Mechanism of the Effects of Microstructure Refinement and Residual Stress Regulation on the Wear Resistance of Planetary Roller Screw Pairs

Planetary roller screw pairs are core precision-transmission components in high-end electromechanical equipment, and their wear resistance directly affects service life, motion accuracy, and operational stability. This study investigates the mechanisms by which microstructure refinement and residual stress regulation improve wear resistance in screw, roller, and nut materials. A hybrid material configuration is adopted, with a TC4 titanium-alloy screw, GCr15 bearing-steel rollers, and a composite nut comprising a carburized steel internal ring gear and a 7075-T6 aluminum-alloy base. Microstructure refinement increases screw surface hardness, improves plastic deformation resistance, reduces adhesive and fatigue wear, and slows crack propagation. Residual compressive stress regulation offsets external contact tensile stress in the rolling-sliding contact region and suppresses crack initiation and propagation. The synergistic optimization of surface integrity and contact mechanical properties reduces wear failure from multiple dimensions. The findings provide theoretical and technical support for precision transmission systems used in robotics, aerospace servo systems, and electromagnetic/electromechanical actuation equipment.