Nucleation and growth of diamond films on Ni-cemented tungsten carbide: Effects of substrate pretreatments

Journal Article · Mon Aug 01 00:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb07095.x· OSTI ID:6932633

Polini, R; Traversa, E ^[1]; Marcheselli, G ^[2]

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1. Univ. di Roma (Italy). Dipt. di Scienze e Tecnologie Chimiche
2. Fabbrica Italiana Leghe Metalliche Sinterizzate, Novara (Italy)

The nucleation and growth of diamond films on Ni-cemented carbide is investigated. Substrates made of WC with 6 wt% of Ni were submitted to grinding, and then to different pretreatments (scratching, etching, and/or decarburization) before diamond deposition. Diamond synthesis was carried out by hot-filament chemical vapor deposition (HFCVD) using a mixture of CH[sub 4] (1% v/v) and H[sub 2]. Depositions were performed for different lengths of time with the substrates at various temperatures. The specimens were analyzed before and after deposition by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffractometry (XRD). Raman spectra showed that the phase purity of the diamond films was not affected by the presence of nickel on the substrate surface. After wet etching pretreatments, the nucleation of diamond was enhanced, mainly at the WC grain boundaries. Continuous films were obtained on scratched and etched substrates. The decarburizing treatment led to the formation of metallic tungsten and of brittle nickel-tungsten carbide phases. These phases reacted in the early stages of diamond film formation with gaseous carbon species with a parallel process which competes with stable diamond nucleus formation. The diamond film formed after long-term deposition on these samples was not continuous.

• OSTI ID: 6932633
• Journal Information: Journal of the American Ceramic Society; (United States), Vol. 77:8; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DIAMONDS
CHEMICAL VAPOR DEPOSITION
SUBSTRATES
SURFACE TREATMENTS
TUNGSTEN CARBIDES
CUTTING TOOLS
EXPERIMENTAL DATA
METHANE
NICKEL
ALKANES
CARBIDES
CARBON
CARBON COMPOUNDS
CHEMICAL COATING
DATA
DEPOSITION
ELEMENTAL MINERALS
ELEMENTS
HYDROCARBONS
INFORMATION
METALS
MINERALS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
REFRACTORY METAL COMPOUNDS
SURFACE COATING
TOOLS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TUNGSTEN COMPOUNDS
360601* - Other Materials- Preparation & Manufacture