Thermal Stress Analysis of Environmental Barrier Coatings Considering Interfacial Roughness

Abstract

A numerical analysis of the effect of roughness interface on the thermal stress in the environmental barrier coatings for ceramic matrix composites was performed. Based on the concept of representative volume elements, a micromechanical finite element model of the coated composites was established. The rough interfaces between the coating layers were described using sine curves. The cooling process after preparation and the typical service conditions for the CMCs component were simulated, respectively. The results show that the rough interface has little effect on the temperature distribution along the depth direction for the studied T/EBC coatings for SiC/SiC composites. The stress concentration occurs at the rough EBC/BC interface, which is prone to cause delamination cracking. Under typical service conditions, the high temperature can eliminate part of the thermal residual stress. Meanwhile, the thermal gradient will cause large thermal stress in the TBC layer and the stress will result in surface cracks. The stress concentrations appear at the peaks and valleys of rough interfaces. The variation range of thermal stress increases with the roughness amplitude and decreases with the wavelength.

Influence of Cr-Al-Si-N and DLC-Si Thin Coatings on Wear Resistance of Titanium Alloy Samples with Different Surface Conditions

“…This is confirmed by the empirical dependence of the stresses arising in the plane of adhesive contact under the external load, which can cause adhesive destruction of the coating. [84,85]. Because of the above, it is logical that the Cr-Al-Si-N/DLC-Si coating, which has the elastic modulus closest to titanium alloy and the best H/E ratio, demonstrated higher LC2 and LC3 loads, indicating adhesive destruction and delamination of the coating from the samples.…”

A Review on Ceramic Matrix Composites and Environmental Barrier Coatings for Aero-Engine: Material Development and Failure Analysis

“…Then, it is convenient to simulate the initiation and propagation of cracks by various methods integrated into the FE analysis, such as VCCT and XFEM. For instance, the author conducted a numerical study of the effect of the roughness interface on thermal stress in the EBCs [79]. A micromechanical RVE model of the coated composites was established and calculated using the FE method.…”

Nonporous, Strong, Stretchable, and Transparent Electrospun Aromatic Polyurea Nanocomposites as Potential Anticorrosion Coating Films

“…The casting and spray-coating methods used by the studies in Table 3 have potential downsides. For example, casted polymeric coatings could lead to uneven thickness, causing stress concentration and, therefore, crack formation [100]. Spray coating, on the other hand, deposits microdroplets, leading to the formation of pinhole defects [53]; therefore, it allows oxygen and chloride ions to attain the metal and consequently accelerate the corrosion process.…”