scholarly journals An Investigation into Accumulative Difference Mechanism in Time and Space for Material Removal in Micro-EDM Milling

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 711
Author(s):  
Qi Jing ◽  
Yongbin Zhang ◽  
Lingbao Kong ◽  
Min Xu ◽  
Fang Ji
Keyword(s):  
Cross Section ◽  
Process Parameters ◽  
Material Removal ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Micro Edm ◽  
Cylindrical Electrode ◽  
Time And Space ◽  
Simulation Results ◽  
The Cross

In micro-electrical discharge machining (micro-EDM) milling, the cross-section of the microgroove machine is frequently not an ideal rectangle. For instance, there are arc shapes on the bottom and corners, and the sidewall is not steep. The theoretical explanation for this phenomenon is still lacking. In addition to the tip discharge effect, the essential reason is that there is an accumulative difference in time and space during the shape change process of a tool electrode and the microstructure formation on a workpiece. The process parameters are critical influencing factors that determine this accumulative difference. Therefore, the accumulative difference mechanism in time and space is investigated in this paper, and then a theoretical model is developed to simulate the micro-EDM milling process with a straight-line single path. The simulation results for a cylindrical electrode at the two rotational speeds of 0 (nonrotating) and 300 rpm are compared, while the results for a cylindrical electrode and a square electrode at a rotation speed of 0 are also compared to verify that different process parameters generate accumulative differences in the time and space of material removal. Finally, micro-EDM milling experiments are carried out to verify the simulation model. The maximum mean relative deviation between the microgroove profiles of simulation results and those of experiments is 11.09%, and the profile shapes of simulations and experiments have a good consistency. A comparative experiment between a cylindrical electrode and a hollow electrode is also performed, which further verifies the mechanism revealed in the study. Furthermore, the cross-section profile of a microgroove can be effectively controlled by adjusting the process parameters when utilising these accumulative differences through fabricating a microgroove with a V-shaped cross-section by a square electrode and a microgroove with a semi-circular cross-section by a cylindrical electrode. This research provides theoretical guidance for solving the problems of the machining accuracy of detail features in micro-EDM milling, for instance, to machine a microgroove with an ideal rectangular cross-section.

Springback law of high-strength 21-6-9 stainless steel tube in numerical control bending under different process parameters

2015 ◽  
Vol 231 (10) ◽  
pp. 1783-1792 ◽  
Author(s):  
Jun Fang ◽  
Shiqiang Lu ◽  
Kelu Wang ◽  
Zhengjun Yao
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Cross Section ◽  
Process Parameters ◽  
High Strength ◽  
Steel Tube ◽  
Numerical Control ◽  
Stainless Steel Tube ◽  
Outer Diameter ◽  
The Cross

In order to achieve the precision bending deformation, the effects of process parameters on springback behaviors should be clarified preliminarily. Taking the 21-6-9 high-strength stainless steel tube of 15.88 mm × 0.84 mm (outer diameter × wall thickness) as the objective, the multi-parameter sensitivity analysis and three-dimensional finite element numerical simulation are conducted to address the effects of process parameters on the springback behaviors in 21-6-9 high-strength stainless steel tube numerical control bending. The results show that (1) springback increases with the increasing of the clearance between tube and mandrel Cm, the friction coefficient between tube and mandrel fm, the friction coefficient between tube and bending die fb, or with the decreasing of the mandrel extension length e, while the springback first increases and then remains unchanged with the increasing of the clearance between tube and bending die Cb. (2) The sensitivity of springback radius to process parameters is larger than that of springback angle. And the sensitivity of springback to process parameters from high to low are e, Cb, Cm, fb and fm. (3) The variation rules of the cross section deformation after springback with different Cm, Cb, fm, fb and e are similar to that before springback. But under same process parameters, the relative difference of the most measurement section is more than 20% and some even more than 70% before and after springback, and a platform deforming characteristics of the cross section deformation is shown after springback.

