Papers by Keyword: Peak Current

Abstract: This paper present an investigation on cutting speed of ultrasonic vibration assisted wire electrical discharge machining (US-WEDM) for High carbon high chromium D3 Steel. An extensive research study was carried out with an aim to select the optimum cutting condition with the varying amplitude of vibration in order to get the optimum cutting speed for the proposed set-up. The process was mathematically modeled using the response parameters, i.e. cutting speed under a range of control parameters and the main influencing factors were determined for cutting speed criteria Taguchi’s experimentation methodology indicated the contribution of amplitude of vibration (P=6.16%), pulse on time (P=14.54%), pulse off time (P=73.16%) and peak current (P=5.94%). Finally, the optimum parametric setting for different cutting speed arising out of study has synthesized as amplitude of vibration at level 3 (18μm), peak current level 1 (100 units), pulse on time level 2 (118 μ sec) and pulse off time level 2 (46 μ sec) and analyses in this study.

Abstract: WEDM process is newly emerged machining method in past decade which uses spark erosion method for the material removal while machining using high current. This method has shown high dimensional accuracy but gave rise to low machining rate. In current age of ultramodern technology a machine should satisfy more than one purpose. Therefore better Surface finish with dimensional accuracy for WEDM process has been very well presented in this paper with both the responses taken for study simultaneously. The paper deals with WEDM Process variables pulse ON/OFF time, peak current, servo voltage and wire feed rate. The paper also details about reduction of iterations for the desired output by using TLBO (Teaching-Learning Based Optimization) technique. The convergence graphs have been plotted in Minitab software to justify the reduction in iterations.

Abstract: Surface strengthening for H13 steel with powder mixed near dry EDM, research the effect of different discharge parameters on the microstructure and hardness of strengthened layer .The results show that the effect of pulse interval on microstructure and micro hardness is not obvious, the influence of the pulse width less than the peak current. As the increasing of peak current, strengthening layer surface quality get better, when the peak current reach to 14A , preferable microstructure of strengthening layer can be obtained.

Abstract: Electrical discharge machining (EDM) is a non-conventional machining process where materials are removed by the thermal energy exerted from series of electrical sparks. This process is applied for machining of non-conductive alumina (Al₂O₃). The workpiece is covered with the adhesive copper foil to initiate the initial spark between the workpiece and the tool electrode. A pyrolytic carbon (PyC) layer is generated on workpiece surface by dissociating kerosene dielectric after the machining of initial copper assisting electrode (AE) layer. In this study, experiments were performed by varying the peak current and keeping other parameters constant in order to investigate the effect of peak current on material removal rate (MRR) in EDM of Al₂O₃. The results showed that the lowest and the highest values of peak current were 1.1 A and 1.3 A, respectively. Material cannot be removed due to insufficient PyC layer generation for any values of peak current less than 1.1 A or more than 1.3 A. From the results, it is also observed that the MRR is increased when higher peak current values are used. MRR was found to be 0.052 mm³/min at peak current 1.1 A and it was found to be 0.132 mm³/min at peak current 1.3 A.

Abstract: The paper studies micropore electric spark machining of Hymu 80 soft magnetic alloy materials focusing on the influence of gap voltage on the processing to commence the experiment and analyze experimental results. It also discusses the influence of gap voltage on electrode consumption length, the diameter difference of inlet and outlet and reaming amount, find the optimization matching between peak point current and gap voltage, and proposes the idea of improving micropore process.

Abstract: This paper is based on the experimental observation. The micro-topography characteristics of electrical discharge machining (EDM) surface were studied. The results show that the EDM surface is made up of three-dimensional craters and hard protrusions overlapped alternately which distribute randomly and non-directionally. The pulse energy has significant effect on the forming of EDM surface profiles, and peak current and pulse width are the main factors.

Abstract: This paper presents the influence of EDM parameters in terms of peak ampere, pulse on time and pulse off time on surface roughness of titanium alloy (Ti-6Al-4V). A mathematical model for surface finish is developed using response surface method (RSM) and optimum machining setting in favor of surface finish are evaluated. Design of experiments (DOE) techniques is implemented. Analysis of variance (ANOVA) has been performed to verify the fit and adequacy of the developed mathematical models. The acquired results yield that the increasing pulse on time causes fine surface till a certain value and then deteriorates the surface finish. It is investigated that about 200 µs pulse off time produce superior surface finish. These results lead to desirable surface roughness and economical industrial machining by optimizing the input parameters.

Abstract: Dry Electrical discharge machining (Dry EDM), using gas as dielectric, has been developed to solve problems against environment. It has both advantages of high material removal ratio (MRR) and low relative electrode wear ratio (REWR). We investigated the effect of duty factor, peak current, and reference ratio of gap voltage on MRR and REWR of Dry EDM, respectively. Moreover, trying to prove the attachment on electrode surface could decline REWR. It is considered that melting material of work-piece was sputtered and stuck onto electrode surface, and to become a protection layer as result in low REWR. However, the attachment will be removed under the condition of high peak current and high discharge frequency. But the amount of attachment just has little change when discharge number and arc discharge ratio are both decrease.