Investigation of Thermo-Chemical Polishing of CVD Diamond Film

2007 ◽  
Vol 329 ◽  
pp. 195-200 ◽  
Author(s):  
Wen Chen Chou ◽  
Choung Lii Chao ◽  
Hsi Hsin Chien ◽  
Kung Jeng Ma ◽  
Hung Yi Lin
Keyword(s):  
Diamond Film ◽  
Material Removal ◽  
Removal Rate ◽  
High Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Chemical Polishing ◽  
Machined Surface ◽  
Cvd Diamond Film ◽  
Very High

ZnO/Diamond structure has attracted a lot of attentions and heavy investment recently just because diamond has the capability of producing very high surface acoustic wave (around 10,000m/s). In this present study, the microwave chemical vapor deposition (CVD) method was employed to produce diamond films on silicon single crystal. Thermo-chemical polishing experiments were then conducted on the obtained diamond films. The underlying material removal mechanisms, microstructure of the machined surface and related machining conditions were also investigated. Thermo-chemical polishing was proved to be able to remove the diamond film very effectively (4.8μm deep of diamond film was removed in 30 minutes when polishing at 550oC and 5.7m/s). The material removal rate was increased with polishing speed and pressure. Higher polishing temperature would improve the chemical reaction and result in better surface finish.

Study on EDM Polishing of CVD Diamond Films

2006 ◽  
Vol 315-316 ◽  
pp. 464-468 ◽  
Author(s):  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Min Wang ◽  
Feng Xu ◽  
Xiang Feng Li
Keyword(s):  
Diamond Film ◽  
Discharge Current ◽  
Material Removal ◽  
Diamond Films ◽  
Film Surface ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Machined Surface ◽  
Cvd Diamond Film ◽  
Pulse On Time

Chemical vapor deposition (CVD) diamond is known for its superior characteristics such as hardness, toughness and wear resistance. However, due to these factors, machining CVD diamond is a difficult material removal process. A new technique to polish CVD diamond film efficiently is reported in the present paper. In the CVD deposition process, boron was doped into diamond to fabricate high-quality semi-conductive film, which make it possible to machine diamond film by electro discharged machining (EDM) method. The relationship between EDM parameter and removal processing was investigated in details. The machined surface of boron doped (B-doped) diamond films was studied by Scanning Electron Microscope (SEM) and Raman Scattering Spectroscopy (Raman). The experimental results show that EDM polishing is a highspeed material removal and low cost method for CVD diamond polishing. When the discharge current and pulse-on time increase in a certain range, the cutting-off speed and roughness will increase correspondingly. The roughness of EDM polished CVD diamond film surface is Ra<0.5μm when the discharge current is at 4A and pulse-on time is at 200μs.

Chemical Mechanical Polishing Slurries for Chemically Vapor-Deposited Diamond Films

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Zewei Yuan ◽  
Zhuji Jin ◽  
Youjun Zhang ◽  
Quan Wen
Keyword(s):  
Potassium Permanganate ◽  
Surface Finish ◽  
Diamond Film ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Mechanical Polishing ◽  
Potassium Ferrate ◽  
Cvd Diamond Film

The objective of this study is to investigate slurries for chemical mechanical polishing (CMP) of chemically vapor-deposited (CVD) diamond films based on the principle of thermokinetics combined with physical and chemical properties. The study uses the mechanical work, surface energy and oxidability of a slurry with diamond carbon as the main physical-chemical indicators in selecting the slurries. The study indentifies 10 CMP slurries of different oxidants, such as potassium ferrate, potassium permanganate, chromium trioxide and potassium dichromate, for CVD diamond film polishing. Prior to a CMP process, prepolishing with a boron carbide plate is performed to prepare a CVD diamond film with acceptable surface finish and flatness. After polishing with the CMP process a CVD diamond film is examined with optical microscopy, surface profilometry, atomic force microscopy and X-ray photoelectron spectroscopy for information on surface finish and quality, material removal and mechanisms. The study demonstrates that among the ten CMP slurries, the one with potassium ferrate as an oxidant provides the highest material removal rate of 0.055 mg/hour, and the best surface finish (Ra = 0.187 nm) and surface quality (no surface scratches nor pits), which is followed by potassium permanganate. It then discusses how mechanical stress may promote the chemical oxidation of an oxidant with diamond by forming “C-O” and “C=O” on diamond surface. The study concludes that chemical mechanical polishing is effective for CVD diamond films.