Simulation Investigation of Tangential-Feed Centerless Grinding Process Performed on Surface Grinder

2009 ◽  
Vol 626-627 ◽  
pp. 23-28
Author(s):  
Wei Xing Xu ◽  
Yong Bo Wu ◽  
Takashi Sato ◽  
Wei Min Lin
Keyword(s):  
Elastic Deformation ◽  
Process Parameters ◽  
Simulation Method ◽  
Machining Accuracy ◽  
Grinding Process ◽  
Elasticity Parameter ◽  
Grinding Method ◽  
Centerless Grinding ◽  
Simulation Results ◽  
Grinding Technique

In our previous study, a new centerless grinding method using surface grinder was proposed. This paper describes a simulation method for investigating the workpiece rounding process in which a model taking the elastic deformation of the machine into consideration is created, and revealing how the process parameters affect the machining accuracy in the new grinding technique. In addition, a practice way to determine the machining-elasticity parameter showing the elastic deformation is developed. The simulation results are compared to show the effect of process parameters on the machining accuracy.

Investigating the Effect of Machining Parameters on Microdrilling of Titanium Grade 19 Alloy

2013 ◽  
Author(s):  
Shivraj Yeole ◽  
Nagabhushana Ramesh Nunna ◽  
Balu Naik Banoth
Keyword(s):  
Process Parameters ◽  
Material Removal ◽  
Removal Rate ◽  
Electrode Wear ◽  
Machining Parameters ◽  
Micro Edm ◽  
Electrode Diameter ◽  
Micro Holes ◽  
Titanium Grade ◽  
Edm Process

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.

Analysis of the Cavitation in the Jet Flow Field of the V-Type Valve Orifice

2015 ◽  
Vol 779 ◽  
pp. 55-61
Author(s):  
Hao Ling Ren ◽  
Tian Liang Lin ◽  
Cheng Miao ◽  
Zhong Shen Li ◽  
Sheng Jie Fu
Keyword(s):  
Flow Field ◽  
Cross Section ◽  
Hydraulic Systems ◽  
Cavitation Model ◽  
Valve Orifice ◽  
The Common ◽  
Simulation Results ◽  
The Cross ◽  
Pressure Stress ◽  
Hydraulic Valves

Valve orifice is the common place that the cavitation easily occurs in the hydraulic systems. This paper introduces a criteria to estimate the inception of the cavitation of the V-type valve orifice with the stress state. Based on this criteria, a cavitation model which considers the dynamics of the cavity and incompressible gas is proposed to analyze the pressure, stress and the cavitation distribution of the phase in the V-type orifice. The distributions of the cavitation along the axis and the cross section are analyzed. The simulation results show that the cavitation is easily occurred in the downstream just after the orifice and the bubbles are mostly gathered in the top of the cross section which is vertical to the axis of the flow field. The simulation results is reasonable according to the facts. Accordingly, the cavitation of the V-type orifice is predicted reasonably. The research and results of this paper are useful for the design of the hydraulic valves.

Ground-state and isomeric-state cross-sections for 92Mo(n,α)89Zr and 95Mo(n,p)95Nb reactions in the 13–15 MeV energy region

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Junhua Luo ◽  
Li Jiang
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Nuclear Decay ◽  
Excitation Functions ◽  
Total Cross Sections ◽  
Γ Ray ◽  
Simulation Results ◽  
The Cross ◽  
Isomeric Ratios

