Abstract:
A coherent material is formed on a substrate ( 10 ) by providing a precursor suspension ( 14 ) in which particulates are suspended in a carrier fluid, and directing the precursor suspension ( 14 ) at the substrate ( 10 ) from a first source ( 12 ). Generally contemporaneously with application of the deposited precursor suspension ( 14 ) to the surface, hot gases, e.g. hot gases produced by a flame ( 16 ), are directed at the substrate ( 10 ) from a remote second source ( 18 ) to fuse the particulates into the coherent material.
Abstract:
An improved chemical vapor deposition apparatus and procedure is disclosed. The technique provides improved shielding of the reaction and deposition zones (26, 28) involved in providing CVD coatings by establishing a barrier zone (30) wherein gases flowing from a reaction zone (26) and deposition zone (28) to the ambient atmosphere are made to flow at a velocity of at least 15.24 m/min. Coatings can thus be produced, at atmospheric pressure, of materials which are sensitive to components in the atmosphere on substrates which are sensitive to high temperatures and which are too large, or inconvenient, to process in vacuum or similar chambers. The improved technique can be used with various energy sources and is particularly compatible with Combustion Chemical Vapor Deposition (CCVD) techniques.