Deposition and Application of CVD Diamond Film on the Interior-Hole Surface of Shaped-Wire Drawing Die

2012 ◽  
Vol 217-219 ◽  
pp. 1022-1027
Author(s):  
Liu Jin Bian ◽  
Zi Chao Lin ◽  
Fang Hong Sun ◽  
Song Shou Guo
Keyword(s):  
Surface Quality ◽  
Diamond Film ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Wire Drawing ◽  
Drawing Die ◽  
Before And After ◽  
Cvd Diamond Film ◽  
Drawing Dies

Abstract：The shaped-wire drawing dies are used more and more popularly in the metal product industry for several advantages of locked structure. In present investigation, a layer of CVD diamond film is deposited on the interior-hole surface of shaped-wire drawing die using a hot filament chemical vapor deposition (HFCVD) method, followed by a surface polishing process, aiming at further prolonging its working lifetime of shaped-wire drawing dies and improving the surface quality of produced wires. The scanning electron microscopy (SEM), surface profiler and Raman spectroscopy are adopted to present the characterization of both as-deposited CVD diamond films before and after polishing. Furthermore, the performance of as-fabricated CVD diamond coated drawing dies is examined in the practical production process. The results show that as-deposited CVD diamond films are homogeneous and the working surface is smoother after polishing. Comparing with the conventional shaped drawing dies, the working lifetime of the diamond coated shaped-wire drawing dies can be increased by a factor of above 10, and the shaped wires with higher surface quality can be obtained.

Selective Growth of B-Doped Diamond on Si-Doped Diamond Film

2012 ◽  
Vol 217-219 ◽  
pp. 1013-1017
Author(s):  
Y.X. Cui ◽  
B. Shen ◽  
F.H. Sun ◽  
Z.M. Zhang
Keyword(s):  
Diamond Film ◽  
Sacrificial Layer ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Selective Area ◽  
Si Doped ◽  
Cvd Diamond Film ◽  
Hot Filament ◽  
Area Deposition

Si doped CVD diamond films are prepared on Si substrate by means of hot filament chemical vapor deposition (HFCVD) through adding tetraethoxysilane (TEOS) into acetone as source of reactant gas during the growth process. The samples of diamond films are investigated by scanning electron micrograph (SEM), Raman spectrum, X-ray diffractometry (XRD) and surface profiler. The experimental results show that compared with pure diamond film, Si doped CVD diamond film exhibits grain refinement and smoother surface. Then selective area deposition (SAD) of B-doped diamond films are achieved on both Si doped CVD diamond film and pure CVD diamond film with silicon dioxide layer as sacrificial layer. SEM investigation demonstrates that the boundary of patterning on pure diamond film is rather fuzzy while on pure diamond film it is trim and distinct, which is mainly attributed to the relatively low surface roughness.

An Investigation Into Non-Conventional Machining of Metal Matrix Composites

2019 ◽  
pp. 175-187
Author(s):  
Divya Zindani ◽  
Kaushik Kumar
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Material Removal ◽  
Removal Rate ◽  
Matrix Composites ◽  
Abrasive Water Jet ◽  
Machined Surface ◽  
Mechanical Erosion ◽  
Conventional Machining ◽  
Very High

One of the recently developing fields is that of non-traditional machining of particle reinforced metal matrix composites. The complexity associated with traditional machining of particle reinforced metal matrix composite is very high, and therefore, the researchers have begun to show more focus towards non-traditional machining. In the present work, the investigation has been carried out for non-traditional machining such as laser beam machining, electro-chemical machining, abrasive water jet machining, and electro-chemical discharge. Material removal rate, surface finish, and the mechanism of machining has been studied for each of the aforementioned processes. The main material removal mechanisms as has been identified are melting, mechanical erosion, vaporization, and chemical dissolution. The investigation reveals that the major reasons for the damage of the machined surface are the presence of reinforcement particles and thermal degradation.

Uniform Deposition of Chemical Vapor Deposition Diamond Films on Slender Tungsten Wires

2016 ◽  
Vol 848 ◽  
pp. 618-623
Author(s):  
Xin Chang Wang ◽  
Xiao Tian Shen ◽  
Tian Qi Zhao ◽  
Fang Hong Sun ◽  
Bin Shen
Keyword(s):  
Chemical Vapor Deposition ◽  
Diamond Film ◽  
Vapor Deposition ◽  
High Surface ◽  
Diamond Films ◽  
Surface Hardness ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Diamond ◽  
Substrate Adhesion ◽  
Film Substrate

In the present study, high-quality chemical vapor deposition (CVD) micro-crystalline diamond (MCD) film was successfully deposited on the surface of the Φ0.5 mm×120 mm tungsten wire using a special designed graphitic jig for supporting the substrate and a two-step deposition procedure for guaranteeing the uniformity of as-deposited diamond film. It is proved that as-deposited film indeed presented much more uniform thickness than that obtained using a conventional jig described in the previous literature, and a very thick WC interlayer spontaneously formed between the substrate and the diamond film, which together with as-deposited MCD film have significant effects on mechanical properties of the wire. Generally speaking, the coated wire remains extremely high surface hardness of the MCD film and considerable toughness of the substrate, along with favorable film-substrate adhesion. It is recognized that these the coated tungsten wires have broad application prospects, but the technologies for depositing diamond films that are thick enough on even longer and thinner wires still need further investigation.

