Restoration of internal surfaces of cylindrical parts of small diameters by cold gas dynamic spraying

Abstract

Wear of internal surfaces of cylindrical parts of small diameters is a common defect of equipment used in the agro-industrial complex. There are problems with low powder utilization and lack of a design solution for coating the inner surfaces of cylindrical parts with small diameters. (Research purpose) The research purpose is in evaluating the adhesive and cohesive strength and developing a technology for restoring the internal surfaces of cylindrical parts of small diameters by cold gas-dynamic spraying. (Materials and methods) Authors applied the method of cold gas dynamic spraying. The article presents a device for gas-dynamic coating on the inner surfaces of cylindrical parts and determines the optimal deposition modes for powder consumption and heating temperature. A portable DIMET-403 unit, aluminum oxide powder for surface preparation, a-20-11 aluminum powder, and a steel plate were used for the study. The weight was measured on analytical scales with an accuracy of 0.001 grams. Tests were performed on the adhesive and cohesive strength of the coating on cylindrical samples prepared by mechanical processing, under the most favorable conditions with a duration of deposition equal to 60 seconds. Samples were processed after sputtering on a lathe to obtain a cylindrical belt. (Results and discussion) The values of adhesive and cohesive strength of coatings fit into the range of values suitable for operation, and meet the conditions for obtaining a wear-resistant ceramic coating. The article presents a technology for obtaining a sublayer for the manufacture of ceramic wear-resistant surfaces in a pair of friction piston ring-cylinder. (Conclusions) The developed restoration technology of internal surfaces of cylindrical parts of small diameters by cold gas-dynamic spraying solved the problem of their wear.