Microstructure and microhardness of nickel-base heat-resistant alloys obtained by directional and equilibrium crystallization

Received: August 22, 2019
Revised: September 28, 2019
Accepted: December 28, 2019
1
Lviv Polytechnic National University
2
Lviv Polytechnic National University
3
Lviv Polytechnic National University
4
Lviv Polytechnic National University
5
Karpenko Physico-mechanical Institute of the NAS of Ukraine
6
Karpenko Physico-mechanical Institute of the NAS of Ukraine

In order to determine the safe operational life of the components of gas turbine engines (GTE), introductory tests of nickel-base heat-resistant alloys (NHRA) have been performed. X-ray fluorescence and X-ray diffraction analyzes, optical microscopy and Vickers hardness measurements provided data on the phase-structural state and mechanical properties of the pristine ZhS6K-VI and ZhS32-VI alloys obtained by equilibrium and high-speed directional crystallization, respectively. Almost complete compliance of the investigated materials with the certified alloys in chemical and phase composition has been found. A significant difference in the parameters of the fragments of the microstructure of the investigated alloys, which is naturally consistent with the conditions of equilibrium and high-speed directional crystallizations, was revealed. A slightly lower anisotropy of microhardness (2.8 %), measured in transverse and longitudinal sections, was found in the ZhS6K-VI alloy as compared to the anisotropy (5.1 %) in the ZhS32-VI alloy. The obtained results will be used to test a non-destructive method for determining the safe operational life of gas turbine engine components.

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A. Trostianchyn, S. Shvachko, V. Kulyk, E. Pleshakov, Y. Molkov, T. Lenkovskiy, "Microstructure and microhardness of nickel-base heat-resistant alloys obtained by directional and equilibrium crystallization", Ukrainian Journal of Mechanical Engineering and Materials Science, vol. 5, no. 3-4, pp. 33-38, 2019.