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Brazing diamond tools were used to machining monocrystal sapphire dome. The effects of processing parameters on the cutting force, surface quality were researched. The results showed that the speed...

A CVD diamond coating tool with prismatic crystal structure was prepared by hot filament chemical vapor deposition (HFCVD) method to improve sapphire’s lapping efficiency. The full plastic removal ...

CVD diamond films were prepared on the cemented carbide substrate by hot filament chemical vapor deposition method. The diamond coatings were observed with SEM and Raman spectroscopy. The results s...

An effective pretreatment method of carbon fiber reinforced plastic (CFRP) aircraft skin was proposed. In this article, the function of the amino thermosetting abrasives entrained by the airflow on the CFRP aircraft skin is introduced and discussed to achieve the purpose of enhancing the coating adhesion and prolonging the service life. An orthogonal experiment with five factors and four levels was designed and carried out, including jet pressure, target distance and impact angle, moving speed and particle size. The best pretreatment process was obtained by analyzing surface morphology, wettability and adhesion. The erosion mechanism of CFRP coating pretreatment with abrasive impact was studied emphatically. The results show that the critical pressure for fiber damage is 0.4 MPa, and the better surface energy is 38.0 mN/m. Semi-ductile erosion has been identified as the main erosion mechanism of amino thermosetting abrasives eroding CFRP. Effective assurance was provided for the improved surface of the aircraft CFRP skin and enhanced coating adhesion in this study.

The surface and subsurface damage of monocrystalline germanium wafer directly affect the performance and life of the product, so it is necessary to reduce the occurrence of damage during the lapping and polishing process. The changes in ambient temperature and temperature in the process will affect the shape precision of the workpiece, and also influence the surface of the material and the quality of subsurface. In this paper, the angle polishing method was used to measure the subsurface damage of germanium wafer. The effects of different processing ambient temperature on the surface and subsurface damage of germanium wafer after lapping were compared and analyzed. The results show that compared with normal processing, the surface topography of germanium after low temperature lapping is flatter, less surface pits, more and more narrow shallow cracks, and less cracks on both sides of the cracks. The subsurface damage depth can be reduced effectively by low temperature processing. The shapes of subsurface crack are mainly line, herringbone, and dendrimer.

CVD diamond is an ideal processing material which is suitable for the Micro-Electro-Mechanical System parts, such as microgears, for its excellent performance. In this article, the masks for duplic...

Boronizing treatment was done to form a boride surface layer well bonded with cemented carbide substrate. Multilayer microcrystalline diamond (MCD) and nanocrystalline diamond (NCD) coatings were prepared on the boronizing cemented carbide substrate by hot filament chemical vapor deposition (HFCVD) method. The surface and the cross section micrograph, coating component, hardness and adhesion of the as-deposited diamond coatings were observed with a SEM, Raman spectroscopy, nano-indenter and a Rockwell hardness tester accordingly. The results show that the MCD coating consists of well-faceted grains and the hardness of the MCD coating is about 85GPa. The NCD coating has morphological features with grain sizes of several tens of nanometer. The hardness of the NCD coating is about 52GPa. The boron doping of cemented carbide substrate can improve the fracture strength of the diamond film to some extent, and the adhesion of multilayer NCD/MCD coating is better than that of monolayer MCD and monolayer N...

High-quality boron-doped nanocrystalline diamond (BDND) film was fabricated on mesh titanium substrate using hot filament chemical vapor deposition (HFCVD) system. Raman, X-ray diffraction (XRD), and scanning electron microscopy (SEM) spectroscopy were used to analyze the microstructure of the mesh Ti/BDND electrode. The SEM images show different parts of the mesh electrode surface are fully covered by the diamond film and particle sizes of that are nearly less than 1 μm on average. Additionally, the diamond film of the prepared electrode surface is relatively of high quality and the mesh electrode has a relatively small residual stress from Raman and XRD spectra, respectively. Cyclic voltammograms indicate that the mesh electrode has wide potential window, low background current and stable electrochemical properties in H2SO4 solution, suggesting that the prepared electrode is suitable for the application of wastewater treatment. The COD removal rate of the prepared mesh electrode increases by 10....

Boron-doped nanocrystalline diamond (BDND) films were prepared on Ti substrate by hot filament chemical vapor deposition (HFCVD) method. The morphology, phases and quality of the BDND films were characterized by Scanning electron microscopy, X-Ray diffraction, and Raman spectroscopy. Cyclic voltammograms indicated that the BDND electrodes had wide electrochemical window, low background current and good electro-oxidation performance of phenol solution. The effects of operative parameters like current density and pH initial were investigated. The results show that both of the two variables have significant influence on the degradation performance of the organic pollutants. High COD removal can be achieved using high current density in acid solutions, and there exists optimal values of both parameters considering the current efficiency and operation economics.

Hot-filament chemical vapor deposition (HFCVD) method was used to prepare aggregate spherical, pyramid and plane texture of micro-nano crystal diamond films on YG6 substrate surface by controlling preparation process parameters. The film surface morphology was observed using SEM. Texture type was inferred from XRD and Raman spectrum analysis. Friction and wear test was carried out innovatively using micro-nano crystal diamond film rub against single crystal sapphire. The micro-nano diamond particulates’ effect of friction on sapphire was compared. The results indicated that plane textured micro-crystal diamond film had larger average friction coefficient and better removal performance.