RESEARCH OF THE MICROSTRUCTURE OF COMPACT SAMPLES FROM ECONOMICAL HEAT-RESISTANT NICKEL ALLOY OBTAINED BY DIRECTED CRYSTALLIZATION IN THE PROCESS OF SELECTIVE LASER MELTING

Nickel-based alloys have found widespread use as heat-resistant alloys in the manufacture of gas turbine engines, mainly in the form of working blades and nozzles and, to a lesser extent, as turbine disks and rings. Their development is associated with an increase in the volumetric content of the γ′-phase, which leads to an increase in heat resistance due to the introduction of new alloying elements, such as, for example, rhenium (Re) and ruthenium (Ru). It is known that these alloying elements significantly influence the increase in the cost of the final product; for this reason, the development of economical alloys primarily without Re and Ru is currently relevant. In addition, research is relevant in the field of manufacturing parts using additive manufacturing (AM), which has its own advantages. This paper examines the possibility of producing compact samples with a directional structure by economical alloying using selective laser melting (SLM). Samples were studied and the relationship of alloying elements with the isolation of TCP phases, carbides and the percentage of mismatch between the lattice periods of the γ- and γ′-phases (misfit) with strength characteristics was established and analyzed. During the study, we obtained economically alloyed samples with more misfit than in second-generation rhenium alloys and determined the directions for further work.