A Study of Thermal-Chemical Polishing for CVD Diamond Thin Films

2009 ◽  
Vol 76-78 ◽  
pp. 207-211
Author(s):  
Pei Lum Tso ◽  
Thing Ming Wang
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Material Removal Rate ◽  
Vapor Deposition ◽  
Material Removal ◽  
Removal Rate ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Chemical Polishing ◽  
Diamond Thin Films

Chemical vapor deposition (CVD) diamond thin films are widely used in modern industries. However, due to the nature of polycrystalline, thin films are required to be polished in the final process to increase its surface quality. Thermal-chemical polishing is known for its less processing time and low cost. In this paper, the experiments are carried out to observe the effect of processing conditions such as temperature, rotational speed, polishing pressure, and substrate material on the surface roughness and on the material removal rate of the chemical vapor deposition diamond (CVDD). At the same time, the processing mechanism for this thermal-chemical polishing is investigated, and a polishing model is built for comparison with the experiment results. The results show that the material removal rate is affected mainly by the diffusing rate in the Fe-C polishing system. By using the model, the approximate value of material removal rate can be calculated according to the polishing temperature.

Chemical-Assisted Mechanical Polishing of Diamond Film on Wafer

2006 ◽  
Vol 505-507 ◽  
pp. 1225-1230 ◽  
Author(s):  
Hong Ho Cheng ◽  
C.C. Chen
Keyword(s):  
Surface Roughness ◽  
Potassium Permanganate ◽  
Diamond Film ◽  
Removal Rate ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Industrial Applications ◽  
Potassium Persulfate ◽  
Ceramic Plate ◽  
Cvd Diamond Film

Diamond has been well recognized a strategic engineering material. It possesses excellent physical and chemical properties including the highest hardness and thermal conductivity, and good resistance to chemical erosion. Although CVD diamond film has good potential outstanding properties, its industrial applications have been limited by the non-uniform thickness and rough surface. In the current study, the CVD diamond film is polished by the chemical-assisted mechanical method with different slurries. These slurries contain strong oxidation chemical and diamond powder. During the process, the diamond film was held against the rotational ceramic plate with transverse oscillation at 90 °Cor lower. The profilometer, atomic force microscope and scanning electron microscope were used to evaluate the surface integrity of the diamond films before and after polishing. Based on the experimental results, the slurry containing potassium persulfate (K2S2O8) produces the highest material removal rate while potassium permanganate (KMnO4) develops the best local surface roughness. The strategy of using potassium persulfate for coarse polishing followed by potassium permanganate for fine polishing yields the diamond films of the best global surface roughness. The average surface roughness of the diamond film produced by the proposed technique is below 10 nm after 5 hours.

EDM with USM Combination Process of Sintered NdFeB Permanent Magnet

2010 ◽  
Vol 44-47 ◽  
pp. 1066-1069
Author(s):  
Li Li ◽  
Li Ling Qi ◽  
Zong Wei Niu
Keyword(s):  
Permanent Magnet ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Dielectric Fluid ◽  
Machined Surface ◽  
Combination Process ◽  
Electro Discharge Machining ◽  
Ndfeb Permanent Magnet ◽  
Machining Characteristics

This paper presents an experimental investigation of the machining characteristics of sintered NdFeB permanent magnet using a combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). Concentration of abrasive in the dielectric fluid is changed to explore its effect on the material removal rate (MRR). MRR of EDM /USM, conventional EDM are compared, machined surface characteristics are also compared between them. It is concluded that the combination EDM/USM process can increase the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate abrasive concentration can improve its machining efficiency.

Nano-Crystalline Diamond Films Deposited on Copper Substrate by MPCVD Method

2011 ◽  
Vol 117-119 ◽  
pp. 1310-1314
Author(s):  
Xing Rui Li ◽  
Xin Wei Shi ◽  
Ning Yao ◽  
Xin Chang Wang
Keyword(s):  
Diamond Film ◽  
Deposition Time ◽  
Microwave Plasma ◽  
Copper Substrate ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Annealing Process ◽  
Adhesive Properties ◽  
Plasma Chemical Vapor Deposition ◽  
Nano Crystalline

Nano-crystalline diamond (NCD) films with good adhesion were deposited on flexible copper substrate with Ni interlayer by Microwave Plasma Chemical Vapor Deposition (MPCVD). In this paper, two-stage method was used to improve the adhesion between the copper substrates and the diamond films. The effect of deposition time of the first stage on the morphology, crystal structure, non-diamond phase and adhesive properties of diamond films was investigated. The performance and structure of the diamond films were studied by Scanning Electron Microscope (SEM), Raman Spectroscopy (Raman) and X-Ray Diffraction (XRD). The results showed that the films were nano-crystalline diamond films positively. Impress method was used to examine the adhesion between diamond film and the substrate. When deposition time is 1.5h, the adhesion between diamond film and the copper substrate is better than the others. When it was 2.5h or longer, because the graphite layers existed as intermediate, the adherence between the diamond films and copper substrates was very poor. Therefore, the diamond films were easily peeled off from the substrates. Otherwise, the second stage called annealing process after the deposition played an important role to the adhesion. The films would be easily peeled off by curling without the annealing process.

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