Turbomachinery Blade Thermomechanical Interface Science and Sandphobic Coatings Research

Gas turbine engines operating in hostile environment polluted with micron-sized solid particles are susceptible to blade surface damage. Commercial/Military fixed-wing aircraft engines and helicopter engines often have to operate over sandy terrains or in volcanic areas; on the other hand gas turbines in marine applications are subjected to salt spray, while the coal-burning industrial power generation turbines are subjected to fly-ash. The presence of solid particles in the working fluid medium has an adverse effect on these engines, both structurally and aerodynamically. Typical turbine blade damages include blade wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration. The focus of this research work is to simulate a single solid particle impact on typical turbomachinery material targets using non-linear dynamics analysis. The objective of this research is to understand the interfacial kinetic behaviors that can provide insights into the physics of particle interactions and to enable leap ahead technologies in material choices and sand-phobic thermal barrier coatings for turbomachinery blades. This paper outlines the research efforts at the U.S Army Research Laboratory (ARL) to come up with novel gas turbine engine protective coatings, and analysis methods to study particle impact effects at the surface of the coatings, and the integrity of interfaces between substrate and coating materials. The research effort intends to cover both nickel-based super alloys and ceramic matrix composites (CMC) for developing thermal and sandphobic coatings.