Electrical Discharge Grinding (EDG) of Polycrystalline Diamond - Effect of Machining Polarity

2014 ◽  
Vol 1025-1026 ◽  
pp. 628-632 ◽  
Author(s):  
Mohammad Zulafif Rahim ◽  
Song Lin Ding ◽  
John Mo
Keyword(s):  
Electrical Discharge ◽  
Complex Geometry ◽  
Polycrystalline Diamond ◽  
Machining Process ◽  
Morphological Examination ◽  
Carbon Structure ◽  
Finishing Process ◽  
Advanced Machining ◽  
The Difference ◽  
Pcd Tools

Electrical discharge grinding (EDG) is an advanced machining process and can be utilised to fabricate complex geometry of PCD tools. However, the PCD removal mechanism in this process is complicated. This study was carried out to understand the difference in PCD surface structure with difference EDG polarities. The study revealed that the finishing process with negative polarity is the reason for the porous structure on the surface. Further analysis on the chemical element and carbon structure were implemented as the morphological examination of the surface.

Residual Stress Analysis of Polycrystalline Diamond after Electrical Discharge Machining

2013 ◽  
Vol 820 ◽  
pp. 106-109 ◽  
Author(s):  
M. Zulafif Rahim ◽  
Arash Pourmoslemi ◽  
Song Lin Ding ◽  
John Mo
Keyword(s):  
Residual Stress ◽  
Electrical Discharge ◽  
Cutting Tool ◽  
Electrical Discharge Machining ◽  
Polycrystalline Diamond ◽  
High Hardness ◽  
Machining Process ◽  
Hard Materials ◽  
Advanced Machining ◽  
Pcd Tools

The extreme hardness of Polycrystalline Diamond (PCD) makes it an ideal choice for the machining of hard materials as a cutting tool. Due to the high hardness, fabrication of PCD tools relies on conventional abrasive grinding which suffers from low machining efficiency. Electrical discharge machining (EDM) is an advanced machining process and can be utilised to fabricate complicated PCD tools. High temperature of sintering and EDM processes creates residual stress inside PCD and can result in unmatured failure of PCD tools. This paper analyses the distribution of residual stress in PCD after electrical discharge machining process.

scholarly journals The Performance of Polycrystalline Diamond (PCD) Tools Machined by Abrasive Grinding and Electrical Discharge Grinding (EDG) in High-Speed Turning

2021 ◽  
Vol 5 (2) ◽  
pp. 34
Author(s):  
Guangxian Li ◽  
Ge Wu ◽  
Wencheng Pan ◽  
Rizwan Abdul Rahman Rashid ◽  
Suresh Palanisamy ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
High Speed ◽  
Flank Wear ◽  
Polycrystalline Diamond ◽  
Machining Efficiency ◽  
Crater Wear ◽  
Wear Process ◽  
High Speed Turning ◽  
Tools Wear ◽  
Pcd Tools

Polycrystalline diamond (PCD) tools are widely used in industry due to their outstanding physical properties. However, the ultra-high hardness of PCD significantly limits the machining efficiency of conventional abrasive grinding processes, which are utilized to manufacture PCD tools. In contrast, electrical discharge grinding (EDG) has significantly higher machining efficiency because of its unique material removal mechanism. In this study, the quality and performance of PCD tools machined by abrasive grinding and EDG were investigated. The performance of cutting tools consisted of different PCD materials was tested by high-speed turning of titanium alloy Ti6Al4V. Flank wear and crater wear were investigated by analyzing the worn profile, micro morphology, chemical decomposition, and cutting forces. The results showed that an adhesive-abrasive process dominated the processes of flank wear and crater wear. Tool material loss in the wear process was caused by the development of thermal cracks. The development of PCD tools’ wear made of small-sized diamond grains was a steady adhesion-abrasion process without any catastrophic damage. In contrast, a large-scale fracture happened in the wear process of PCD tools made of large-sized diamond grains. Adhesive wear was more severe on the PCD tools machined by EDG.

Study on a Magnetic Deburring Method by the Application of the Plane Magnetic Abrasive Machining Process

2009 ◽  
Vol 76-78 ◽  
pp. 276-281 ◽  
Author(s):  
Yan Hua Zou ◽  
Takeo Shinmura ◽  
F. Wang
Keyword(s):  
Magnetic Particles ◽  
Constant Pressure ◽  
Machining Process ◽  
Magnetic Pole ◽  
Shape Accuracy ◽  
Magnetic Abrasive Finishing ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
The Difference ◽  
Pole Surface

