CREATION OF COMPOSITE ELECTRICALLY CONDUCTIVE COATINGS BY GAS DYNAMIC SPRAYING

Abstract

The article presents the results of research of spraying processes of composite electrically conductive coatings using copper C01-11 and aluminum A20-11 powders in order to determine the effect of components on each other in the formation of cold gas-dynamic spraying (CGDS) and the development of recommendations for the introduction of additional component to obtain a composite coating with a given ratio of different components. For example, when at a working air temperature of 300 ° C the copper sputtering coefficient is almost zero, it is a search for the experimental dependence of the sputtering coefficient change depending on the percentage of components of copper and aluminum powders in the sprayed mixture and determination of their residual content in the coating. based on the obtained data of the sputtering coefficients of copper and aluminum. The CGDS method obtained blanks with composite coatings from mixtures of powders of aluminum A20-11 and copper C01-11 at different initial concentrations of aluminum by weight (from 0 to 100% with a step of 10%) under otherwise equal conditions (air pressure 0,6 MPa, temperature air heating 300 ° C). The sputtering coefficient of a mixture of copper and aluminum and the residual content of components in the sprayed composite coatings were found. Data on the residual content of the individual components in the sprayed coating allows to determine the composition of the source powder required for spraying a given content of each of the components in the coating. The dependences of the spraying coefficients of copper C01-11 and aluminum A20-11 on the mass content of aluminum in the sprayed mixture were found. When the initial concentration of aluminum is less than 66%, the coefficient of copper deposition is greater than the coefficient of deposition of aluminum. Both increase with increasing concentration of aluminum until it reaches 61%. At high concentrations of aluminum (more than 66%) the spray coefficients of copper, aluminum and their mixtures coincide. The results obtained on the residual content of the components in the coating allow you to select the composition of the source powder required to obtain the desired content of components in the coating. For example, the maximum residual copper content (~ 95%) can be obtained by adding 30-40% aluminum to the starting powder. The obtained results prove the influence of the components on each other and justify the amount of introduction of an additional component for spraying a composite coating containing a component that is difficult to spray.