ON THE BEHAVIOR OF THERMO ACOUSTIC PARAMETERS IN THERMAL BARRIER COATING MATERIALS

Abstract

The thermo acoustic parameters of Thermal Barrier Coating Materials are estimated in terms of the thermal expansion coefficient (α) at 1273 K on the assumption that the Moelwyn-Hughes parameter (C1) is the dominant factor. The Moelwyn-Hughes parameter has been employed in various established relations and evaluated lattice Gruneisen parameter (Γ), non-linear Beyer’s parameter (B/A), the free available volume (Va/V), the repulsive exponent of intermolecular potential (n), the reduced molar volume ( ), the reduced compressibility (β), isochoric acoustical parameter (), the Anderson-Gruneisen parameter (δ), the Sharma’s parameter(S0) and other parameters. The relationship between the Γith , Γich , and Γiba has been studied and the magnitudes are interpreted in terms of the characteristic behavior of material. The parameter Y is found to be close to 0.10 which may infer that the normal modes of vibrations contributing to heat capacities are almost negligible. Sharma’s parameter has been found to be constant i.e., 1.10. The present study gives an opportunity to understand the significance of fractional free volume and the S0 parameter in describing the anharmonic and non-linear properties of these materials.