This research studies the influence　of constant pressure acting on the magnetic particles brush for the precision machining of planar and curved workpieces. In particular, it examined the effects of constant pressure on improving the formal accuracy of the workpiece. This process method, constant pressure is applied to the magnetic pole of a conventional magnetic brush, the constant pressure acted to the surface of the workpiece through the magnetic particle brush formed at the magnetic pole surface. The authors conducted a plane magnetic abrasive finishing experiment using both the conventional magnetic abrasive finishing process and the newly proposed constant-pressure magnetic abrasive finishing process to compare the deburring characteristics between the processes for removing burrs from holes drilled in brass plate workpieces. In this experiment, a brass disk with a drilled hole was used as a workpiece. As a result, the difference in finishing characteristics was clarified. The results showed that the burr can be removed by use of this new plane magnetic abrasive finishing process and it is more useful than the conventional magnetic brush for improving the shape accuracy of the workpiece.

Electrical Discharge Grinding of Polycrystalline Diamond—Effect of Machining Parameters and Finishing In-Feed

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
M. Zulafif Rahim ◽  
Songlin Ding ◽  
John Mo
Keyword(s):  
Surface Quality ◽  
Electrical Discharge ◽  
Polycrystalline Diamond ◽  
Lower Surface ◽  
Machining Parameters ◽  
Graphite Phase ◽  
Morphological Findings ◽  
Erosion Mechanisms ◽  
Experimental Findings ◽  
Pcd Tools

Electrical discharge grinding (EDG) is becoming more prevalent in the manufacturing of polycrystalline diamond (PCD) tools. This paper concerns investigation of the effects of machining parameters, as well as finishing in-feed, to the surface quality obtained when using EDG to erode PCD. With the aid of the morphological findings, different PCD erosion mechanisms are discussed. Experimental results demonstrated that the eroded surface quality of PCD was significantly affected by the selected parameters. High temperature due to the erosion process resulted in the partial conversion of diamond to graphite phase under the surface. Higher finishing in-feed produced better surface quality and caused lower surface graphitization and lower tensile residual stress. A model for the thermal stress prediction was developed and found to have good agreement with the experimental findings.

ELECTRICAL DISCHARGE GRINDING VERSUS ABRASIVE GRINDING IN POLYCRYSTALLINE DIAMOND MACHINING

2015 ◽  
Vol 74 (10) ◽  
Author(s):  
M. Zulafif Rahim ◽  
Guangxian Li ◽  
Songlin Ding ◽  
John Mo
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Electrical Discharge ◽  
Polycrystalline Diamond ◽  
Quality Indices ◽  
Diamond Machining ◽  
Quality Issue ◽  
Stress Directions ◽  
Conventional Grinding ◽  
Pcd Tools

Electrical Discharge Grinding (EDG) and conventional grinding are two different processes with different removal mechanisms and are typically used to machine Polycrystalline Diamond (PCD). This paper addresses the quality issue of PCD tools produced by these two processes in machining sharp cutting edges. Closely similar visible quality indices (surface roughness and tool sharpness) have been obtained by both processes. However, it was found that there is a difference in residual stress directions and graphitization levels. Through the Raman method, the quantitative analysis of residual stress and graphitization inherence by both processes were also presented and discussed in detail. 

scholarly journals Study of cutting force and tool wear during turning of aluminium with WC, PCD and HFCVD coated MCD tools

2020 ◽  
Vol 7 ◽  
pp. 27
Author(s):  
Sisira Kanta Pattnaik ◽  
Minaketan Behera ◽  
Sachidananda Padhi ◽  
Pusparaj Dash ◽  
Saroj Kumar Sarangi
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Cutting Force ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Machining Process ◽  
Pcd Tool ◽  
Rolled Aluminum ◽  
Pcd Tools

Enormous developmental work has been made in synthesis of metastable diamond by hot filament chemical vapor deposition (HFCVD) method. In this paper, micro-crystalline diamond (MCD) was deposited on WC–6 wt.% Co cutting tool inserts by HFCVD technique. The MCD coated tool was characterized by the scanning electron microscope (SEM), X-ray diffraction (XRD) and micro Raman spectroscopy (μ-RS). A comparison was made among the MCD tool, uncoated tungsten carbide (WC) tool and polycrystalline diamond (PCD) tool during the dry turning of rolled aluminum. The various major tests were conducted such as surface roughness, cutting force and tool wear, which were taken into consideration to establish a proper comparison among the advanced cutting tools. Surface roughness was measured during machining by Talysurf. The tool wear was studied by SEM after machining. The cutting forces were measured by Kistler 3D-dynamometer during the machining process. The test results indicate that, the CVD coated MCD tool and PCD tool produced almost similar results. But, the price of PCD tools are five times costlier than MCD tools. So, MCD tool would be a better alternative for machining of aluminium.

