Tribological Properties of Shot Peening/Bionic Texture Multi-modified Layers on Ti/Mo-doped 65Mn Steel Plow Surfaces
The rapid wear failure of 65Mn steel plow surfaces under sandy/clayey tillage conditions, driven by abrasive wear and soil adhesion, necessitates advanced surface modification strategies. This study investigates a triple synergistic modification combining Ti/Mo doping, shot peening, and bionic texturing to enhance tribological performance under water-soil solution lubrication. 65Mn steel ingots with and without (0.1wt.% Ti + 0.2wt.% Mo) doping were cast, heat-treated (normalizing at 830°C, quenching at 800°C, tempering at 265°C), and subjected to ultrasonic shot peening (0.35 MPa, 300% coverage) and laser-textured bionic patterns (37% texture ratio) inspired by pangolin scales. Tribological tests under 20 N and 50 N loads revealed that Ti/Mo doping refined grains and formed TiC precipitates, increasing hardness from 414.7 HV to 496.9 HV and reducing friction coefficient and wear rate by 6.2–6.7% and 41.6–38.7%, respectively. Shot peening alone increased surface roughness (Ra 0.027 to 0.173 μm) and hardness (496.9 to 579.7 HV), reducing wear rate by 33.9–49.8% despite a 9.3–10.3% increase in friction coefficient. Bionic texturing alone reduced friction and wear by 8.6–7.1% and 25.6–40.9%, but limited by texture edge collapse. The combined shot peening/texture treatment reduced friction and wear by 24.1–20.0% and 74.1–77.0% versus doped-only samples. The full multi-modified layer achieved the lowest friction coefficients (0.104, 0.112) and wear rates (0.91×10⁻⁵, 1.24×10⁻⁵ mm³/(N·m)), representing reductions of up to 28.7%, 25.3% and 84.8%, 85.9% compared to the original sample. This “strong matrix-hard surface-antifriction interface” system offers a viable strategy for extending the service life of agricultural soil-engaging components.