Abstract The (n,α) and (n,p) cross-sections and their isomeric ratios (σ m /σ g ) were measured at 13–15 MeV for 92Mo and 95Mo by activation and off-line γ-ray spectrometry. The activated Mo samples combined with Al foils were used to obtain the cross-section values and the neutron flux, generated using the 3H(d,n)4He reaction. The cross-sections of the ground states were obtained using the metastable state absolute cross-sections and the residual nuclear decay rule. The excitation functions, total cross-sections, and isomeric ratios for the 92Mo(n,α)89m,gZr and 95Mo(n,p)95m,gNb reactions were calculated using the TALYS-1.95 software. 92Mo(n,α)89m + gZr and 95Mo(n,p)95m + gNb reaction excitation functions were obtained using the EMPIRE-3.2.3 package. These simulation results were compared with the corresponding experimental data and with the evaluated data from the ENDF/B-VIII.0, JEFF-3.3, CENDL-3, and ROSFOND libraries. Only partial agreements were observed.

scholarly journals Simulasi Numerik Reaksi Fusi Nuklir dengan menggunakan Metode Wong

2016 ◽  
Vol 6 (01) ◽  
pp. 50
Author(s):  
Muhammad Zamrun Firihu ◽  
Viska Inda Variani ◽  
J Justina
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Cross Section ◽  
Fusion Reaction ◽  
Fusion Cross Section ◽  
Chi Square ◽  
Simulation Results ◽  
The Cross

The numerical simulation for calculating the cross section of fusion reaction is done by using Wong formula. We especially calculated the cross section for the fusion reaction of light systems, i.e. 12C+12C, 16O+12C and 16O+16O reactions. We compared the obtained cross section with experimental data. In order to check the accuracy of the calculations, the chi-square analisys is then permormed. We found that the simulation results of the fusion cross section obtained using Wong Formula well explain the experimetal data of the fusion cross section for the 12C+12C, 16O+12C and 16O+16O reactions. This finding indicates that the Wong formula can be used for studing the fusion reaction of light systems.

Optimization of Process Parameters in Micro Electro- Discharge Drilling [micro EDM-Drilling]: A Taguchi Approach

2012 ◽  
Vol 622-623 ◽  
pp. 30-34 ◽  
Author(s):  
C.K. Nirala ◽  
B. Reddy ◽  
P. Saha
Keyword(s):  
Process Parameters ◽  
Removal Rate ◽  
Signal To Noise Ratio ◽  
Parameter Analysis ◽  
Tool Electrode ◽  
Drilling Process ◽  
Machining Parameters ◽  
Micro Edm ◽  
Tungsten Carbide Tool ◽  
Edm Drilling

This paper applies Taguchi methodology to optimize the machining parameters in micro EDM-drilling of copper using a tungsten carbide tool electrode. The experimental design has been applied to find out the optimal combination of process parameters corresponding to maximum material removal rate, minimum over-cut, minimum tool wear ratio and minimum error-in-depth of drilled hole. Orthogonal array and signal-to-noise ratio is employed to optimize the process parameter. Analysis of variance (ANOVA) is performed to determine the influence of parameters such as, gap voltage, capacitance, feed rate and spindle rotationof micro EDM-drilling process on the performance measures. From the analysis, it is concluded that gap-voltage and capacitance arethe most significant parameters whereas spindle speed is the least among all.

Effect of Tool Electrode Material on the Spark Erosion of Micro Grooves

2006 ◽  
Vol 526 ◽  
pp. 79-84
Author(s):  
S.H. Yeo ◽  
M. Murali ◽  
S. Balakrishnan
Keyword(s):  
Material Removal ◽  
Electrode Materials ◽  
Removal Rate ◽  
Experimental Investigations ◽  
Tool Electrode ◽  
Micro Edm ◽  
Rough Machining ◽  
Electro Discharge Machining ◽  
Spark Erosion ◽  
Materials Used

Micro electro discharge machining is an important unconventional metal micromachining technology. The performance of micro EDM depends on the combination of the tool and work materials used. In the absence of a comprehensive theoretical model to predict the effect of electrode materials on the performance of EDM, experimental investigations as described in this paper become useful. The work materials studied include ferrous, non-ferrous and exotic material (XW42, Ti6Al4V, WC) and the tool electrode materials include the commonly used EDM tool materials namely tungsten, copper and graphite. It is found that in the microgroove machining by micro EDM using foil electrodes, graphite consistently provides higher material removal rate than tungsten and copper tool electrodes and hence it is useful for the rough machining. On the other hand tungsten tool electrode is preferable for finish machining as it provides the least surface roughness.

