Improving high-temperature fretting wear performance of GTD-450 blade steels via ultrasonic impact treatment-induced Si3N4 particle implantation

Fretting wear damage to blades, critical components of aeroengines, severely affects their lifespan and reliability. In this study, we explored a novel method (referred to as UITI) to implant particles utilizing ultrasonic impact treatment, which construct a Si₃N₄ particle-reinforced gradient microstructure on the surface of GTD-450 blade steels. Detailed characterization and experimental analysis reveal that the particle gain effect on gradient microstructures emanates from the Orowan bypass mechanism, promoting grain refinement and dislocation accumulation. These factors collectively elevate hardness and compressive residual stress and endow them with excellent thermal stability. Additionally, the UITI-treated sample demonstrated superior fretting wear performance, particularly at an elevated temperature of 400°C, with the wear rate reduced by 60.04 % and 39.48 % compared to the untreated and conventional ultrasonic impact-treated samples, respectively. The strategy presented in this work holds significant potential for improving the high-temperature fretting wear resistance of aeroengine blades, which contributes to enhanced aeroengine lifespan and reliability, as well as reduced maintenance costs.