Diamond deposition on cemented carbide by chemical vapour deposition using a tantalum filament

Matsubara, Hideaki; Sakuma, Taketo

doi:10.1007/bf00581110

Cited by 42 publications

(10 citation statements)

References 11 publications

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“…Therefore, using an average z cd Z 1000 1200 1400 1600 Raman shift (cm -' ) pressure coefficient of 2.5 cm -' GPa ', it is possible to estimate a 2 GPa residual compressive stress in the deposited diamond originating from the different thermal expansion coefficients of diamond and cemented tungsten carbide. This value is in good agreement with the residual thermal stress (crtherma) which can be calculated according to the following relationship [1] where adia = 3.15 X 10-6 K-' is the average thermal expansion coefficient of diamond in the 130 to 930°C temperature range, aub = 5.5 x 10 -6 K -' is the average thermal expansion coefficient of ISO-grade K10 cemented carbide in the 20 to 800°C temperature range, AT is the difference between substrate temperature during CVD and room temperature, Edi,, is the Young's modulus of diamond (1 TPa), and v is the Poisson ratio of the film (0.07). By using Eq.…”

Section: Resultssupporting

confidence: 80%

A Raman Study of Diamond Film Growth on Co‐Cemented Tungsten Carbide

Polini

Traversa

Marucci

et al. 1997

J. Electrochem. Soc.

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Phase purity and crystallinity of diamond films grown by hot filament chemical vapor deposition on ISO-grade K10 cemented carbide [94.2 weight percent (w/o) WC-5.8 w/o Co] were studied by Raman spectroscopy as a function of substrate temperature, gas phase composition, and substrate pretreatments. High-quality diamond films were grown using 0.5% CH4/H2 in a rather narrow range of substrate temperatures (750 to 760°C). In all the deposited coatings, the firstorder Raman band of diamond is detected at 1337 cm . This fact indicates that a 2 GPa residual compressive stress is present in the diamond phase. The linewidth of the diamond Raman peak increases with deposition temperature. This effect has been ascribed to a higher density of defects in diamond crystallites. It has been observed that Co removal from the substrate surface by wet chemical etching before deposition is less effective than a careful selection of deposition parameters to reduce the codeposition of nondiamond carbon phases. This finding has been attributed to the fast diffusion of the binder from the bulk to the substrate surface, even for the etched substrates. IntroductionThe chemical vapor deposition (CVD) of diamond films on cemented carbides allows the development of cutting tools with improved cutting performance and durability.'7

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Section: Resultssupporting

confidence: 80%

A Raman Study of Diamond Film Growth on Co‐Cemented Tungsten Carbide

Polini

Traversa

Marucci

et al. 1997

J. Electrochem. Soc.

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“…The W found in the top layer in this RBS measurement originates from the filaments, possibly due to high base pressure and/or the aggressive nature of the atomic hydrogen during the anneal and CNT deposition. Heated W wires are known to carburize during CVD processes and form WC and W 2 C phases [24][25][26][27], to determine how and in what form in our CVD process this W or WC x is deposited in the top layer additional experiments are needed.…”

Section: Resultsmentioning

confidence: 99%

Formation of isolated carbon nanofibers with hot-wire CVD using nanosphere lithography as catalyst patterning technique

Houweling¹,

Verlaan²,

Grotenhuis³

et al. 2009

Thin Solid Films

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a b s t r a c t a r t i c l e i n f o Available online xxxx Keywords:Hot-wire CVD Carbon nanotubes Nanosphere lithographyRecently the site-density control of carbon nanotubes (CNTs) has attracted much attention as this has become critical for its many applications. To obtain an ordered array of catalyst nanoparticles with good monodispersity nanosphere lithography (NSL) is used. These nanoparticles are tested as catalyst sites in hotwire chemical vapor deposition (HWCVD) of carbon nanostructures. Aside from using NSL also nickel (Ni) nano-islands are made by thermal annealing of a thin Ni film and tested as catalyst sites. Multiwall CNTs, isolated carbon nanofibres, and other nanostructures have been deposited using HWCVD. Tungsten filaments held at~2000°C are used to decompose a mixture of ammonia, methane and hydrogen. The structures have been characterized with Scanning Electron Microscopy, High Resolution Transmission Electron Microscopy, Raman spectroscopy and Rutherford Backscattering Spectroscopy.Crown

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“…1a shows the XRD pattern of a typical carbonized Ta catalyst, and only TaC (JCPSD Card No. 65-8795) peaks are observed, which indicates the TaC surface layer is thick enough to cover the whole wire [20,32]. The catalyst exhibits a yellow color corresponding to TaC, as presented in the inset.…”

Section: Characterization Of Si Films and Catalystsmentioning

confidence: 94%

“…EDX analysis confirms the catalyst core is pure Ta (not shown here). The shell layer has a uniform thickness of about 22 μm, which is suggested to be composed of TaC and Ta 2 C annularly [32][33][34], and the Ta 2 C is not identified by the direct XRD characterization for its existence in the inner side of the carbide layer. Fig.…”

Section: Characterization Of Si Films and Catalystsmentioning

confidence: 99%