Stress in Diamond Coatings on Cutting Tools Deposited by Hollow Substrate Holder

2009 ◽  
Vol 407-408 ◽  
pp. 19-23
Author(s):  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Feng Xu ◽  
Chun Yang ◽  
Min Wang
Keyword(s):  
Substrate Temperature ◽  
Carbon Content ◽  
Compressive Stress ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Substrate Holder ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Ch4 Concentration

Chemical vapor deposition (CVD) diamond coatings were deposited on milling cutter substrate using a hollow substrate holder. The substrate is WC–Co cemented carbide contained 6% of cobalt concentration. Structures and stress state of diamond films were analyzed by scanning electron microscopy (SEM) and Raman spectroscopy. It was found that the diamond coating is of the same quality at the same cutting tool deposited on a hollow substrate holder. Diamond (sp3) bonds are better developed with substrate temperature of ~760°C. A higher or lower substrate temperature could lead to a higher non-diamond carbon content in the films. A higher substrate temperature could lead to a higher thermal stress. The compressive stress increases when the substrate temperature is higher or lower than 760°C. The concentration of amorphous phase in the coatings is low with CH4 concentration of 1.0% and 1.5%. A higher non-diamond carbon content and defects in the diamond coatings increase with the increase of CH4 concentration, which leads to the compressive stress value does not increase significantly under a high CH4 concentration.

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.

Mechanical Properties of Nano-Indentation of Diamond Coating in Infrared Window

2011 ◽  
Vol 381 ◽  
pp. 104-108
Author(s):  
Hong Xiang Wang ◽  
Dun Wen Zuo ◽  
Chun Xu
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Substrate Temperature ◽  
Crystalline Silicon ◽  
Volume Ratio ◽  
Chemical Vapor ◽  
Chamber Pressure ◽  
Diamond Coating ◽  
Micro Hardness ◽  
Diamond Coatings

Diamond coatings were prepared on mono-crystalline silicon by hot filament chemical vapor deposition (HFCVD). Hardness, elastic modulus and other mechanical properties of the diamond were analyzed by nanoindenter. The results showed that the process parameters such as chamber pressure, substrate temperature, methane volume ratio have a greater impact on the mechanical properties of the diamond coating. The micro-hardness and elastic modulus of the coating would both decrease with too high or too low substrate temperature, chamber pressure or volume ratio of methane. The results showed that when the substrate temperature is 750°C, champer pressure is 2.5kPa and methane volume ratio is 2%, the diamond coatings have high micro-hardness and elastic modulus.

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.

Analysis of Interlayer between WC–Co and CVD Diamond Film

2008 ◽  
Vol 375-376 ◽  
pp. 92-96 ◽  
Author(s):  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Min Wang ◽  
Feng Xu
Keyword(s):  
Cutting Tools ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Diamond Coatings ◽  
X Ray Diffraction ◽  
Raman Scattering Spectroscopy ◽  
Electron Probe Micro Analyzer ◽  
Mechanical Bond ◽  
Cvd Diamond Coating ◽  
Better Than

Electroplated Cr, Ni and Cu were used as interlayer for chemical vapor deposition (CVD) diamond coating on WC–Co cemented carbide cutting tools. The electroplated interlayers were studied by Scanning Electron Microscope (SEM), Electron Probe Micro Analyzer (EPMA) and X-ray diffraction (XRD). The CVD diamond coatings were studied by SEM and Raman Scattering Spectroscopy (Raman). The experimental results show that there is diffusion bonded interface between electroplated layer and WC-Co substrate after H plasma treatment, the bond between electroplated layers and WC-Co substrate changes from mechanical bond to metallurgical bond and the adhesion becomes stronger. Electroplated Cr interlayer forms new phases of Cr3C2 and Cr7C3 under CVD conditions, while electroplated Ni and Cu interlayers do not form carbides under CVD conditions. Cr carbides have good chemical compatibility to diamond, and they are propitious to diamond nucleation and growth during the deposition period. The diamond crystal microstructure, diamond quality and adhesion on Cr interlayer are better than those on electroplated Ni and Cu interlayers.

Effects of CH4 Concentration on CVD Diamond Coatings Deposited on Cemented Carbide Cutting Cools

2006 ◽  
Vol 532-533 ◽  
pp. 480-483 ◽  
Author(s):  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Min Wang ◽  
Feng Xu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Great Influence ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Cemented Carbide ◽  
Diamond Coatings ◽  
Ch4 Concentration

Chemical vapor deposition (CVD) diamond coatings were deposited on cemented carbide cutting cools by an electron-assisted hot filament chemical vapor deposition (EACVD) equipment developed by the authors. The CVD diamond coatings were studied by Scanning Electron Microscope (SEM) and Raman Scattering Spectroscopy (Raman). The experimental results show that CH4 concentration in the source gas performs great influence on the micro-structure, surface roughness, composition, residual stress and adhesion of the CVD diamond coatings. The increase of CH4 concentration results the change of diamond crystal from {111} orientation to {100} orientation, the decrease of the surface roughness and the increase of sp2 carbon in the CVD diamond coatings. A residual compressive stress exists in the CVD diamond coatings. The residual stress decreases with increasing CH4 concentration. A higher or lower CH4 concentration tends to reduce adhesion stress of the continuous CVD diamond coatings.

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.

