Work

The aim of the scientific work is to establish the regularity of formation of structure and phase composition in the zone of joints of dissimilar Ni-based superalloys obtained by butt-welding and to determine their influence on the mechanical properties of joints. The urgency of scientific work is due to the fact that in the development of new designs of aircraft gas turbine engines (GTE) domestic manufacturers (SE "Ivchenko-Progress", JSC "Motor Sich") provide for the replacement of mechanical fasteners with welded joints, which will reduce weight engine. This task is especially relevant for nodes such as "blade-disk", the elements of which are made of dissimilar Ni alloys: disks - from deformed medium-alloy alloys with a content of γ'-phase 20… 35%, blades - from cast high-alloy alloys containing reinforcing γ'- phases 57… 65%. To achieve the purpose of scientific work it is necessary to solve the following tasks: - to investigate the processes of heating and deformation during resistance butt-welding of dissimilar Ni-based superalloys; - to investigate the microstructure of the metal and the change in the concentration of alloying elements in the area of the joints of the disc and blade Ni superalloys; - to investigate the influence of the thermodeformation cycle of resistance butt-welding on the morphology of the strengthening phases (γ'-phase and carbides) in the weld zone; - to establish the connection of indicators of mechanical properties with the microstructure and morphology of strengthening phases in compounds of dissimilar Ni alloys. The obtained results will be the basis for the development of technologies of resistance butt-welding of dissimilar Ni-based superalloys in relation to the manufacture of units of the type "blade-disk" of aviation gas turbine engines.