No 2 (2019)

DOI https://doi.org/10.18799/24056537/2019/2/233

RESOURCE-EFFICIENT METHODS FOR PREDICTING AND SELECTING HEAT-RESISTANT ALLOYS

The power plant resource efficiency is largely dependent on heat-resistant alloys and is limited by the standard turbine operating temperature, which is slightly greater than 1000°C. These temperature limits are dependent on the characteristics of the heat-resistant alloys used in power plants. The current research aimed to discover new heat-resistant alloys using computer-based models to simulate the various properties of such materials. The first-principle methods were initially used in this study. These methods can determine the most important properties of alloys with a high degree of accuracy. This study presented an overview of the software used for first-principle simulation. Using RuAl as the demonstration alloy in this study, we provided step-by-step instructions on how to effectively study the properties of the heat-resistant alloys. Using the first-principle methods, the phonon spectrum and density of the phonon states of B2 RuAl were assessed. We use the parameters of the phonon spectrum to calculate the Grüneisen constant, volume coefficient of thermal expansion, Debye temperature, and temperature dependence of the heat capacity to estimate the melting temperature. Based on the RuAl alloy, the bulk moduli of the elasticity and equilibrium values of lattice parameters were calculated. The simulated results showed good agreement with the experimental data. The calculated parameters of RuAl were compared with those of the NiAl heat-resistant alloy. Using these results, we presented a method for selecting an alloy based on the replacement of ruthenium with nickel in the RuAl alloy. Selection was performed by analyzing the bulk modulus of elasticity and the electron structure of the Ru(Ni)Al alloy.

Keywords:

phonon spectrum, density of phonon states, parameters of cell, heat-resistant alloys, Grüneisen constant, thermal expansion, electron structure, resource-efficient technologies

Authors:

V.B. Evdokimov

A.A. Artamonov

E.V. Plotnikov

N.A. Konstantinova

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