Abhijith Vijay, V.Santhy, K.Govindarajan, G.Rajasekaran, B.2026-02-042023Surface and Coatings Technology, 2023, 452, , pp. -2578972https://doi.org/10.1016/j.surfcoat.2022.129132https://idr.nitk.ac.in/handle/123456789/22064The paper focuses on in-situ high-temperature X-ray diffraction (HT-XRD) study on atmospheric plasma sprayed NiCrAlY coating. The sample was in-situ heated from 25 °C to 1150 °C in a controlled atmosphere (3 × 10−4 bar), and the corresponding X-ray diffraction patterns for different temperatures were recorded. The effect of temperature on crystallite size, lattice strain, and coefficient of linear thermal expansion was studied. Major phases identified are γ-Ni, γ’-Ni<inf>3</inf>Al, β-NiAl, and α-Cr. The formation of stable α-Al<inf>2</inf>O<inf>3</inf> and spinel was found above 1000 °C. The transformation of β to γ’ and γ phase was observed as a function of temperature. The equilibrium phases and the thermal expansion of disordered Face Centered Cubic (FCC) and Body Centered Cubic (BCC) phases were predicted and supported by Thermo-Calc prediction for the stable temperature range. Results showed that the non-equilibrium microstructure produced by thermal spray process did not alter the thermal expansion behaviour. In-situ treatment resulted in microstructure and elemental homogenization. The thermal expansion and mechanism of phase evolution were discussed. © 2022 Elsevier B.V.AluminaAluminum alloysAluminum oxideAtmospheric temperatureChromium alloysCobalt alloysCrystallite sizeMicrostructureNickel compoundsPlasma jetsPlasma sprayingTernary alloysX ray diffractionAtmospheric plasma sprayAtmospheric plasmasHigh-temperature X-ray diffractionHigh-temperature XRDIn-situ high temperature XRDLattice strainMicrostructure evolutionsNiCrAlY bond coatsPlasma-sprayedThermocalcThermal expansion