Mechanochemical method of polishing a polycrystalline diamond coating

2021 ◽  
Author(s):  
Dmitriy Ohlupin ◽  
Al'bert Korolev ◽  
Il'ya Sinev
Keyword(s):  
Surface Roughness ◽  
Polycrystalline Diamond ◽  
Technological Problem ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Mechanochemical Method ◽  
Industrial Enterprises ◽  
High Processing ◽  
Brittle Destruction

The monograph presents a solution to the technological problem of polishing a polycrystalline diamond coating by a mechanochemical method in order to ensure the required surface roughness and high processing performance. The analysis of existing schemes and methods of polishing diamonds and diamond coatings is carried out. A technology for polishing diamond coatings with a metal brush is proposed, which provides brittle destruction of the vertices of large micro-roughnesses and graphitization of small micro-roughnesses. For researchers, postgraduates and specialists of industrial enterprises involved in the technology of polishing the surfaces of parts.

Effects of Various Seeding Methods on Multi-Layered Diamond Coatings Deposited via Hot Filament Chemical Vapor Deposition

2013 ◽  
Vol 845 ◽  
pp. 36-40
Author(s):  
Tze Mi Yong ◽  
Esah Hamzah
Keyword(s):  
Natural Diamond ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Columnar Structure ◽  
X Rays ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Good Adhesion ◽  
Hot Filament ◽  
Xrd Method

Multi-layer alternating nanocrystalline diamond (NCD) layer and polycrystalline diamond (PCD) layer was successfully deposited on pretreated tungsten carbide (WC) substrates with various seeding sizes (<0.1μm synthetic, <0.5μm synthetic, <0.25μm natural, <0.5μm natural, and <1μm natural) diamond with and without hammering by silicon carbide. X-rays penetrate through the coating to the substrate from XRD method was able to show strong peaks of diamond relative to WC despite the diamond film being 4μm thick only. It is found that substrates with no hammering produce stronger signals. The coating was cross sectioned and analysed using field emission scanning electron microscopy showing the multi-layer with NCD grains that has coalesced and columnar structure for PCD. None of the diamond coating delaminated during cross sectioning showing good adhesion. Raman was able to capture data from the 1-1.6μm thick NCD layer only while AFM measured the extreme low roughness of the NCD surface.

scholarly journals Influence of the surface microstructure on the adhesion of a CVD-diamond coating on steel with a CrN interlayer

2018 ◽  
Vol 190 ◽  
pp. 14008 ◽  
Author(s):  
Markus Prieske ◽  
Richard Börner ◽  
Andreas Schubert
Keyword(s):  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Surface Microstructure ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Surface Microstructures ◽  
The One ◽  
Cvd Diamond Coating ◽  
Surface Prediction ◽  
Steel Substrates

forming tool coating. Most of the forming tools are made of steel, so that especially the coatability of steel by a polycrystalline diamond coating would rise the range of fields of application. The polycrystalline CVD-diamond coatings are deposited by a laser induced plasma CVD process, without a vacuum chamber. Various surface microstructures were investigated regarding their influence on the residual stresses to prevent a flaking of the coating: on the one hand, deterministic structures generated by ultrasonic vibration assisted milling (UVAM) and on the other hand, stochastic structures manufactured by blasting and polishing processes. For the UVAM, a surface prediction tool was used to design the surface microstructure beforehand. All steel substrates (material no. 1.2379) were coated in one batch by high-power impulse magnetron sputtering with a chromium nitride coating with a thickness of 2.4 μm. The specimens were analysed by laser microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Raman spectroscopy. None of the microstructures investigated in this study was able to prevent delamination of the coating entirely. It could be shown that a roughness higher than Sa 0.1μm supports the interlocking between coating and surface as well as that sharp peaks inhibit a homogenous diamond coating deposition.

Effects of Two-Step DC Electrochemical Pretreatment of Fine Grinding WC-Co Tool Surface on Morphology and Quality of Diamond Coatings

2011 ◽  
Vol 337 ◽  
pp. 59-62
Author(s):  
Xiang Hui Zhang ◽  
Ling Wang ◽  
Jian Ping Long
Keyword(s):  
Surface Morphology ◽  
Direct Current ◽  
Arc Discharge ◽  
Etching Time ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Fine Grinding ◽  
Electrolytic Etching ◽  
Electrochemical Pretreatment

