To reduce the draught force of a traditional planar potato digging shovel (DZ), a biomimetic potato digging shovel (YS), inspired by the mole rat’s digits, is designed, using the biomimetic macroscopic surface modification method. The finite element simulations, soil bin experiments, and field experiments for DZ and YS are conducted to explore the factors affecting draught force and to verify the feasibility and effectiveness of the biomimetic potato digging shovel. Results show that the soil–shovel interaction models predict the draught force well, but the simulations for the soil rupture distance ratio need to be further improved. The studied factors all have a great influence on the draught force of DZ and YS and they follow the order of cutting speed > digging depth > mounting angle. For the single shovels, YS, compared with DZ, increases the draught force at a low mounting angle but decreases the draught force by over 8.41% when the mounting angle is higher than 30°; for the grouped shovels, the draught force and fuel consumption of YS, compared with those of DZ, decline by over 13.33% and 9.18%, respectively. The reasons for the reduction in the draught force of YS are to make the soil mass tend to move upward and to change the soil’s state of motion and stress continually; thus, the compaction to the soil is reduced, and the soil becomes easier to be broken.

To improve the tribological properties of a potato digging shovel (PDS), Ni65-based coatings with rare earth oxides additions were fabricated on 65Mn# steel via High-Velocity Oxygen-Fuel (HVOF) flame spraying, the effect of macroscopic surface shape of PDSs on their wear resistance of PDSs was examined, and finally a kind of PDS with a specific macroscopic surface shape and satisfied wear resistance was obtained. The addition of CeO₂ and Y₂O₃ decreased the defects in coatings, refined the microstructure, made hard phases distributed more uniformly and ultimately improved coating properties. According to the XRD analysis results, the Ni65-based coatings were composed of the matrix phase γ-Ni and hard phases formed by Cr, Fe and Ni with B, C and Si. More Cr₇C₃ phases were detected in coating B than in coating A, but the phases related to Y and Ce were also not detected because of the low content in both EDS and XRD analyses. Heat treatment and HVOF flame sprayed coatings both increased the hardness of specimens, and coating A (621HV_1.0) provided a hardness nearly equivalent to that of the heat treatment specimens (617HV_1.0), while coating B provided the highest hardness (664HV_1.0). For all specimens, laser surface texturing (LST) structures weakened their corrosion resistance. However, the Ni65-based self-fluxing alloy coatings significantly improved the corrosion resistance of specimens, and coating B provided the best corrosion resistance. SEM images show that the main wear mechanism for worn specimens was abrasive wear, and less wear signs were observed on the surface of coating B. Abrasive wear examinations indicate that specimen BJ had the best wear resistance and, compared with specimen W, the mass loss of specimen BJ decreased by 28.56% and 20.83% at relative sliding speeds of 2.35 m/s and 3.02 m/s, respectively. However, considering the negative effect of LST structures on the corrosion resistance of specimens, the processing techniques of specimen A and specimen B are more applicable to PDSs. The macroscopic surface shapes affected the wear resistance of PDSs and ZF had the lowest mass loss but the highest draught force; comparatively, YS had a better balance on the draught force reduction and wear resistance. Finally, YS with coating B, which decreased the mass loss by more than 27.17%, is recommended in this paper. On the whole, the conclusions in this paper provide a reference for the design of potato digging shovels with lower draught force and better tribological properties.