Deposition in Microwave Plasma and Performance of Polycrystalline Diamond Coatings with High Adhesion on Sialon Ceramics Cutting Tools

2020 ◽  
Author(s):  
Eugeny Ashkinazi ◽  
Victor Ralchenko ◽  
Vitaliy Konov ◽  
Dmitry Vinogradov ◽  
Artem Martyanov ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
Diamond Coatings ◽  
High Adhesion ◽  
And Performance

scholarly journals Influence of the Heat Dissipation Mode of Long-Flute Cutting Tools on Temperature Distribution during HFCVD Diamond Films

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 394
Author(s):  
Zhang ◽  
Qian ◽  
wang ◽  
Huang ◽  
Zhang ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Focal Point ◽  
Cutting Tools ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Decisive Role ◽  
Diamond Coatings ◽  
The Difference ◽  
The Individual

The distribution of substrate temperature plays a decisive role on the uniformity of polycrystalline diamond films on cemented carbide tools with a long flute, prepared by a hot filament chemical vapor deposition (HFCVD). In this work, the heat dissipation mode at the bottom of tools is a focal point, and the finite volume method (FVM) is conducted to simulate and predict the temperature field of tools, with the various materials of the holder placed under the tools. The simulation results show that the thermal conductivity of the holder affects the temperature difference of the individual tools greatly, but only affects the temperature of different tools at the same XY plane slightly. Moreover, the ceramic holder can reduce the difference in temperature of an individual tool by 54%, compared to a copper one. Afterwards, the experiments of the deposition of diamond films is performed using the preferred ceramic holder. The diamond coatings on the different positions present a highly uniform distribution on their grain size, thickness, and quality.

Large Area Deposition of Polycrystalline Diamond Coatings by Microwave Plasma CVD

2013 ◽  
Vol 72 (4) ◽  
pp. 225-232 ◽  
Author(s):  
Awadesh K. Mallik ◽  
Sandip Bysakh ◽  
Kalyan S. Pal ◽  
Nandadulal Dandapat ◽  
Bichitra K. Guha ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Polycrystalline Diamond ◽  
Diamond Coatings ◽  
Plasma Cvd ◽  
Large Area ◽  
Microwave Plasma Cvd ◽  
Area Deposition

Polycrystalline Diamond Coating on Orthopaedic Implants: Realization, and Role of Surface Topology and Chemistry in Adsorption of Proteins and Cell Proliferation

2022 ◽  
Author(s):  
Justas Zalieckas ◽  
Ivan Rios Mondragon ◽  
Paulius Pobedinskas ◽  
Arne Skodvin Kristoffersen ◽  
Samih Mohamed-Ahmed ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Microwave Plasma ◽  
Polycrystalline Diamond ◽  
Surface Topology ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Type I ◽  
Diamond Coatings ◽  
Orthopaedic Implants

Polycrystalline diamond has the potential to improve the osseointegration of orthopaedic implants compared to conventional osteo-implant materials such as titanium. However, despite the excellent biocompatibility and superior mechanical properties, the major challenge of using diamond for implants such as those used for hip arthroplasty is the limitations of microwave plasma chemical vapor deposition (CVD) techniques to synthesize diamond on complex-shaped objects. Here, for the first time we demonstrate diamond growth on titanium acetabular shells using surface wave plasma CVD method. Polycrystalline diamond coatings were synthesized at low temperatures (~400 °C) on three types of acetabular shells with different surface structure and porosity. We achieved diamond growth on highly porous surfaces designed to mimic the structure of the trabecular bone and improve osseointegration. Biocompatibility was investigated on nanocrystalline diamond (NCD) and ultrananocrystalline diamond (UNCD) coatings terminated either with hydrogen or oxygen. To understand the role of diamond surface topology and chemistry in attachment and proliferation of mammalian cells we investigated adsorption of extracellular matrix (ECM) proteins, and monitored metabolic activity of fibroblasts, osteoblasts, and bone marrow-derived mesenchymal stem cells (MSCs). The interaction of bovine serum albumin (BSA) and Type I collagen with diamond surface was investigated by confocal fluorescence lifetime imaging microscopy (FLIM). We found that proliferation of MSCs was better on hydrogen terminated UNCD than on oxygen terminated counterpart. These findings corelate to the behaviour of collagen on diamond substrates observed by FLIM. Hydrogen terminated UNCD provides better adhesion and proliferation for MSCs, compared to titanium, while growth of fibroblasts is poorest on hydrogen terminated NCD and osteoblasts behave similarly on all tested surfaces. These results open new opportunities for application of diamond coatings on orthopaedic implants.