In the present investigation, diamond coating was deposited on fine grinding cemented carbide substrate by direct current arc discharge chemical vapor deposition. The effect of electrolytic etching time in the two-step electrochemical pretreatment process (firstly using electrolytic etching, and then using acid etching) on morphology and quality of the diamond coating were systemically studied. The surface morphology feature and quality of diamond coatings were characterized by means of Scanning Electron Microscope (SEM), laser Raman spectrometer respectively. The results showed that the electrolytic etching duration has distinctly effect on the quality and crystal features such as morphology, crystal type and grain size of diamond coating. It showed that as electrolytic current is direct current 3A, electrolytic etching time altering from 0.5 min to 7.5min, the surface morphology of diamond films gradually transition from microcrystalline cubic-octahedron to cauliflower type nanocluster, and further increase the electrolytic etching time, will lead to several negative effects on the quality and nucleation of the coatings which is not only retard the diamond nucleation, but also promote the formation of graphite.

Influence of Technical Parameters on the Residual Stress in the Diamond Coating

2012 ◽  
Vol 426 ◽  
pp. 85-88
Author(s):  
Hong Xiang Wang ◽  
Dun Wen Zuo ◽  
Chun Xu ◽  
Chun Zhou
Keyword(s):  
Residual Stress ◽  
Substrate Temperature ◽  
Compressive Stress ◽  
Crystalline Silicon ◽  
Volume Ratio ◽  
Chemical Vapor ◽  
Chamber Pressure ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Technical Parameters

The diamond coatings were prepared by hot filament chemical vapor deposition(HFCVD) on the mono-crystalline silicon substrates. The influence of the technical parameters such as methane volume ratio, substrate temperature and reaction pressure on the residual stress in the diamond coating was studied. The results showed that the residual stress in the coating was compressive stress in the range of parameters studied, and too high or too low substrate temperature, chamber pressure and methane volume ratio would all increase the residual compressive stress. This relationship can be explained by the influence of amorphous carbon content, vacancy density and grain size on the residual stress.

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.

Small Holes Fabrication on Soda Glass by Self-Elastic Polycrystalline Diamond Tool

2012 ◽  
Vol 516 ◽  
pp. 516-521
Author(s):  
Chung Chieh Cheng ◽  
Dong Yea Sheu
Keyword(s):  
Surface Roughness ◽  
Diamond Tool ◽  
Polycrystalline Diamond ◽  
The Self ◽  
High Quality ◽  
Drilling Tool ◽  
Drilling Tools ◽  
Absorbing Materials ◽  
New Type ◽  
Small Holes

This study describes a novel process to drill small holes in brittle materials such as glass, silicon and ceramic using a self-elastic polycrystalline diamond (PCD) drilling tool. In order to improve the surface roughness and reduce crack of the small holes, a new type of self-elastic PCD drilling tool equipped with vibration absorbing materials inside the housing was developed to fabricate small holes in glass in this study. The self-elastic PCD drilling tools could absorb the mechanical force by the vibration absorbing materials while the PCD tool penetrates into the small holes. Compared to conventional PCD drilling tools, the experimental results show that high-quality small holes drilled in glass can be achieved with cracking as small as 0.02mm on the outlet surface using the self-elastic PCD drilling tool.

A Truing Technique of Flattening Diamond Grains for Fabricating Microstructures with Fine Surfaces

2008 ◽  
Vol 389-390 ◽  
pp. 350-355
Author(s):  
Takeshi Harada ◽  
Takuya Semba
Keyword(s):  
Surface Roughness ◽  
Electrical Discharge ◽  
Diamond Tool ◽  
Electrical Discharge Machining ◽  
Polycrystalline Diamond ◽  
Mesh Size ◽  
Diamond Disk ◽  
Working Surface ◽  
Work Material ◽  
Tool Profile

A truing technique that can be used to shape the tip of an electroformed diamond tool into a hemisphere and flatten diamond grains on the tool working surface at the same level as the bond face was developed. A polycrystalline diamond disk whose top surface roughened by electrical discharge machining was partially flattened by grinding was used as a truer. Diamond grains on the tool working surface were successfully flattened along the hemispherical tool profile when the grains mesh size of #1000 was employed. In addition, a grinding test using glasslike carbon as a work material revealed that a surface roughness of less than 50 nm Rz could be obtained in both cases when moving the tool on contour and scanning paths.

scholarly journals Polishing of Black and White CVD Grown Polycrystalline Diamond Coatings

2018 ◽  
Vol 5 (2) ◽  
pp. 50-58
Author(s):  
Snigdha Roy ◽  
Vamsi K. Balla ◽  
Awadesh K. Mallik ◽  
Victor G. Ralchenko ◽  
Andrey P. Bolshakov ◽  
...  
Keyword(s):  
Polycrystalline Diamond ◽  
Diamond Coatings ◽  
Black And White
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