Study on the Wear Mechanism of PCD Tools in High-Speed Milling of Al-Si Alloy

2011 ◽  
Vol 381 ◽  
pp. 16-19 ◽  
Author(s):  
Yong Guo Wang ◽  
Biao Liu ◽  
Jiong Yi Song ◽  
Xiang Ping Yan ◽  
Kang Mei Wu
Keyword(s):  
Wear Mechanism ◽  
High Speed ◽  
Energy Dispersive Spectrometer ◽  
Cutting Speed ◽  
Polycrystalline Diamond ◽  
Machining Process ◽  
Diffusion Wear ◽  
Milling Tool ◽  
Pcd Tools ◽  
And Diffusion

Polycrystalline diamond (PCD) tools have been obtained increasing application in aluminum alloy processing industry due to the excellent surface finish and tool life comparing with other traditional tools. Investigation of the wear mechanism of PCD milling tool for machining Al-Si alloy at cutting speed of 5000m/min (n=12732r/min) has been performed. The wear morphology of tool has been studied by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Results show that PCD milling tool suffers from abrasive wear and diffusion wear on the flank face and adhesive wear on the rake face in the machining process.

scholarly journals Application of Polishing AISI 316L Stainless Steel Ball Bearing with A Magnetic Abrasive Finishing Process: A Review

ROTASI ◽  
2019 ◽  
Vol 20 (4) ◽  
pp. 249 ◽  
Author(s):  
Patrick Munyensanga ◽  
P. Paryanto ◽  
Moh Nor Ali Aziz
Keyword(s):  
Stainless Steel ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Process ◽  
Surface Finishing ◽  
Aisi 316L ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Stainless Steel Ball ◽  
Advanced Machining

Advanced machining process telah terbukti dalam teknologi proses rekayasa untuk surface finishing dan proses material removal, atau dengan proses traditional finishing: fase fundamental, unrestrained, dan permintaan tinggi dalam fase tenaga kerja selama produksi. Finishing abrasif magnetik, pada polishing dalam proses non-konvensional mampu menyelesaikan dengan presisi dengan proses pemesinan yang dikontrol oleh medan magnet dan itu tidak berlaku untuk beberapa proses kompleks di mana teknik penyelesaian konvensional dapat dengan mudah diterapkan. Makalah ini mengulas teknik praktis untuk memoles bantalan AISI 316L ST Ball dengan proses finishing abrasif magnetik untuk menyelesaikan desain permukaan bola eksternal. Parameter input yang berbeda dari proses ditinjau seperti kecepatan elektromagnetik, arus dan tegangan langsung yang diinduksi, kepadatan fluks magnetik, jumlah ukuran partikel abrasif, lingkungan kerja, dan bahan benda kerja. Input yang terjadi untuk proses finishing bantalan bola stainless steel dapat memvalidasi kinerja laju material removal rate dan surface roughness.

COMPARATIVE EVALUATION OF MULTIPARAMETRIC ENDORECTAL ULTRASOUND AND ENHANCED IMAGING COLONOSCOPY IN THE DIAGNOSIS OF EARLY COLORECTAL CANCER

2020 ◽  
Vol 19 (3) ◽  
pp. 49-64
Author(s):  
E. M. Bogdanova ◽  
Yu. L. Trubacheva ◽  
O. M. Yugai ◽  
S. V. Chernyshov ◽  
E. G. Rybakov ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Statistical Significance ◽  
Muscle Layer ◽  
Endorectal Ultrasound ◽  
Diagnostic Methods ◽  
Early Colorectal Cancer ◽  
Morphological Examination ◽  
Optical Magnification ◽  
The Difference ◽  
Enhanced Imaging

AIM: to compare multiparametric endorectal ultrasound (ERUS) and enhanced imaging colonoscopy in the diagnosis of early colorectal cancer.PATIENTS AND METHODS: the study included 78 patients with epithelial rectal tumor. All the patients underwent multiparametric ERUS and colonoscopy with examination by narrow beam imaging (NBI) at optical magnification. All the patients were operated.RESULTS: a morphological examination removed specimens revealed adenomas in 48 cases, in 19 specimens – adenocarcinomas in situ and T1, and in 11 specimens – adenocarcinomas with invasion of the muscle layer or deeper. When calculating the accuracy indicators of diagnostic methods for groups of patients with adenoma, Tis-T1 adenocarcinoma, and T2-T3 adenocarcinoma, the difference in the sensitivity and specificity of the methods in none of the presented groups did not reach the level of statistical significance (p>0.05).ROC analysis showed that ultrasound has a prognostic value comparable to colonoscopy. The area difference was 0.013 (p=0.85).CONCLUSION: endoscopy and ultrasound have similar value in the diagnosis of malignant transformation of rectal adenomas.

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