On friction and wear performance of ground surfaces of ultra-high-strength steel under ultrasonic vibration-assisted grinding process

Ultra-high-strength steel is primarily used in aerospace transmission gears, where the quality of the ground surface and surface wear resistance significantly influence gear performance. The quality of the ground surface significantly impacts friction, wear behavior, and overall wear efficiency. Ultrasonic vibration composite machining technology effectively enhances the quality of machined surfaces. Therefore, this study conducted ultrasonic vibration-assisted grinding tests on ultra-high-strength steel to investigate the friction and wear properties of the ground surface. Both ultrasonic vibration-assisted grinding (UVAG) and conventional grinding (CG) were applied to the carburized surface of ultra-high-strength steel, comparing temperature and surface hardness under various grinding parameters. The results indicate that compared to CG, UVAG's separation characteristics allow better penetration of grinding fluid into the grinding arc, reducing the grinding temperature by over 33% and increasing surface hardness by up to 7%. Analyzing the friction and wear performance reveals that UVAG surfaces maintain a lower coefficient of friction under various loads. The abrasion marks on UVAG surfaces are narrower and shallower compared to CG surfaces, reducing the wear rate by over 15%. The superior surface morphology and hardness of UVAG-treated surfaces effectively inhibit wear progression. This study provides technological insights for high-quality machining of ultra-high-strength aerospace transmission gears.