Investigating the Micro-EDM Machinability of Bulk Metallic Glass in Micro-EDM Drilling

2019 ◽  
Author(s):  
Chong Liu ◽  
Asif Rashid ◽  
Muhammad P. Jahan ◽  
Jianfeng Ma
Keyword(s):  
Aspect Ratio ◽  
Wear Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Tool Electrode ◽  
Micro Edm ◽  
Tool Wear Rate ◽  
Micro Holes

Abstract Bulk Metallic Glass (BMG) is a solid metallic material with disordered atomic structure, that has the characteristics of high elasticity, hardness, fracture toughness, and superior corrosion resistance. High aspect ratio micro-through holes on BMG has prospective applications in space, nuclear reactor, thermodynamics engineering, biomedical, and electronics industries. In this study, the micro-EDM machinability of BMG (Vit 1b: Zr67Cu10.6Ni9.8Ti8.8Be3.8 (wt%)) is evaluated. The micro-EDM machinability of BMG has been assessed based on the volume of material removal rate (MRR), tool wear rate (TWR), micro-hole surface quality, and dimensional accuracy. The effect of various electrical and non-electrical parameters is studied. It is found that micro-EDM is capable producing high aspect ratio micro-holes on difficult-to-machine BMG. The deposition of resolidified debris around the edge of the micro-holes, both at the entrance and exit side, are found to be a common phenomenon in micro-EDM of BMG. The reduction of capacitance was found to be the effective way for reducing the resolidified debris around the edges. Capacitance was found to be have more pronounced effect, with gap voltage having little effect on the quality of micro-holes. The electrode rotational speed had insignificant effect on the quality of micro-holes. In terms of dimensional accuracy, which was measured by overcut and taper angle, both the gap voltage and electrode rotational speed had little effect. The lower electrode rpm was found to reduce the taperness of the micro-holes, although the material removal rate decreases and tool wear rate increases. Finally, analysis of the composition of tool electrode before and after machining indicates the migration of materials from the dielectric and workpiece to the tool electrode and vice versa.

Influence of Side-Insulation Film on Hybrid Process of Micro EDM and ECM for 3D Micro Structures

2011 ◽  
Vol 230-232 ◽  
pp. 517-521 ◽  
Author(s):  
Man Hong Hu ◽  
Yong Li ◽  
Xiao Gu Zhu ◽  
Hao Tong
Keyword(s):  
3D Structure ◽  
Side Wall ◽  
Hybrid Process ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Micro Edm ◽  
Film Property ◽  
Workpiece Material ◽  
Machining Speed ◽  
Micro Structures

This paper describes a hybrid process of Micro EDM and ECM to fabricate 3D microstructures. Micro electro discharge servo scanning machining (Micro EDSSM) is used to remove most part of workpiece material with fast machining speed, while Micro electrochemical scanning machining (Micro ECSM) with side-insulated tool electrode is used to remove the residual material and form the final 3D-structure surface. The application of side-insulated electrode during Micro ECSM is a key technological method to improve the machining accuracy of hybrid process. The effect of side-insulation film property to the movement of hydrogen bubble generated during Micro ECSM is discussed. The hydrophobic film can reduce damages to the junction between film edge and tool-electrode through the attraction to hydrogen, and a hydrophilic 704-silica material is firstly introduced for the fabrication of side-insulation film on the micro rod tool electrode by spin-coating technique. The 704-silica insulation film can effectively isolate the side of tool electrode with electrolyte. Micro 3D structures with uniform side-machining gap and small tape side-wall are machined. The surface with no heat-influence layer and 0.52μm Rahas been achieved.

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