Machining of Graphite/Epoxy Composite Materials With Polycrystalline Diamond (PCD) Tools

1991 ◽  
Vol 113 (4) ◽  
pp. 430-436 ◽  
Author(s):  
M. Ramulu ◽  
M. Faridnia ◽  
J. L. Garbini ◽  
J. E. Jorgensen
Keyword(s):  
Flank Wear ◽  
Epoxy Composite ◽  
Wear Behavior ◽  
Polycrystalline Diamond ◽  
Surface Characteristics ◽  
Machining Time ◽  
Machined Surface ◽  
Surface Textures ◽  
Small Cracks ◽  
Pcd Tools

Machining of graphite/epoxy composite material is investigated by turning (cutoff) tests using different grades of polycrystalline diamond (PCD) inserts. The wear behavior of the PCD cutting edge is characterized by small cracks, rounded edges, and flank wear. The flank wear growth rate was found to depend on the microstructure of the tool and machining time. The coarser the PCD grade was, the better the wear resistance. The machined surface characteristics were evaluated by analyzing the surface roughness data and by scanning electron microscopy inspection of machined surface textures. Surface quality was found to get better with the cutting time.

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.

Experimental Investigation on Surface Roughness in Precision Cutting Ti6Al4V Alloy Using Diamond Tools

2014 ◽  
Vol 800-801 ◽  
pp. 576-579
Author(s):  
Lin Hua Hu ◽  
Ming Zhou ◽  
Yu Liang Zhang
Keyword(s):  
Surface Roughness ◽  
Cutting Speed ◽  
Polycrystalline Diamond ◽  
Cutting Parameters ◽  
Limited Range ◽  
Nose Radius ◽  
Machined Surface ◽  
Machined Surface Roughness ◽  
Titanium Alloy Ti6al4v ◽  
Pcd Tools

In this work, cutting experiments were carried out on titanium alloy Ti6Al4V by using polycrystalline diamond (PCD) tools to investigate the effects of the tool geometries and cutting parameters on machined surface roughness. Experimental results show machined surface roughness decreases with increases in the flank angle, tool nose radius and cutting speed within a limited range respectively, and begins to increase as the factors reaches to certain values respectively. And machined surface roughness decreases with increases in feed rate and cutting depth respectively.

Thinning Silicon Wafer with Polycrystalline Diamond Tools

2009 ◽  
Vol 404 ◽  
pp. 157-163
Author(s):  
Pei Lum Tso ◽  
Cheng Huan Chen
Keyword(s):  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
Wafer Surface ◽  
Depth Of Cut ◽  
Entire Surface ◽  
Machined Surface ◽  
Drill Bits ◽  
Ductile Mode ◽  
Critical Depth Of Cut ◽  
Pcd Tools

Sintered polycrystalline diamond (PCD) compacts are normally used for cutting tools, drill bits and wire dies. A novel application of PCD has been developed to use its entire surface carved to create different patterns which are triangle or square shape loaded with leveled millers that can shave brittle materials in ductile mode. Due to numerous cutting edges formed on the same level of PCD tools, which can be used to thin the wafer surface to achieve both flatness and smoothness of the industrial requirements. SEM has been used to observe the surface and subsurface of the thinned wafer surface. The critical depth of cut between ductile and brittle cutting mode is close to 2 µm in this thinning operation. The damaged layers of machined surface have been observed and studied in this paper.

An Analysis of the Wear of Tungsten Carbide and Polycrystalline Diamond Inserts Turning Ti-6Al-4V

2011 ◽  
Author(s):  
David Schrock ◽  
Xin Wang ◽  
Patrick Kwon
Keyword(s):  
Thermal Conductivity ◽  
Grain Size ◽  
Tool Wear ◽  
Flank Wear ◽  
Polycrystalline Diamond ◽  
Laser Scanning Microscopy ◽  
Rake Face ◽  
Crater Wear ◽  
Pcd Tools ◽  
Face Temperature

