Numerical study on interaction of surface cracking and interfacial delamination in thermal barrier coatings under tension
88
Citation
47
Reference
10
Related Paper
Citation Trend
Keywords:
Delamination
This chapter contains sections titled: The equivalence of the force and energy description of surface tension and surface energy Derivation of the Laplace pressure equation Methods for determining the surface tension of liquids Capillary rise and the free energy analysis The Kelvin equation The surface energy and cohesion of solids The contact angle Industrial Report: Photographic-quality printing Sample problems Experiment 2.1: Rod in free surface (RIFS) method for the measurement of the surface tension of liquids Experiment 2.2 Contact angle measurements
Capillary surface
Laplace pressure
Specific surface energy
Kelvin equation
Capillary length
Capillary pressure
Free surface
Cite
Citations (1)
This paper analyzes the surface tension and specific surface free energy of liquid and discusses their microstructure mechanism. The analysis indicates that surface tension of liquid is related to the liquid surface problem in terms of force and surface free energy is connected with the liquid surface problems regarding energy. At the molecular level,the surface tension involves macroscopic conduction of the molecular interactive force. The surface tension results from the liquid surface hole and the specific free energy is attributed to the work of molecular interaction force. So both of them have something to do with the molecular interaction force.
Free surface
Specific surface energy
Tension (geology)
Cite
Citations (3)
Delamination
Thermal effusivity
Thermography
Cite
Citations (14)
A unitary approach has been proposed for the calculation of surface energy and surface tension of nanoparticle being in equilibrium with its saturated vapor on both flat and curved surfaces at given temperature. The final equations involve parameters dependent on the type of premelting structure: bcc, fcc or hcp.
Premelting
Specific surface energy
Tension (geology)
Cite
Citations (8)
To integrate surface and interfacial properties and phenomena into the Hansen solubility parameter (HSP) framework, we propose an equation for estimating both surface tension/energy for liquids and solids as well as interfacial tension/energy. The contact angles of probe liquids on various polymers estimated using the proposed equation based on bulk HSPs (derived from bulk properties such as solubility or swelling, and not on surface properties) are compared with those measured using the sessile drop method. It is found that their correlations are sufficient for predicting wettability in practical use. All the respective tension and energy correlations are reasonably good, confirming the predictive power of the proposed equation for all values of liquid surface tension, solid surface energy, and interfacial tension. The unification of surface and interfacial properties and phenomena with HSPs (derived from bulk properties) enables us to estimate the surface properties from bulk properties and vice versa. The huge database of HSPs is now applicable to not only bulk phenomena but also surface and interfacial phenomena. Furthermore, complex processes or systems composed of multiple constituents and phases can be understood and designed using the modified HSP framework.
Hildebrand solubility parameter
Cite
Citations (16)
Tension (geology)
Crystal (programming language)
Specific surface energy
Cite
Citations (26)
View Video Presentation: https://doi.org/10.2514/6.2021-0432.vid Thermal Barrier Coatings (TBCs) protect and insulate the superalloy parts in hot sections of gas turbine engines and are used to achieve higher turbine inlet temperatures, resulting in an increase in engine efficiency and consequently a lowering of NOx emissions and fuel consumption. Such performance is only possible if the integrity of the TBC under aggressive thermo-mechanical environments is ensured. Delamination is common but characterization methods to assess the severity of the damage are lacking. In this work, a Kubelka-Munk model was constructed to quantify numerically the luminescence contrast between intact and delaminated coating areas. This method relies on the drastic change in reflectivity at the interface between the top coat and the bond coat when a delamination forms. Two distinct TBC configurations containing an erbium-doped yttria-stabilized zirconia (YSZ:Er) layer for delamination sensing were used to validate this model. An artificially-induced delamination was successfully tracked on each sample configuration by measuring the luminescence contrast at different emission lines of erbium at around 545, 562, 655 and 680 nm to further validate modeling predictions as well as to evaluate the effect of wavelength-dependent scattering of the TBC with delamination detection capabilities. Luminescence-based methods for delamination detection combined with quantification models can provide accurate diagnosis with potential for the enhanced monitoring of high-temperature coatings throughout their lifetime.
Delamination
Physical vapor deposition
Cite
Citations (0)
The applicability of the surface energy analysis method to the detergency system is discussed. This method involves multicomponent washing liquids, such as binary mixtures of organic liquids and aqueous solutions of surfactants. The surface tension and its components of these mixtures and surfactant solutions, which were calculated from contact angle measurements, were not linearly proportional to the molar ratio or concentration. Oily dirt/washing liquid interfacial tensions were estimated from surface tension components. The interfacial tension tended to be overestimated compared with that observed in the systems using surface active materials. The results of a rolling-up test of oil drops suggest a correlation between the work of adhesion and washability.
Cite
Citations (6)
Surface tension is a crucial factor in the crystallization of organic semiconductors from solutions. However, the current conclusions based on experimental results have been primarily empirical and qualitative, making it hard to distinguish the role of surface tension from other solvent properties. In this study, we employed both molecular dynamics simulations and experiments to investigate crystal nuclei behavior at the liquid-air interface. Through equilibrium simulations and free energy calculations, we quantitatively described the moving behavior of nuclei in various solvents, relating it to an interfacial transition, in terms of interfacial tension. Nuclei tend to remain at the liquid-air interface if the surface tension of solvents is higher than the surface free energy of nuclei but sink into the bulk liquid otherwise. Furthermore, aside from governing the nuclei behavior, surface tension also determines the crystallization location, as confirmed through growing crystals on substrates with Ag nanowires as impediments. By clarifying the role of surface tension, our research contributes to the knowledge of solution crystallization of organic semiconductors and the establishment of a framework for tuning processing conditions and crystal morphology for future studies.
Crystal (programming language)
Cite
Citations (1)
Specific surface energy
Free surface
London dispersion force
Cite
Citations (38)