scholarly journals Interaction of Methane Concentration and Deposition Temperature in Atmospheric Laser Based CVD Diamond Deposition on Hard Metal

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 537
Author(s):  
Markus Prieske ◽  
Sven Müller ◽  
Peer Woizeschke
Keyword(s):  
Coating Thickness ◽  
Deposition Temperature ◽  
Laser Scanning ◽  
Methane Concentration ◽  
Chemical Vapour ◽  
Cvd Diamond ◽  
Hard Metal ◽  
Process Temperature ◽  
Diamond Coatings ◽  
Methane Concentrations

For laser-based plasma chemical vapour deposition (CVD) of diamond on hard metal at atmospheric pressure, without a vacuum chamber, the interaction between the deposition temperature and the methane concentration has to be understood to adjust the coating thickness, deposition duration, and medium diamond crystal size. The hypothesis of this study is that a wider range of methane concentrations could be used to deposit microcrystalline diamond coatings due to the increasing etching and deposition rates with rising deposition temperatures. The deposition of the CVD diamond coatings was carried out on K10 hard metal substrates. The process temperature and the methane concentration were varied from 650 to 1100 °C and from 0.15% to 5.0%, respectively. The coatings were analysed by scanning electron and 3D laser-scanning confocal microscopy, energy dispersive X-ray and micro-Raman spectroscopy, as well as cryofracture-based microscopy analysis. The results showed that microcrystalline diamond coatings could be deposited in a wider range of methane concentrations when increasing the process temperature. The coating thickness saturates depending on the process temperature even though the methane concentration constantly increases. The coating thickness increases with an increasing deposition temperature until the cobalt diffusion hinders the deposition at the process temperature of 1100 °C.

scholarly journals Investigation of Friction and Wear Performance of Diamond Coating under Si3N4 Friction Pair

Mechanika ◽  
2021 ◽  
Vol 27 (5) ◽  
pp. 421-428
Author(s):  
Feng Lu ◽  
Yueyao Wang ◽  
Huixin Li ◽  
Tianen Hao ◽  
GuangYu Yan ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Methane Concentration ◽  
Friction Pair ◽  
Chemical Vapor ◽  
Wear Test ◽  
Chemical Vapor Deposition Method ◽  
Diamond Coatings ◽  
Raman Spectrometry ◽  
Lubrication Conditions ◽  
Methane Concentrations

In this study, diamond coatings were deposited through the hot filament chemical vapor deposition method on cemented carbide under different methane concentrations, ranging from 1% to 5%, to analyze the performance of the diamond coatings under different loads and lubrication conditions . Friction and wear tests were carried out using ball-disk friction and wear tester under different loads and lubrication conditions. Scanning electron microscopy, high-resolution Raman spectrometry, optical microscopy, and a surface profiler were used to observe the surface morphology and quality of the coatings after the wear test. The results revealed that the coating prepared under 3% methane concentration was more stable during the friction test than that prepared under other methane concentrations. In addition, the coating prepared under 5% methane concentration had poor adhesion and experienced failure under excessive load. Furthermore, lubricating the friction surface with water effectively reduced the formation of abrasive wear and the friction coefficient, and thus the sample reached the stable stage faster. In addition, the wear rate of the coating under wet condition was approximately 4–5 times less than that under dry friction conditions.

scholarly journals Chemical vapour deposition of diamond using low pressure flat combustion flame

2006 ◽  
Vol 71 (2) ◽  
pp. 197-202
Author(s):  
Miroljub Vilotijevic ◽  
Nebojsa Grahovac ◽  
Ljiljana Milovanovic ◽  
Slobodan Marinkovic
Keyword(s):  
Chemical Vapour Deposition ◽  
Coating Thickness ◽  
Vapour Deposition ◽  
Cutting Tool ◽  
Chemical Vapour ◽  
Low Pressure ◽  
Diamond Coatings ◽  
Flat Flame ◽  
Combustion Flame ◽  
Special Apparatus

Diamond coatings were deposited onto Mo and WC-Co substrates using a low pressure premixed acetylene-oxygen flat flame by means of a special apparatus operating at 50 mbar. Uniform diamond coatings containing significant amounts of non-diamond carbon were deposited over areas of ?7 cm2 onto Mo substrates, the coating thickness after 1 h deposition amounted to ?1 ?m. Upon machining an Al-12 % Si alloy under identical conditions, the diamond coated WC-Co cutting tool inserts showed 30 % less wear than the as-received inserts.

scholarly journals Murakami and H2SO4/H2O2 Pretreatment of WC-Co Hard Metal Substrates to Increase the Adhesion of CVD Diamond Coatings

