Coatings for Polymer Turbine Blades

Erosion resistant coatings on High Temperature Polymer Matrix Composites (HTPMC) are of great interest for aerospace turbine blade applications. HTPMC has tremendous potential to reduce the weight and cost of military aircraft turbine engines if its durability in service environments can be demonstrated. In this study, we report evaluation of erosion resistant thermal spray coatings using conventional weight loss methods in order to compute the net erosion volume loss and erosivity and also report their thermal cycling durability. HVOF technique was employed to apply Tungsten Carbide erosion protection coatings and a special bond coat process was used to enhance adhesion between coating and HTPMC substrate. During erosion tests the coated polymer composite coupons were subjected to runway sand and aluminum oxide erodent at room temperature and 600^oF at two different angles of incidence. The erosion test data and the thermal cycling data on coupons is reported alongwith results of coated HTPMC blades.