Tailorable shielded compliance of thermal barrier coatings through laser texturing and microstructural modification: microfeature design and validation

Thermal barrier coatings (TBCs) are widely used for protecting components from an aggressive environment and excessive temperatures. However, the top coat can lack thermal compliance and environmental resistance, promoting premature failure. This study provides an approach to design, produce, and evaluate the novel shielded-compliant TBCs to address these challenges. Top coat laser grooving can lower thermal mismatch levels and hinder crack propagation, whereas laser glazing can enhance strength and anti-corrosion performance. Material analysis for the glazed layer revealed large columnar grains alongside a stress-free structure compared to the as-sprayed coating. The digital image correlation (DIC) in-situ heating test showed vertical cracks after glazing already to be effective stress relief features, with the controlled grooves showing the most prominent compliance, as suggested by finite element analysis (FEA). Such a concept may be applied to any coating where increased thermal compliance or environmental protection is needed, making it a highly versatile tool.