MODEL RESEARCH ON SYNTHESIS OF Al2O3-C LAYERS BY MOCVD BADANIA MODELOWE NAD SYNTEZĄ WARSTW Al2O3-C METODĄ MOCVD

These are model studies whose aim is to obtain information that would allow development of new technology for synthesizing monolayers of Al2O3-C with adjusted microstructure on cemented carbides. The Al2O3-C layer will constitute an intermediate layer on which the outer layer of Al2O3 without carbon is synthesized. The purpose of the intermediate layer is to block the cobalt diffusion to the synthesized outer layer of Al2O3 and to stop the diffusion of air oxygen to the substrate during the synthesis of the outer layer. This layer should be thin, continuous, dense and uniform in thickness. Al2O3-C layers were synthesized from aluminum acetylacetonate by the CVD method on quartz glass heated in an induction furnace in the temperature range 800-1000◦C using argon as a carrier for the reactants. The layers were prepared also at low temperatures and were then subjected to crystallization at higher temperatures. The resulting layers prepared at temperatures above 900◦C were nanocrystalline (including the α-Al2O3 phase). Due to the fact that crystallization can be controlled, we may have a greater influence on the structure and thus the properties of the layer compared to direct synthesis at high temperature.