STRUCTURAL INHOMOGENEITIES IN PYROCARBON COATINGS DEPOSITED IN THE FLUIDIZED BED

摘要

An appreciable inhomogeneity in the structure of a 100 µ thick flat pyrocarbon coating deposited in a fluidized bed at constant temperature and gas composition has been found as a function of the thickness.nIt turns out that the preferred orientation and the crystallite size increase continuously with the coating thickness, while the interlayer spacing decreases.nEmphasis is placed on measurements of the preferred orientation at various coating levels and on the precise X-ray technique and sample preparation necessary to achieve a reliable and reproducible measurement of this quantity.