Dry turning experiments on Ti-6Al-4V were conducted using two grades (finer and coarser) of carbides and polycrystalline diamond (PCD) inserts to study tool wear. Despite of minor compositional difference between two carbide grades, both grades contain 6% Co. Crater wear and flank wear were measured using Confocal Laser Scanning Microscopy (CLSM). Three dimensional rake surface topographies were reconstructed from the CLSM data and wear profiles were extracted. Finite Element Analysis (FEA) was conducted to study the effects of cutting conditions and thermal properties on rake face temperature. Flank wear on the carbide tools indicated that the inserts with the finer grain size exhibited smaller flank wear than the insert of the coarser grain size. This was attributed to reduced abrasive wear in the finer grained inserts as a result of a higher hardness. The carbide grade with a coarser grain size had an enhanced ability to resist crater wear, likely from lower rake face temperatures and the differences in the compositions. It is known that coarser grain carbides have a higher thermal conductivity resulting from increased grain contiguity. FEA was used to study the temperature difference between the two grain-sizes and the effect of thermal conductivity on temperature gradients. Tool wear of the PCD inserts was also studied. The PCD tools showed significant adhesive wear at the 200sfm cutting speed, transitioning to crater wear at 400sfm. With a high thermal conductivity, it is possible that rake face temperatures were low enough to alter the wear mechanism. FEA supports this hypothesis, as the maximum rake face temperature for the PCD inserts were only around 900°C at 200sfm.

Machining Induced Defects and the Influence Factors when Diamond Turning of SiCp/Al Composites

2007 ◽  
Vol 10-12 ◽  
pp. 626-630 ◽  
Author(s):  
Y.F. Ge ◽  
Jiu Hua Xu ◽  
Hui Yang ◽  
S.B. Luo ◽  
Yu Can Fu
Keyword(s):  
Surface Quality ◽  
Volume Fraction ◽  
Single Point ◽  
Influence Factors ◽  
Polycrystalline Diamond ◽  
High Volume ◽  
Diamond Turning ◽  
Dry Cutting ◽  
Machined Surface ◽  
Pcd Tools

Ultra-precision turning tests on SiCp/2024Al and SiCp/ZL101A composites were carried out to investigate the surface quality using single point diamond tools (SPDT) and polycrystalline diamond (PCD) cutters. Examined by SEM, the machined surfaces took on many defects such as pits, voids, microcracks, grooves, protuberances, matrix tearing and so on. The results showed that surface quality debased with increasing feed rate or using of high volume fraction materials. Dry cutting would deteriorate the surface finish. It was also pointed out that SPDT outperformed PCD tools although they produced the same surface roughness Ra. Microhardness measuring showed that the deformation layer was extended to 8–16μm below the machined surface.

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.

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.

Optimization and surface modification in electrical discharge machining of AA 6061/SiCp composite using Cu–W electrode

2015 ◽  
Vol 231 (3) ◽  
pp. 332-348 ◽  
Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar
Keyword(s):  
Process Parameters ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Electrode Wear ◽  
Material Transfer ◽  
Machined Surface ◽  
Recast Layer Thickness ◽  
Pulse On Time ◽  
Pulse Off Time

This paper presents the experimental investigation on the electro-discharge machining of aluminum alloy 6061 reinforced with SiC particles using sintered Cu–W electrode. Experiments have been designed as per central composite rotatable design, using response surface methodology. Machining characteristics such as material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR) have been investigated under the influence of four electrical process parameters; namely peak current, pulse on time, pulse off time, and gap voltage. The process parameters have been optimized to obtain optimal combination of MRR, EWR, and SR. Further, the influence of sintered Cu–W electrode on surface characteristics has been analyzed with scanning electron microscopy, energy dispersive spectroscopy, and Vicker microhardness tests. The results revealed that all the process parameters significantly affect MRR, EWR, and SR. The machined surface properties are modified as a result of material transfer from the electrode. The recast layer thickness is increased at higher setting of electrical parameters. The hardness across the machined surface is also increased by the use of sintered Cu–W electrode.

Alkali-Modified Titanium Surface Stimulating Formation of Bone-Implant Interface

2007 ◽  
Vol 361-363 ◽  
pp. 749-752
Author(s):  
J. Strnad ◽  
Jan Macháček ◽  
Z. Strnad ◽  
C. Povýšil ◽  
Marie Strnadová
Keyword(s):  
Titanium Implant ◽  
Surface Characteristics ◽  
Healing Time ◽  
Machined Surface ◽  
Implant Surface ◽  
Bone Implant ◽  
Bone Response ◽  
Modified Surface ◽  
The Difference ◽  
Titanium Implant Surface

This study was carried out to assess the bone response to alkali-modified titanium implant surface (Bio surface), using histomorphometric investigation on an animal model. The mean net contribution of the Bio surface to the increase in bone implant contact (BIC) with reference to the turned, machined surface was evaluated at 7.94 % (BIC/week), within the first five weeks of healing. The contribution was expressed as the difference in the osseointegration rates ( BIC/'healing time) between the implants with alkali modified surface (Bio surface) and those with turned, machined surface. The surface characteristics that differed between the implant surfaces, i.e. surface morphology, specific surface area, contact angle, hydroxylation/hydration, may represent factors that influence the rate of osseointegration.

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