scholarly journals Characterizations of microwave plasma CVD grown polycrystalline diamond coatings for advanced technological applications

2014 ◽  
Vol 8 (2) ◽  
pp. 69-80 ◽  
Author(s):  
Awadesh Mallik ◽  
Nandadulal Dandapat ◽  
Shirshendu Chakraborty ◽  
Ashok Mandal ◽  
Jiten Ghosh ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Polycrystalline Diamond ◽  
Potential Candidate ◽  
Diamond Coatings ◽  
Etching Technique ◽  
X Ray ◽  
Microwave Plasma Cvd ◽  
Scanning Electronmicroscopy

Polycrystalline diamond (PCD) coatings ranging from few microns to several hundred microns thickness have been grown by 915MHz microwave plasma reactor with 9000W power. The coatings were deposited on 100mm diameter silicon (Si) substrate from few hours to several days of continuous runs. PCD coatings were made freestanding by wet chemical etching technique. The deposited PCDs were evaluated by X-ray diffraction (XRD), scanning electronmicroscopy (SEM), Raman spectroscopy,X-ray photoelectron spectroscopy (XPS) for physical characterization and compared with authors? earlier work. Refractive index of 2.41 was obtained at 633 nm wavelength and a maximum of 6.6 W?cm-1K-1 value for thermal conductivity could be achieved with the grown coatings. The values are well above the existing non-diamond heat spreading substrates, which makes the grown PCDs as candidates for heat spreaders in different technological applications. High refractive in- dex along with translucent nature of the white freestanding PCDs, make them potential candidate for optical windows.

Adhesion Improvement of CVD Diamond Coatings on WC-Co Substrates for Machining Applications

2004 ◽  
Vol 843 ◽  
Author(s):  
Zhenqing Xu ◽  
Ashok Kumar ◽  
Leonid Lev ◽  
Michael Lukitsch ◽  
Arun Sikder
Keyword(s):  
Diamond Film ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Cutting Tools ◽  
Indentation Test ◽  
Chemical Vapor ◽  
Diamond Powder ◽  
Nucleation Density ◽  
Diamond Coatings ◽  
Diamond Powders

ABSTRACTIn order to improve the performance of WC-Co cutting tools, high quality microcrystalline diamond coatings were produced using microwave plasma enhanced chemical vapor deposition (MPECVD) method. The adhesion of the diamond film deposited on the substrate has been considered to play an important role in the performance of the cutting tools in machining applications. A thin layer of Cr was coated on the WC-Co substrate before the diamond deposition; 75 μm diamond powders were sandblasted on the surface at 40 Psi to increase the nucleation density. Diamond film has been successfully deposited on the substrate at temperature around 750°C with 1.5 % CH4 in Hydrogen plasma. Scanning electron microscopy (SEM) has been used to study the surface morphology and Raman spectroscopy has been performed to characterize the quality of the diamond films and measure the residual stress. The adhesion of the diamond film has been evaluated by Rockwell indentation test. The results indicated that film grown on the Cr interlayer with diamond powder sandblasting has much better adhesion strength.

scholarly journals Feasibility of Cobalt-Free Nanostructured WC Cutting Inserts for Machining of a TiC/Fe Composite

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3432
Author(s):  
Edwin Gevorkyan ◽  
Mirosław Rucki ◽  
Tadeusz Sałaciński ◽  
Zbigniew Siemiątkowski ◽  
Volodymyr Nerubatskyi ◽  
...  
Keyword(s):  
Cubic Boron Nitride ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Machined Surface ◽  
Powder Consolidation ◽  
Plasma Sintering ◽  
Cutting Inserts ◽  
Spark Plasma ◽  
And Performance ◽  
Nanostructured Tungsten Carbide

