VAPOR-PHASE DEPOSITION ON HIGH-TEMPERATURE SURFACES

Vapor phase deposition was studied at temperatures ranging from 500°C to 900°C. This study was carried out to determine the mechanism of deposition of tricresyl phosphate (TCP) from the vapor phase on chromium-nickel alloy, hot pressed silicon carbide, and hot pressed silicon nitride substrates under different atmospheres including an inert carrier gas and an inert gas plus oxygen. The deposited films were studied using scanning electron microscopy (SEM), optical microscopy, and an electrobalance to analyze the surface topography and calculate the deposition rate. From the data obtained using nickel-chromium alloy substrates, kinetic analysis were made using the Avrami equation from which the specific reaction rate constant (K), and the apparent activation energy (Ea) were determined. This analysis suggests that chemisorption is the rate controlling step. © 1990 Taylor & Francis Group, LLC.