Enhancing service life of thermal barrier coating via high-current pulsed electron beam processing: Surface reconstruction of bonding layer and crystalline inheritance of ceramic layer

Thermal barrier coating (TBC) is a critical thermal protection technology in aerospace engines. Controlling the structural stability of the TBC interface and suppressing the uncontrolled growth of thermally grown oxide (TGO) have long been challenges in this field. This work introduced an innovative method to synergistically control the morphology and microstructure of the metal/ceramic interface in the TBC system using high-current pulsed electron beam (HCPEB) technology, aiming to achieve steady-state growth of TGO and extend the service life of TBC. In this study, an arc-ion-plated MCrAlYX metallic coating was modified by HCPEB irradiation to induce remelting-polishing and microstructure reconstruction of the coating surface. This treatment effectively reduced surface roughness by approximately 83% and eliminated defects such as particle clusters and microcracks. The remelted layer, with a refined microstructure and a thickness of approximately 7 μm, was used to control the genetic growth behavior of the YSZ ceramic coating deposited by electron beam-physical-vapor deposition. As a result, the ceramic coating formed with more uniform columnar grains and reduced roughness. Thermal cycling oxidation testing at 1100°C demonstrated that the HCPEB-modified TBC produced a dense, stable Al₂O₃-based TGO layer at the interface, improving oxidation resistance and suppressing spallation. The enhanced structural integrity and interface stability of the modified TBC system contribute to a significantly extended thermal-cycling lifespan, highlighting the effectiveness of HCPEB in advancing TBC for high-temperature applications.