The paper presents results of investigations on the binderless nanostructured tungsten carbide (WC) cutting tools fabrication and performance. The scientific novelty includes the description of some regularities of the powder consolidation under electric current and the subsequent possibility to utilize them for practical use in the fabrication of cutting tools. The sintering process of WC nanopowder was performed with the electroconsolidation method, which is a modification of spark plasma sintering (SPS). Its advantages include low temperatures and short sintering time which allows retaining nanosize grains of ca. 70 nm, close to the original particle size of the starting powder. In respect to the application of the cutting tools, pure WC nanostructure resulted in a smaller cutting edge radius providing a higher quality of TiC/Fe machined surface. In the range of cutting speeds, vc = 15–40 m/min the durability of the inserts was 75% of that achieved by cubic boron nitride ones, and more than two times better than that of WC-Co cutting tools. In additional tests of machining 13CrMo4 material at an elevated cutting speed of vc = 100 m/min, binderless nWC inserts worked almost three times longer than WC-Co composites.

scholarly journals Multilayer Diamond Coatings Applied to Micro-End-Milling of Cemented Carbide

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3333
Author(s):  
Eduardo L. Silva ◽  
Sérgio Pratas ◽  
Miguel A. Neto ◽  
Cristina M. Fernandes ◽  
Daniel Figueiredo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
End Milling ◽  
Interfacial Stress ◽  
Cemented Carbide ◽  
Air Cooling ◽  
Micro Machining ◽  
Diamond Coatings ◽  
Wear Properties ◽  
High Adhesion ◽  
Micro End Milling

Cobalt-cemented carbide micro-end mills were coated with diamond grown by chemical vapor deposition (CVD), with the purpose of micro-machining cemented carbides. The diamond coatings were designed with a multilayer architecture, alternating between sub-microcrystalline and nanocrystalline diamond layers. The structure of the coatings was studied by transmission electron microscopy. High adhesion to the chemically pre-treated WC-7Co tool substrates was observed by Rockwell C indentation, with the diamond coatings withstanding a critical load of 1250 N. The coated tools were tested for micro-end-milling of WC-15Co under air-cooling conditions, being able to cut more than 6500 m over a period of 120 min, after which a flank wear of 47.8 μm was attained. The machining performance and wear behavior of the micro-cutters was studied by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Crystallographic analysis through cross-sectional selected area electron diffraction patterns, along with characterization in dark-field and HRTEM modes, provided a possible correlation between interfacial stress relaxation and wear properties of the coatings. Overall, this work demonstrates that high adhesion of diamond coatings can be achieved by proper combination of chemical attack and coating architecture. By preventing catastrophic delamination, multilayer CVD diamond coatings are central towards the enhancement of the wear properties and mechanical robustness of carbide tools used for micro-machining of ultra-hard materials.

Fibrous structures on diamond and carbon surfaces formed by hydrogen plasma under direct-current bias and field electron-emission properties

2003 ◽  
Vol 18 (2) ◽  
pp. 305-326 ◽  
Author(s):  
Koji Kobashi ◽  
Takeshi Tachibana ◽  
Yoshihiro Yokota ◽  
Nobuyuki Kawakami ◽  
Kazushi Hayashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Field Emission ◽  
Direct Current ◽  
Electron Emission ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Polycrystalline Diamond ◽  
Metal Catalyst ◽  
Direct Current Bias ◽  
Conical Structures

Polycrystalline diamond films, single crystal bulk diamonds, and diamond powder were treated in microwave plasma of hydrogen at 1.6 torr under a negative direct-current bias of −150 to −300 V without metal catalyst. It was found that fibrous structures, uniformly elongated along the direction normal to the specimen surface, were formed on the diamond surfaces. Similar experiments for glasslike carbon resulted in conical structures with frizzy fibers at the tops. Transmission electron microscopy measurements indicated that the fibers formed on diamond consisted of randomly oriented diamond nanocrystals with diameters of less than 10 nm, while the conical structures formed on glasslike carbon consisted of graphite nanocrystals. Field emission measurements of the fibrous specimens exhibited better emission efficiency than untreated ones. The field emission electron microscopy of the fibrous glasslike carbon showed a presence of discrete electron emission sites at a density of approximately 10,000 sites/cm2.

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