Effect of grain boundary on polycrystalline diamond polishing by high-speed dynamic friction

2021 ◽  
pp. 108461
Author(s):  
Yifan Liang ◽  
Yuting Zheng ◽  
Junjun Wei ◽  
Xin Jia ◽  
Xiaohua Zhu ◽  
...  
Keyword(s):  
Grain Boundary ◽  
High Speed ◽  
Polycrystalline Diamond ◽  
Dynamic Friction ◽  
Diamond Polishing

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.

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).

Application and Advance in Super-Hard Tool Material

2011 ◽  
Vol 84-85 ◽  
pp. 228-231
Author(s):  
Jing Su ◽  
Yu Hua Zhang ◽  
Di Wang
Keyword(s):  
High Speed ◽  
High Performance ◽  
Cubic Boron Nitride ◽  
Tool Material ◽  
Polycrystalline Diamond ◽  
High Speed Cutting ◽  
Machining Quality ◽  
Finished Surface ◽  
Materials Used ◽  
Surface Precision

For the excellent properties, super-hard tool material has received much attention from researchers. The development of super-hard tool material for high-speed cutting could brought high machining quality and surface precision. For an engineer, adopt high performance of tool material, for example wearing resistance, high stability of PCD (polycrystalline diamond) and PCBN (poly cubic boron nitride) can get more information for obtaining higher finished surface quality that cannot acquire just by common cutting process. This paper introduces super-hard cutters materials (PCD and PCBN) development, and discusses several material properties. The features of materials used in different cutting fields are given.

Development of Super-Hard Cutter Material

2013 ◽  
Vol 341-342 ◽  
pp. 3-7
Author(s):  
Hui Ying Feng ◽  
Xiao Jing Li
Keyword(s):  
High Speed ◽  
Cubic Boron Nitride ◽  
Tool Material ◽  
Polycrystalline Diamond ◽  
Machining Process ◽  
Main Research ◽  
High Speed Cutting ◽  
Finished Surface ◽  
Materials Used ◽  
Surface Precision

Super-hard tool material is a main research point of mechanical engineering because of excellent performance. The development of technology for high-speed cutting process could enhance the machining quality and surface precision. It is a difficulty thing to get higher finished surface for traditional machining process. However, the super-hard cutter material could enhance the finished performance of tool material. For example, the wearing resistance, high stability of PCD (polycrystalline diamond) and PCBN (poly cubic boron nitride) can get more information for obtaining higher finished surface quality. The author introduces super-hard cutters materials (PCD and PCBN) development, and discusses several material properties. The features of materials used in different cutting fields are discussed.

Sustainable High Speed Dry Cutting of Magnesium Alloys

2012 ◽  
Vol 723 ◽  
pp. 3-13
Author(s):  
Yue Bin Guo ◽  
Zhan Qiang Liu
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Energy Use ◽  
Internal State ◽  
Polycrystalline Diamond ◽  
Mg Alloys ◽  
Plasticity Model ◽  
Machining Performance ◽  
Dry Cutting ◽  
Pcd Tools

Magnesium (Mg) components can significantly reduce energy use due to their low densities compared to the majority alloys. Mg alloys are often machined to fit individual cases. However, process mechanics by high-speed dry cutting of Mg alloys are poorly understood. This study focuses on machining ability of biomedical magnesium-calcium (Mg-Ca) alloys. First, it presents a modeling approach of mechanical behavior of Mg-Ca0.8 (wt %) alloy under cutting regimes using the internal state variable (ISV) plasticity model. Then, the ISV plasticity model is implemented to simulate high speed dry cutting of Mg-Ca0.8 alloy by finite element method. Last, machining performance in the context of sustainability is discussed. Excellent surface finish can be achieved in the range of high cutting speeds. Continuous chip formation predicted by the finite element simulation is verified by high speed dry cutting of Mg-Ca0.8 using polycrystalline diamond (PCD) inserts. Chip ignition as the most hazardous aspect in machining Mg alloys does not occur for in high-speed dry cutting with sharp PCD tools. The predicted temperature distribution well explains the reason for the absence of chip ignition in high speed dry cutting of Mg-Ca0.8 alloy. A mechanism of built-up layer (BUL) formation is proposed.

