Study on Forming Mechanism of the Fe-Al2O3-FeAl2O4 Composite Coating by Reractive Plasma Spraying
|School||Hebei University of Technology|
|Keywords||Spray granulation Reactive plasma spraying Composite coating Reaction Mechanism Quenching method|
This selection of industrial aluminum powder and iron oxide powder as raw material, suitable for plasma spraying of composite powder prepared by spray granulation and by plasma spraying technique Composite Powder into a metal-ceramic composite coating . To prepare a composite coating microstructure morphology and phase composition of the observation and analysis, combined with the quenching method and the thermodynamic analysis, analysis of the obtained data , and to study the mechanism of the formation of the whole reaction . Ratio, the optional industrial aluminum powder and iron oxide powder in accordance with certain reaction ratio by dry mixing , wet mixing methods such as the powder is mixed uniformly , and adding a binder to improve the binding strength of the powder prepared as a slurry , and finally by the granulation prepared by the composite powders . After screening , the composite powder of uniform size and shape of the rules , suitable for spraying . Stream to prepare a composite powder is fed into the plasma flame , powder heated self - propagating reaction occurs , the product by means of the speed of the plasma gas is deposited on the substrate surface and stacked on top of each other to form a composite coating . Composite coating that FeAl2O4 major organizations , and uniform distribution of Fe and A1203 particles . Quenching test composite powders , different flight distance under the organization of the composite powders coating , coated tissue components by means of XRD analysis ; composite powders by differential thermal analysis , organizational change in the heating process and reaction conditions; by Spray-Watch2i observations composite powders speed variation of the temperature during the flight ; data obtained by the above combination of thermodynamic analysis, to determine the reaction of the composite powder in the flame stream includes three stages . Each stage of the reaction will release a lot of heat , but the reaction the intensity gradually reduce eventually stabilize . Deduce the chemical reactions that occur in each stage and to determine the reaction mechanism , it is clear to obtain a metal-ceramic composite coating formation process .