Growth of diamond film by CVD on near net shape fabricated {beta}-SiC/TiC composites synthesized using SHS

Conference · Sun Oct 01 00:00:00 EDT 1995

OSTI ID:100588

Raghunathan, R; Chowdhury, R; Jagannadham, K; Narayan, J ^[1]

---

1. North Carolina State Univ., Raleigh, NC (United States). Dept. of Material Science and Engineering

{beta}-SiC/TiC composites were synthesized using the process of self propagating-high temperature combustion synthesis (SHS). The heat released during the exothermic reaction between Si and C powders (with a {Delta}H of {minus}14 kcal/mol) and that Ti and C powders (with a {Delta}H of {minus}44.1 kcal/mole) is sufficient to cause the melting of the powders into which the carbon diffuses and from which {beta}-SiC and TiC precipitate out of the supersaturated solution. The composite was characterized using X-ray diffraction techniques, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. An attempt was made to understand the mechanism of formation of the composite. The authors have proposed a mechanism to understand the formation of the SHS compounds based on dissolution, diffusion and precipitation from the supersaturated solution. There is no evidence for the presence of TiSi{sub 2} and an attempt was made to explain this observation based on three energy considerations. Diamond film was then grown on the pellet by hot filament CVD technique using methane and hydrogen gas as the reactants. The deposition was conducted for a period of four hours. A continuous film of diamond was found to grow on {beta}-SiC/TiC composite using this technique. The diamond film was characterized by using Raman spectroscopy and SEM. The diamond film showed both (001) and (111) facets with average grain size of 5 {micro}m.

• OSTI ID: 100588
• Report Number(s): CONF-941144-; ISBN 1-55899-266-9; TRN: IM9540%%59
• Resource Relation: Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 28 Nov - 9 Dec 1994; Other Information: PBD: 1995; Related Information: Is Part Of Ceramic matrix composites -- Advanced high-temperature structural materials; Lowden, R.A.; Ferber, M.K. [eds.] [Oak Ridge National Lab., Oak Ridge, TN (United States)]; Hellmann, J.R. [ed.] [Pennsylvania State Univ., University Park, PA (United States). Center for Advanced Materials]; Chawla, K.K. [ed.] [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)]; DiPietro, S.G. [ed.] [Textron Specialty Materials, Lowell, MA (United States)]; PB: 493 p.; Materials Research Society symposium proceedings, Volume 365
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
SYNTHESIS
MICROSTRUCTURE
SILICON CARBIDES
TITANIUM CARBIDES
DIAMONDS
CHEMICAL VAPOR DEPOSITION
COMBUSTION
CHEMICAL REACTIONS
DIFFUSION
PRECIPITATION
METHANE
HYDROGEN
RAMAN SPECTROSCOPY
SCANNING ELECTRON MICROSCOPY
GRAIN SIZE
X-RAY DIFFRACTION
TRANSMISSION ELECTRON MICROSCOPY