NICKEL-BASED SUPERALLOYS EXPLOITATIONAL PROPERTIES RISING DUE TO THE INFLUENCE ON LATTICE PARAMETERS

Abstract

Objective. It consists in establishing relationships between the chemical composition, mechanical properties, and dimensional inconsistency of crystal lattices of nickel-based superalloys. That makes it possible to reduce the volume of experimental research in the conditions of the production process and experimental developments. Research methods. The results of experimental and calculated data, formed on the basis of experimental and results taken from open sources, are given. The phase composition was determined by X-ray structural analysis using the Bragg-Brentano focusing method on a RIGAKU MINIFLEX 600 diffractometer (CoKα radiation). The experimental values were processed by the method of least squares with obtaining correlation dependencies of the “parameter-property” type and establishing mathematical equations of regression models that optimally describe these dependencies. Obtained results. It was established that with an increase in the amount of misalignment of crystal lattices, the strength of alloys decreases due to significant internal stresses. It was found that for alloys of uniform and directional crystallization, the extremum is observed at a value of 1.5...1.6 Kγ′, this is due to a decrease in the number of elements in the γ-solid solution. It is shown that the obtained dependences correspond to reality and coincide with experimental data at the level of 10 %. Scientific novelty. The value of the work lies in the fact that the dependence of the influence of alloying elements on the mechanical properties and the discrepancy in the sizes of the crystal lattices was obtained, which made it possible to determine the properties without conducting experiments. It was established that changes in the course of dependencies are closely correlated with the processes taking place in the structure of alloys. Practical value. The obtained dependencies can be used both for the development of new superalloys and for the improvement of the compositions of industrial alloys.