Fabrication of PCD Micro Tools Using Block EDM Method and Their Application to Different Microstructures in Brittle and Hard Materials

2010 ◽  
Author(s):  
Asma Perveen ◽  
Y. S. Wong ◽  
M. Rahman
Keyword(s):  
Material Removal ◽  
Polycrystalline Diamond ◽  
High Demand ◽  
Hard Materials ◽  
Electro Discharge Machining ◽  
Machining Strategy ◽  
Reduced Dimension ◽  
Different Shapes ◽  
Conical Tool ◽  
Micro Tools

Fabrication of microelectrodes with different shape has become so important due to the high demand of industrial products not only with diversified shape but also of reduced dimension. However, to date, fabrication of different shapes in single setup is not possible and also need special indexing attachment. To solve this problem, in this study, a specially designed block containing three V slot of 60° 90° 120° has been designed and fabricated using wire cut machine to facilitate the fabrication of different shape micro-electrode. Then, with the help of block electro discharge machining method using this specially designed block, the feasibility of fabrication of microelectrodes with symmetrical and non-symmetrical section e.g. conical tool of angle 60° 90° 120°, rectangular, triangular, circular and semicircular tool from commercially available polycrystalline diamond rod has been investigated. As the size of electrode is of micron scale, multi-pass machining strategy has been taken to reduce the volumetric material removal, and thus to diminish the possible electrode breakage, which is especially significant. Finally, this strategy of using specially designed block has been found to be feasible for producing microelectrodes of various symmetrical and non-symmetrical sections down to few microns. In addition to this, the capabilities of these fabricated tools have been depicted by recommending few applications on both conductive and nonconductive material.

EDM with USM Combination Process of Sintered NdFeB Permanent Magnet

2010 ◽  
Vol 44-47 ◽  
pp. 1066-1069
Author(s):  
Li Li ◽  
Li Ling Qi ◽  
Zong Wei Niu
Keyword(s):  
Permanent Magnet ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Dielectric Fluid ◽  
Machined Surface ◽  
Combination Process ◽  
Electro Discharge Machining ◽  
Ndfeb Permanent Magnet ◽  
Machining Characteristics

This paper presents an experimental investigation of the machining characteristics of sintered NdFeB permanent magnet using a combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). Concentration of abrasive in the dielectric fluid is changed to explore its effect on the material removal rate (MRR). MRR of EDM /USM, conventional EDM are compared, machined surface characteristics are also compared between them. It is concluded that the combination EDM/USM process can increase the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate abrasive concentration can improve its machining efficiency.

scholarly journals Electric Discharge Grinding of Polycrystalline Diamond Materials

2012 ◽  
Vol 271-272 ◽  
pp. 333-337 ◽  
Author(s):  
Song Lin Ding ◽  
John P.T. Mo ◽  
Milan Brandt ◽  
Richard Webb
Keyword(s):  
Electrical Discharge ◽  
Material Removal ◽  
Working Condition ◽  
Removal Rate ◽  
Polycrystalline Diamond ◽  
Optimal Parameters ◽  
Power Generator ◽  
The Poor ◽  
Edm Process ◽  
Selection Of

The poor electric conductivity of polycrystalline diamond (PCD) makes it difficult to machine with the conventional EDM process. Inappropriate selection of parameters of the power generator and the servo system leads to unstable working condition and low material removal rate. This paper introduces a method to find optimal parameters in the Electrical Discharge Grinding (EDG) of PCD materials with Taguchi method. The theory and detailed procedures are presented, experimental results are analyzed. The optimized configuration was validated through confirmation tests.

Investigation on the Machining of Thick Diamond Films by EDM Together with Mechanical Polishing

2007 ◽  
Vol 24-25 ◽  
pp. 377-382
Author(s):  
Rong Fa Chen ◽  
Dun Wen Zuo ◽  
Yu Li Sun ◽  
Wen Zhuang Lu ◽  
D.S. Li ◽  
...  
Keyword(s):  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Mechanical Polishing ◽  
Polishing Process ◽  
Two Stage ◽  
Efficient Manner ◽  
Raman Scattering Spectroscopy ◽  
Electro Discharge Machining ◽  
Diamond Polishing ◽  
Cost Efficient

Although research on various diamond polishing techniques has been carried for years, some issues still need to be examined in order to facilitate application on large areas in a cost-efficient manner. A compositive technique for machining efficiently thick diamond films prepared by DC plasma arc jet is reported in the present paper. A two-stage polishing was applied on thick polycrystalline diamond films, by employing first electro-discharge machining (EDM) for rough polishing and subsequently mechanical polishing for finishing operations. Experimental results obtained clearly indicate the applicability of the proposed two-stage technique for fabricating transparent diamond films that can be used for the production of X-ray windows. Appropriate etching with EDM is an effective pretreatment method for enhancing the efficiency of rough polishing process in mechanical polishing of thick diamond film. The machined surfaces of diamond films are studied by Scanning Electron Microscope (SEM) and Raman Scattering Spectroscopy (Raman).