1995 ◽  
Vol 05 (C5) ◽  
pp. C5-753-C5-760 ◽  
Author(s):  
R. Haubner ◽  
S. Kubelka ◽  
B. Lux ◽  
M. Griesser ◽  
M. Grasserbauer
Keyword(s):  
Cvd Diamond ◽  
Hard Metal ◽  
Diamond Coatings ◽  
Metal Substrates ◽  
H2o2 Pretreatment

scholarly journals In-Situ Friction Monitoring of Self-Mated CVD Diamond Coatings Using Acoustic Emission

2006 ◽  
Vol 514-516 ◽  
pp. 749-753
Author(s):  
C.S. Abreu ◽  
Filipe J. Oliveira ◽  
J.R. Gomes ◽  
Manuel Belmonte ◽  
A.J.S. Fernandes ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Microwave Plasma ◽  
Normal Load ◽  
Chemical Vapour ◽  
Cvd Diamond ◽  
Ambient Atmosphere ◽  
Diamond Coatings ◽  
Ae Signal ◽  
State Regime

In-situ measurements of acoustic emission (AE) in self-mated tribological pairs of CVD diamond coated silicon nitride (Si3N4) were made with the purpose of investigating the relationship between AE signal and friction events. A good correlation is found between the energy dissipation/emission processes, therefore enabling the possibility of monitoring the different friction regimes occurring during the sliding contact of microcrystalline diamond (MCD) coatings. Deposition of MCD on flat and ball-shaped Si3N4 samples was accomplished using microwave plasma assisted chemical vapour deposition (MPCVD) with H2/CH4 gas mixtures. The friction behaviour of self-mated MCD coatings was assessed using a reciprocating ball-on-flat geometry. The tests were run in ambient atmosphere without lubrication, the frequency (1Hz) and stroke (6mm) were kept constant while the applied normal load varied in the range 10-80N. The microstructure, surface topography and roughness of the MCD coatings were characterised by SEM and AFM techniques. The diamond quality was assessed from micro-Raman spectroscopy. The friction evolution was characterised by a short running-in period where the main feature is a sharp peak reaching values as high as approximately 0.6 followed by a steady-state regime with very low values in the range 0.03-0.04.

CVD Diamond Coatings for Machining

2006 ◽  
Vol 526 ◽  
pp. 55-60 ◽  
Author(s):  
D. Moulin ◽  
O. Raymond ◽  
P. Chevrier ◽  
Paul Lipiński ◽  
Thierry Barre
Keyword(s):  
High Performance ◽  
Metal Cutting ◽  
Thermal Stresses ◽  
Chemical Vapour ◽  
Surface Preparation ◽  
Deposition Process ◽  
Cvd Diamond ◽  
Tool Geometry ◽  
Diamond Coatings ◽  
Machined Surface

Machining of modern materials requires high performance tools. More than 60% of metal cutting tools used are coated to limit abrasive wear. As the harder material known to man, diamond and consequently Chemical Vapour Deposited (CVD) diamond coatings allow to increase performances of tungsten carbide tools, i.e. tool life, machined surface quality, and to decrease costs. However, CVD diamond coated tools quality is very dependent on the surface preparation as much as the fabrication process parameters. This paper aims to discuss the influence of pretreatments before deposition, and thermal stresses induced by the cooling operation. Diamond deposition process is described emphasizing the role of every step and its function. Some numerical simulations of the residual stresses at the interface are presented, enlightening that tool geometry is an important factor while using a coating, and that tools must be designed for the diamond coating.

Effects of thickness and cycle parameters on fretting wear behavior of CVD diamond coatings on steel substrates

2010 ◽  
Vol 205 (1) ◽  
pp. 158-167 ◽  
Author(s):  
Qiuping Wei ◽  
Z.M. Yu ◽  
Michael N.R. Ashfold ◽  
Z. Chen ◽  
L. Wang ◽  
...  
Keyword(s):  
Wear Behavior ◽  
Cvd Diamond ◽  
Fretting Wear ◽  
Diamond Coatings ◽  
Steel Substrates

Scanning Scratch Tests for Evaluating the Adhesion of Thin Oxide Films on Stainless Steel

1994 ◽  
Vol 356 ◽  
Author(s):  
V. A. C. Haanappel ◽  
H. D. van Corbach ◽  
T. Fransen ◽  
P. J. Gellings
Keyword(s):  
Mechanical Properties ◽  
Growth Rate ◽  
Stainless Steel ◽  
Film Thickness ◽  
Critical Load ◽  
Deposition Temperature ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Thin Oxide Films ◽  
Type Aisi

