Papers by Keyword: CVD Diamond

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Authors: X. Zhou, G.D. Watkins, K.M. McNamara Rutledge
Authors: Mariana A. Fraga, Andre Contin, Graziela S. Savonov, Divani C. Barbosa, Rodrigo S. Pessoa, Vladimir J. Trava Airoldi
Abstract: The growth of diamond films on different substrates has been studied extensively to support the emerging technologies ranging from mechanical to nano/microelectronics. It is known that the performance of these applications is affected by diamond film properties, such as structure and morphology. Using chemical vapor deposition (CVD) technique, we have deposited ultrananocrystalline diamond (UNCD) and microcrystalline diamond (MCD) films on 4H-SiC substrates and investigated their basic material properties. The understanding and exploitation of the material properties are fundamental to evaluate the potential of UNCD-on-SiC and MCD-on-SiC structures for fabrication of electronic devices and sensors.
Authors: Xi Zhong An, Guo Quan Liu, Chao Li
Abstract: The growth of nano CVD diamond films on low index faces such as (111) face and (100) face under different proposed surface chemical reaction model was simulated by using Kinetic Monte Carlo (KMC) method from atomic scale. The results, for example the influence of deposition time t, substrate temperature Ts, and atomic hydrogen concentration [H] on the film deposition rate, surface roughness, and H embedded in the film under different processing conditions, were systematically analyzed and compared. And the adsorption of various species on {111}-oriented diamond cluster was preliminarily computed from electronic scale by Local Density Approximation (LDA) method to assist understanding the surface adsorption mechanism. It is indicated that the film morphology and quality obtained from atomic scale KMC simulation varies according to the chemical reaction models. And our initial electronic scale computation on {111}-oriented diamond cluster showed that single-carbon species can be adsorbed on the activated site more easily than double-carbon species and the former will result in a more stable state than the latter. In order to reveal the nano CVD diamond film growth mechanism, more work about various species adsorption on many different morphological CVD diamond surfaces is needed.
Authors: S.N. Marinkovic
Authors: M. Boutinguiza, F. Quintero, Manuel Belmonte, A.J.S. Fernandes, Florinda M. Costa, Rui F. Silva, Juan Pou, Mariano Pérez Amor
Authors: D. Moulin, O. Raymond, P. Chevrier, Paul Lipiński, Thierry Barre
Abstract: 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.
Authors: R.A. Campos, A. Contin, Vladimir J. Trava-Airoldi, J.R. Moro, D.M. Barquete, Evaldo Jose Corat
Abstract: Silicon Nitride is largely used as the base material to manufacture cutting tools. Due to its low thermal expansion coefficient it is ideal candidate for CVD diamond deposition. In this work, we functionalized the surface of silicon nitride inserts (Si3N4) with a polymer (PDDA Poly (diallyldimethylamonium chloride - Mw 40000)) to promote seeding with nanodiamond particles. The seeding was performed in water slurry containing 4 nm diamond particles dispersed by PSS Poly (sodium4-styrenesulfonate) polymer. CVD diamond films, with high nucleation density, were deposited in a hot filament reactor. Film morphology was characterized by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Diamond film quality was determined by Raman Spectroscopy. CVD diamond film adherence was evaluated using Rockwell C indentation.
Authors: D.T. Britton, A. Hempel, M. Hempel, M. Härting, W. Bauer-Kugelmann, Werner Triftshäuser
Authors: Akihiko Kubo, Junichi Tamaki
Abstract: A solid-type diamond rotary dresser consisting of a CVD diamond disc is developed and applied to the dressing of a vitrified CBN grinding quill for internal grinding. This dresser has a feature not found in the other discrete-type rotary dressers used thus far, in which it continuously contacts the grinding wheel and leaves a spiral on the grinding wheel surface. The solid-type diamond rotary dresser was mounted on a low-speed spindle supported by journal bearings, and its dressing performance was compared with those of two discrete-type rotary diamond dressers: a dressing roll on which surface single diamond grains are brazed and a dressing roll made of a metal-bonded diamond wheel. It is found that the solid-type diamond rotary dresser tends to bring about rough grinding conditions among the three dressers.
Authors: Vladimir J. Trava-Airoldi, Evaldo Jose Corat, Vítor Baranauskas
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