ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The morphological features of silicon carbide coatings, deposited on graphite from SiCl4, C3H8 and H2 mixtures, were investigated. Based on preliminary thermodynamic calculations, the experiments were performed at atmospheric pressure in a cold-wall reactor by varying the deposition temperatureT D in the 1473–1673 K range, and varying the deposition time between 10 and 120 min. Scanning electron microscopy examinations showed considerable differences in surface morphology depending on the process parameters. A transition from a nodular to a faceted structure was observed by moving towards higherT D values. A double-layer structure was detected on the thickest coatings due to a sharp columnar-microcrystalline transition. The coatings prepared atT D=1673 K showed surface microhardness values as high as 4000 HK and an optimum capability to protect graphite substrates against oxidation at 1273 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01113883