AbstractAmorphous alumina films were deposited by metal-organic chemical vapour deposition (MOCVD) on stainless steel, type AISI 304. The MOCVD experiments were performed in nitrogen at low pressure (0.17 kPa (1.25 torr)).The effect of deposition temperature (200 − 380 °C), growth rate, film thickness, and post-deposition thermal treatment on the mechanical properties was studied. The experiments were performed with a scanning-scratch tester. The experiments are based on the estimation of the film adhesion to the substrate by determining a critical load, Lc: the load where the film starts to spall or to delaminate.The best mechanical properties were obtained with unannealed samples. After thermal annealing the critical load decreases. Regarding the unannealed samples, the critical load increased with increasing film thickness. The deposition temperature and the growth rate had no effect on the critical load.

A spectroscopic study of optical centers in diamond grown by microwave-assisted chemical vapor deposition

1990 ◽  
Vol 5 (11) ◽  
pp. 2507-2514 ◽  
Author(s):  
A. T. Collins ◽  
M. Kamo ◽  
Y. Sato
Keyword(s):  
Chemical Vapor Deposition ◽  
Radiation Damage ◽  
Single Crystals ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Edge Emission ◽  
Microwave Assisted ◽  
Bright Blue ◽  
Methane Concentrations

Absorption and cathodoluminescence spectra have been recorded for single crystals of diamond and polycrystalline films of diamond, grown by microwave-assisted chemical vapor deposition (CVD) using methane and hydrogen. The investigation has been carried out to see to what extent the properties of CVD diamond are similar to those of conventional diamond, and to what extent they are unique. Studies have been made of the as-grown material, which has not been intentionally doped, and also samples that have been subjected to radiation damage and thermal annealing. The single crystals grown using methane concentrations of 0.5 to 1.0% exhibit bright blue “band A” emission and also intense edge emission, similar to the cathodoluminescence spectra of some natural type IIa diamonds. This implies that the crystals are relatively free from structural and chemical defects, a conclusion which is reinforced by the absence of any zero-phonon lines in the absorption spectra of crystals which have been subjected to radiation damage and annealing at 800 °C. Before radiation damage the spectrum does, however, reveal an absorption which increases progressively to higher energies, and which may be associated with sp2-bonded carbon. The Cathodoluminescence spectra after radiation damage indicate that the crystals contain some isolated nitrogen, and the detection of H3 luminescence, following thermal annealing at 800 °C, demonstrates for the first time that these samples contain small concentrations of nitrogen pairs. All of the polycrystalline films, grown using methane concentrations between 0.3 and 1.5%, have an absorption which increases progressively to higher energies, and which again is attributed to sp2-bonded carbon. This absorption is stronger in the films grown using higher methane concentrations. Films grown at a methane concentration of 0.3% also exhibit bright blue cathodoluminescence, although the edge emission is undetectably weak. The use of higher methane concentrations produces films with evidence in the cathodoluminescence spectra of nitrogen + vacancy and nitrogen + interstitial complexes, as well as optical centers unique to CVD diamond. One particular defect produces an emission and absorption line at 1.681 eV. By implanting conventional diamonds with 29Si ions it has been confirmed that this center involves silicon, and it has been shown that the 1.681 eV luminescence is relatively more intense in implanted diamonds which have a high concentration of isolated nitrogen.

scholarly journals Effect of Deposition Temperature on Self-Catalyzed ZnO Nanorods via Chemical Vapour Deposition Method

2018 ◽  
Vol 11 (1) ◽  
pp. 209 ◽  
Author(s):  
Shafinaz Sobihana Shariffudin ◽  
Puteri Sarah Mohamad Saad ◽  
Hashimah Hashim ◽  
Mohamad Hafiz Mamat
Keyword(s):  
Chemical Vapour Deposition ◽  
Deposition Temperature ◽  
Vapour Deposition ◽  
Zno Nanorods ◽  
Chemical Vapour ◽  
Catalyst Layer ◽  
Deposition Method ◽  
Current Increase ◽  
Axis Orientation ◽  
Chemical Vapour Deposition Method

The morphological, structural, optical and electrical properties of ZnO nanorods are investigated as a function of deposition temperature. The ZnO nanorods were grown on ZnO seed catalyst layer at temperatures between 750oC – 825oC using thermal chemical vapour deposition method.  Sample deposited at 825oC showed the highest crystalline orientation. The FE-SEM micrographs and the intense peak along (002) direction in the XRD spectra of this sample implied that the nanorods possess c-axis orientation. PL spectra showed two common ZnO peaks which centered at 380 nm and 540 nm. Two-point probe I-V measurement revealed ohmic behaviour with the gold metal contact, whereby the current increase with the deposition temperature.

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