ANALYSIS OF THE INFLUENCE OF CHANGES IN LASER RADIATION PARAMETERS ON STRUCTURE FORMATION DURING LASER CLADDING ON A THIN-WALLED BASE

During manufacturing of various structures and parts of products in the aerospace, aviation, chemical, engineering and other industries, a task of cladding of functional elements intended to perform a different set of certain critical tasks on thin-walled parts with a rigid structure is required to be performed in such a way as to prevent melting of the thin-walled base during material deposition.The purpose of this study is to establish the principles of influence of the parameters of the laser cladding process of metal on the structural formation of deposited layers applied to thinwalled body and functional parts of critical structures.The scientific results obtained in the course of the research are planned to be used in the development of laser cladding technologies for products in various industries.In order to study this problem, a number of experimental works were carried out, including the manufacture of a series of experimental cladding samples, analysis of their structure using optical microscopy, and measurement of their microhardness.The data obtained from the experiment was used to analyse the influence of laser metal cladding process parameters on the structure formation of deposited layers applied to thin-walled body and functional parts of critical structures.As a result of the study, it was determined that laser cladding of high-alloy corrosion-resistant steel powder produces a cast, dispersed structure of the deposited layers characteristic to the multilayer cladding process, consisting of an austenitic matrix and minor allocations along the boundaries of crystallites.It was found that when depositing the first layers of powder material on thin-walled steel, it is important to maintain a level of heat input of 45...50 J/mm, with a further increase of this value to 60 J/mm at a height of the deposited element of 2.75-3 mm.Further increase of the processing energy up to 75 J/mm when surfacing elements of greater height is undesirable due to the increase in the remelting zone of the deposited layers, as well as the appearance of under-melted metal powder particles of up to 20 m in size.