Study on the Laser Modification of Plasma Sprayed Thermal Barrier Coatings to Create a Peg-nail Structure

摘要

In this study an innovative peg-nail structured laser modification was carried out on thermal barrier coatings (TBCs) which were fabricated by a NiCoCrAlYTa bond coat and a YSZ top coat sprayed by air plasma spraying (APS). Results indicate that the laser modified surface has significantly improved roughness compared with as-sprayed coatings especially using the multi-pulsed laser beam. The laser modified YSZ region consists of a fully dense columnar microstructure. Due to the peg-nail structured laser modification which penetrated the whole top coat and partial bond coat, the average bonding strength of as-sprayed TBCs was improved from 37 to 52 MPa.