A Discussion on Removal Mechanisms in Grinding Polycrystalline Diamond

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Florestan Schindler ◽  
Richard Brocker ◽  
Fritz Klocke ◽  
Patrick Mattfeld
Keyword(s):  
Material Removal ◽  
Polycrystalline Diamond ◽  
Material Removal Mechanism ◽  
Mesoscopic Scale ◽  
Tool Manufacture ◽  
Brittle Behavior ◽  
Process Characteristics ◽  
Chemical Effects ◽  
Removal Mechanisms ◽  
First Time

Polycrystalline diamond (PCD) grinding takes an important role in the field of tool manufacture. Regardless, there is still lack of process knowledge about the occurring material removal mechanisms in PCD grinding. In order to get a better understanding of the process characteristics, the surface integrity zone of PCD inserts has been analyzed in detail after grinding for the first time. The drawn conclusion questions solely ductile or brittle behavior as removal mechanisms. Both thermal and mechanical process loads during the grinding process lead to thermophysical and chemical effects on a micro- and mesoscopic-scale and might thus have a significant impact on the material removal mechanism.

Experimental studies on graphite powder-mixed electro-discharge machining of Inconel 718 super alloys: Comparison with conventional electro-discharge machining

2018 ◽  
Vol 233 (2) ◽  
pp. 384-402 ◽  
Author(s):  
Santosh Kumar Sahu ◽  
Saurav Datta
Keyword(s):  
Thermal Conductivity ◽  
Residual Stress ◽  
Wear Rate ◽  
Tool Wear ◽  
Inconel 718 ◽  
Material Removal ◽  
Graphite Powder ◽  
Tool Wear Rate ◽  
Machined Surface ◽  
Electro Discharge Machining

Inconel 718 is a nickel-based super alloy widely applied in aerospace, automotive, and defense industries. Low thermal conductivity, extreme high temperature strength, strong work-hardening tendency make the alloy difficult-to-cut. In contrast to traditional machining, nonconventional route like electro-discharge machining is relatively more advantageous to machine this alloy. However, low thermal conductivity of Inconel 718 restricts electro-discharge machining from performing well. In order to improve the electro-discharge machining performance of Inconel 718, powder-mixed electro-discharge machining was reported in this paper. It was carried out by adding graphite powder to the dielectric media in consideration with varied peak discharge current. The morphology and topographical features of the machined surface including surface roughness, crack density, white layer thickness, metallurgical aspects (phase transformation, crystallite size, microstrain, and dislocation density), material migration, residual stress, microindentation hardness, etc. were studied and compared with that of the conventional electro-discharge machining. Additionally, effects of peak discharge current were discussed on influencing different performance measures of powder-mixed electro-discharge machining. Material removal efficiency and tool wear rate were also examined. Use of graphite powder-mixed electro-discharge machining was found to be better in performance for improved material removal rate, superior surface finish, reduced tool wear rate, and reduced intensity as well as severity of surface cracking. Lesser extent of carbon migration onto the machined surface as observed in powder-mixed electro-discharge machining in turn reduced the formation of hard carbide layers. As compared to the conventional electro-discharge machining, graphite powder-mixed electro-discharge machining exhibited relatively less microhardness and residual stress at the machined surface.

scholarly journals Improvement of Machining Processes: A Case Study

2019 ◽  
Vol 2 (3) ◽  
pp. 634-641
Author(s):  
Hakan Gökçe ◽  
Ramazan Yeşilay ◽  
Necati Uçak ◽  
Ali Teke ◽  
Adem Çiçek
Keyword(s):  
Material Removal ◽  
Current Practice ◽  
Complex Geometry ◽  
Vital Role ◽  
Machining Process ◽  
Machining Processes ◽  
Machining Time ◽  
Machining Strategy ◽  
Removal Processes

In material removal processes, determination of optimal machining strategy is a key factor to increase productivity. This situation is gaining more importance when machining components with complex geometry. The current practice in the determination of machining strategy mostly depends on the experience of the machine operator. However, poorly designed machining processes lead to time-consuming and costly solutions. Therefore, the improvement of machining processes plays a vital role in terms of machining costs. In this study, the machining process of a boom-body connector (GGG40) of a backhoe loader was improved. Improvements of toolpaths and cutting conditions of 22 different material removal processes were checked through a CAM software. According to the simulation results, the process plan was rearranged. Besides, some enhancements in casting model were conducted to decrease in the number of machining operations. When compared to current practice, a reduction of 55% in machining time was achieved.

On Correlation of Pulses and Tool Elongations at Micro-Electrical Discharge Machining Aided by Ultrasonics

2015 ◽  
Vol 809-810 ◽  
pp. 309-314
Author(s):  
Daniel Ghiculescu ◽  
Nicolae Marinescu ◽  
Tomasz Klepka ◽  
Nicoleta Carutasu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Micro Electrical Discharge Machining ◽  
Machining Strategy ◽  
Element Method

The paper deals with Finite Element Method (FEM) of thermal and mechanical-hydraulic components of material removal mechanism at micro-electrical discharge machining aided by ultrasonics (μEDM+US), due to EDM and US contribution. The dimensions of craters produced by single discharges under μEDM+US conditions are determined with different pulse durations in order to establish a machining strategy with correlation of pulses and tool elongations.

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