Evaluation of Silicon Nitride Ceramic Cutting Tools with Diamond Coatings

2008 ◽  
Vol 591-593 ◽  
pp. 537-542 ◽  
Author(s):  
M.A. Lanna ◽  
A.M. Abrão ◽  
F. Levy Neto ◽  
Claudinei dos Santos ◽  
Cosme Roberto Moreira Silva
Keyword(s):  
Silicon Nitride ◽  
Flank Wear ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Carbon Powder ◽  
Diamond Coating ◽  
Machining Performance ◽  
Film Rupture ◽  
Composite Surface ◽  
Ceramic Tools

There is a substantial increase on carbon-carbon composites use for engineering applications, considering its high temperature properties and low specific mass. However the machining costs are relatively high, and new cutting tools, mainly ceramics, must be developed to overcome such difficulty, aiming cost reductions. In this work, silicon nitride based ceramics has been prepared , by pressureless sintering of silicon nitride powders and appropriate amounts of Al2O3,Ce2O3, Y2O3 and AlN. Cutting tools were prepared from the sintered materials, with geometry according to ISO1832. Selected cutting tools were also diamond coated by a hot filament-assisted Chemical Vapor Deposition (HFCVD) diamond coating process. Carbon Fiber Reinforced Carbon (CFRP) composites machining was performed, to evaluate the diamond coating influence on machining performance. After the tests, the uncoated tools presented severe flank wear and shorter life than the diamond coated ceramic tools. This flank wear is caused by the abrasive carbon powder generated during the facing operation. On CVD diamond coated α-SiAlON ceramic tools, no flank wear was observed, and the cutting edge remained unmodified, even for severe test conditions, such as high cutting length and speed. Carbon particles, originated from the machined composite, do not promotes diamond film rupture, but instead, acts as lubricant film and reduces composite surface initial roughness.

Silicon Nitride Tools Coated With Tic Or Tin Composite Diamond Structures

1995 ◽  
Vol 415 ◽  
Author(s):  
W.D. Fan ◽  
K. Jagannadham ◽  
J. Narayan
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Adhesion Properties ◽  
Tin Films ◽  
Composite Diamond ◽  
Diamond Paste

ABSTRACTComposite diamond coatings on Si3N4 substrates have been developed to minimize stresses/strains and improve wear and adhesion properties. The coatings consist of a first layer of discontinuous diamond crystallites which are anchored to the Si3N4 substrate by a second interposing layer of TiC or TiN film. A top third layer of continuous diamond film is grown epitaxially on the first layer. The diamond films and TiC or TiN films were deposited using hot filament chemical vapor deposition and laser physical vapor deposition, respectively. The TiC and TiN films were examined by X-ray diffraction. The diamond films were characterized by scanning electron microscopy and Raman spectroscopy. Adhesion of the diamond coatings was investigated using overlap polishing with diamond paste, wear against Al-12.5%Si alloy, and pull-test. The results show that after introducing an interposing layer of TiC or TiN, adhesion of diamond coatings on Si3N4 substrates is improved significantly. After polishing test against diamond paste for 4 hours, only 30% of diamond was retained with single diamond coating while 80% of diamond was found with TiN composite diamond coating. The mechanism of improvement of adhesion is discussed.

Highly adherent diamond coatings deposited onto WC-Co cemented carbides via barrier interlayers

1998 ◽  
Vol 13 (10) ◽  
pp. 2841-2846 ◽  
Author(s):  
J. M. Lopez ◽  
V. G. Babaev ◽  
V. V. Khvostov ◽  
J. M. Albella
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Cemented Carbides ◽  
Bonding Layer ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Diamond Deposition ◽  
Fine Grained ◽  
High Adhesion ◽  
Bond Layer

Diamond coatings have been deposited by plasma enhanced chemical vapor deposition (PCVD) onto WC-Co cemented carbides by use of specially developed barrier interlayers, well compatible with cemented carbides. The barrier interlayer comprises a Ti-based layer adjacent to the substrate, which completely prevents both substrate decarburization and Co diffusion from the substrate, and a diamond-bonding layer needed to obtain high adhesion to the diamond coating. The diamond-bond layer is obtained by seeding the surface with nanograined diamond particles by laser ablation. Diamond deposition under controlled parameters allows one to obtain fine-grained and uniform diamond coatings. The diamond coating obtained in this way has a high adhesion to the cemented carbide substrate due to the enhanced interaction through the nanograined diamond interlayer.

Simulation of Gas Flow Field in HFCVD System for CVD Diamond Growth

2010 ◽  
Vol 431-432 ◽  
pp. 21-24
Author(s):  
Huan Qing Lin ◽  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Chun Yang ◽  
Feng Xu
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Cutting Tool ◽  
Cvd Diamond ◽  
Diamond Growth ◽  
Substrate Holder ◽  
Diamond Coating ◽  
Simulation And Experiment ◽  
Cvd Diamond Coating ◽  
Gas Flow Field

The thermal blockage and thermal round flow in HFCVD system for CVD diamond growth will lead to un-stability of product quality. Finite element method has been used to simulate the gas flow field around the cutting tool substrate within a HFCVD diamond reactor. Experiments have been done to prove the simulation results. Excellent agreement between simulation and experiment was obtained by depositing of CVD diamond coated cutting tool. The thermal blockage and thermal round flow in HFCVD system decrease by using a hollow substrate holder. High quality CVD diamond coating can be obtained using a hollow substrate holder.

Sign in / Sign up

Export Citation Format

Share Document