Molten‐Volcanic‐Ash‐Phobic Thermal Barrier Coating based on Biomimetic Structure

Abstract

AbstractVolcanic ash is a major threat to aviation safety. The softening/melting temperatures of volcanic ash lie far below typical aero‐engine operating temperatures. Thus, molten ash can accelerate the failure of thermal barrier coatings (TBCs). Here, inspired by natural superhydrophobic surfaces (e.g., the lotus leaf), a molten‐volcanic‐ash‐phobic TBC, which provides a large possibility to eliminate molten ash issues of TBCs, is developed. A hierarchically structured surface is first prepared on a (Gd0.9Yb0.1)2Zr2O7 (GYbZ) pellet by ultrafast laser direct writing technology, aiming to confirm the feasibility of the biomimetic microstructure to repel molten volcanic ash wetting. Then biomimetic‐structured GYbZ TBCs are successfully fabricated using plasma spray physical vapor deposition, which reveals “silicate” phobicity at high temperatures. The exciting molten‐volcanic‐ash‐phobic attribute of the designed surfaces is attributed to the lotus‐leaf‐like dual‐scale microstructure, emulating in particular the existence of nanoparticles. These findings may be an important step toward the development of next‐generation aviation engines with greatly reduced vulnerability to environmental siliceous debris.