Surface Integrity of Magnesum-Calcium Orthopedic Biomaterial Procesed by Dry High-Speed Face Milling

2010 ◽  
Author(s):  
M. Salahshoor ◽  
Y. B. Guo
Keyword(s):  
Surface Integrity ◽  
Human Body ◽  
High Speed ◽  
Mechanical Load ◽  
Cutting Speed ◽  
Polycrystalline Diamond ◽  
Orthopedic Implants ◽  
Face Milling ◽  
Depth Of Cut ◽  
Machining Parameter

Biodegradable magnesium-calcium (Mg-Ca) implants have the ability to gradually dissolve and absorb into the human body after implantation. The critical issue that hinders the application of Mg-Ca implants is its poor corrosion resistance to human body fluids. A promising approach to tackle this issue is tailoring the surface integrity characteristics of the orthopedic implants to get an appropriate corrosion kinetic. High speed face milling of biodegradable Mg-Ca alloy is used in this study as a possible way to achieve that goal. Polycrystalline diamond inserts are used to avoid material adhesion and likely fire hazards. All the cutting tests are performed without using coolant to keep the manufacturing process ecological. High cutting speed of 40 m/s and 200 μm depth of cut are applied in a broad range of feed values to cover finish and rough cutting regimes. The effect of feed as a key machining parameter which defines the amount and duration of thermo-mechanical load and ultimately provides higher chances for surface integrity changes are investigated.

Phase Reactions During Sintering of M3/2 Based Composites with WC Additions

2013 ◽  
Vol 58 (3) ◽  
pp. 703-708 ◽  
Author(s):  
M. Madej
Keyword(s):  
Grain Boundary ◽  
Carbide Phase ◽  
High Speed ◽  
Brinell Hardness ◽  
High Speed Steel ◽  
Hardness Test ◽  
Edx Analysis ◽  
Boundary Film ◽  
Dilatometric Studies ◽  
Cold Pressed

Abstract Attempts have been made to describe the influence of WC additions on properties of M3/2 high speed steel (HSS) based composites. The powder compositions used to produce skeletons for further infiltration were M3/2, M3/2+10%WC and M3/2+30%WC. The powders were cold pressed at 800 MPa. The green compacts were subsequently sintered for 60 minutes at 1150°C in vacuum. These as-sintered specimens were used for copper infiltration. A qualitative EDX analysis revealed presence of both MC type vanadium-rich carbides and M6C type tungsten and iron rich carbides. In specimens containing 10 and 30% WC the carbide phase was uniformly distributed within copper-rich regions. The WC monocarbide reacts with the surrounding HSS matrix and forms a carbide grain boundary film. The microstructural observations of the as-sintered specimens was followed by Brinell hardness test and supplemented with dilatometric studies.

Nanocrystalline Diamond as a Dielectric for SOD Applications

2007 ◽  
Vol 1039 ◽  
Author(s):  
Mose Bevilacqua ◽  
Niall Tumilty ◽  
Aysha Chaudhary ◽  
Haitao Ye ◽  
James E Butler ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Microwave Plasma ◽  
Chemical Vapour ◽  
Polycrystalline Diamond ◽  
Growth Conditions ◽  
Nanocrystalline Diamond ◽  
Free Standing ◽  
Single Crystal Diamond

AbstractNanocrystalline diamond (NCD) has been grown on oxide coated silicon wafers by microwave plasma assisted chemical vapour deposition using a novel seeding technique followed by optimised growth conditions, and leads to a highly-dense form of this material with grain sizes around 100nm for films approximately 1.5 microns thick. The electrical properties of these films have been investigated using Impedance Spectroscopy, which enables the contributions from sources characterised by differing capacitances, such as grain boundaries and grain interiors, to be isolated. After an initial acid clean the electrical properties of the film are not stable, and both grain boundaries and grains themselves contribute to the frequency dependant impedance values recorded. However, following mild oxidation grain boundary conduction is completely removed and the films become highly resistive (>1013 ohm/sq). This is most unusual, as conduction through NCD material is more normally dominated by grain boundary effects. Interestingly, the AC properties of these films are also excellent with a dielectric loss value (tan δ) as low as 0.002 for frequencies up to 10MHz. The dielectric properties of these NCD films are therefore as good as high quality free-standing (large grain) polycrystalline diamond films, and not too dissimilar to single crystal diamond, and are therefore ideally suited to future ‘silicon-on-diamond’ applications.

Sign in / Sign up

Export Citation Format

Share Document