morphology of the micro holes has been studied through SEM micrographs of machined micro-hole.


2020 ◽  
Vol 978 ◽  
pp. 271-276
Author(s):  
Sahini Deepak Kumar ◽  
Shailesh Dewangan ◽  
Joyjeet Ghose ◽  
S.K. Jha

The present work reports the influence of various Electric-Discharge Machining (EDM) process parameters on the surface morphology and EDM characteristics of thixoformed A356-5TiB2 in-situ composites. The important EDM parameters such as pulse current, pulse-on time, Duty Cycle, etc. on Surface morphology and Material removal rate of the thixoformed A356-5TiB2 in-situ composites have been investigated. Further, the machining parameters were optimized using Fuzzy-logic and grey relational analysis approach. The effect of EDM parameters and their interactions on the erosion behavior of A356-5TiB2 in-situ composites on various aspects of surface integrity and Material Removal rate (MRR) is reported. The surface integrity during EDM was characterized by Scanning Electron Microscope and analyzed from the machinability point of view. Thus, this work is an attempt to study the machinability behavior of thixoformed A356-5TiB2 in-situ composites.


2018 ◽  
Vol 28 ◽  
pp. 55-66 ◽  
Author(s):  
Kuldeep Singh ◽  
Khushdeep Goyal ◽  
Deepak Kumar Goyal

In research work variation of cutting performance with pulse on time, pulse off time, wire type, and peak current were experimentally investigated in wire electric discharge machining (WEDM) process. Soft brass wire and zinc coated diffused wire with 0.25 mm diameter and Die tool steel H-13 with 155 mm× 70 mm×14 mm dimensions were used as tool and work materials in the experiments. Surface roughness and material removal rate (MRR) were considered as performance output in this study. Taguchi method was used for designing the experiments and optimal combination of WEDM parameters for proper machining of Die tool steel (H-13) to achieve better surface finish and material removal rate. In addition the most significant cutting parameter is determined by using analysis of variance (ANOVA). Keywords Machining, Process Parameters, Material removal rate, Surface roughness, Taguchi method


2013 ◽  
Vol 441 ◽  
pp. 7-10
Author(s):  
Shih Hung Tai ◽  
Chun Yao Hsu ◽  
Ching Hung Su ◽  
Ching I Lin

This study investigates the optimization of micro milling EDM process parameters to achieve multiple performance characteristics (low electrode depletion (ED), high material removal rate (MRR) and low overcut) in the Inconel 718 by the Grey-Taguchi method. Experimental results show that the electrode depletion decreased from 0.56 to 0.52 10-8 mm3/min, the material removal rate increased from 0.47 to 1.68 10-8 mm3/min and the overcut decreased from 1.27 to 1.19 μm under optimal micro milling EDM process parameters. Furthermore, control charts tell us when special causes of variation are impacting machining process. Control charts are basic and powerful tools in statistical process control and are widely used to control various industrial processes. The aim of statistical process control is to explore the predictability of a process. It was found that the EDM process and product characteristics are stable over time.


Author(s):  
Satish Giduturi ◽  
Ashok Kumar

Wire Electrical Discharge Machining (WEDM) is a widely accepted non-traditional material removal process used to manufacture components with intricate shapes and profiles. It is considered as a unique adaptation of the conventional EDM process, which uses an electrode to initialize the sparking process. H13 Hot Work Tool Steel has high hot tensile strength, hot wear-resistance and toughness. Good thermal conductivity and insensitiveness to hot cracking, making it suitable not only for hot die applications but also plastic moulds. In this study, it is found that most predominant factors for the maximum material removal rate which is 22.21 mm3/min are current which was found to be 200A and Pulse ON Time 125 µs, however rest four factors (voltage 20V, pulse off time 40µs, wire tension 8N and wire feed 7mm/min) has less impact as compare to the predominant factors. The most predominant factors for Minimum surface roughness which is 0.89µm are wire tension 10N, pulse on time 115µs and servo voltage 60V. However, rest three factors pulse off time 60 µs, peak current 140 A and wire feed 7mm/min has less impact as compare to the predominant factors.


2018 ◽  
Vol 17 (03) ◽  
pp. 277-290
Author(s):  
Lokesh Upadhyay ◽  
M. L. Aggarwal ◽  
Pulak M. Pandey

A lot of research has been done to improve electric discharge machining (EDM) process to overcome the difficulties of lower material removal and surface finish. In the current study, magneto rheological (MR) fluid was used in place of conventional dielectric to develop a new variant of EDM process. A comparative study of MR fluid assisted EDM at the stationary and rotary conditions of the tool with M2 grade high-speed steel as workpiece has been presented. Investigations have been done to evaluate the effect of various process parameters such as percentage volume Al2O3, pulse on time, duty cycle and discharge current on material removal rate and surface roughness with surface morphology. Higher material removal rate and lower surface finish was obtained in rotary magneto rheological fluid assisted EDM as compared to magneto rheological fluid assisted EDM without rotation under the same processing condition at optimum process parameters.


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