Study on the reduction of soil adhesion and tillage force of bionic cutter teeth in secondary soil crushing

Fine breakage of topsoil blocks in a seedbed has an important impact on operation quality of planting and harvesting mechanisation. Structure and material of the cutter teeth are one of the key elements in fine topsoil breaking. In order to improve the tillage performance of crushing cutter teeth, a bionic cutter teeth prototype inspired by the badger claw toe is proposed. In addition, the surface of the cutter teeth was modified by anti-adhesion material coating. The simulation model was established in ANSYS/LS-DYNA software and simulated soil cutting process was analysed. The results showed that cutter teeth with bionic structure could effectively reduce the average cutting resistance, cutting stress, soil energy, and maximum cutting resistance, obtaining soil cutting effect. By employing Fourier transform infrared spectroscopy (FTIR), water contact angle combined with abrasion resistance tests, mixed polytetrafluoroethylene (PTFE) and fluorosilicone acrylic acid (FAA) resin coatings after sintering were found to combine well with the cutter teeth. When the coating thickness was 10 μm, the tillage force was the lowest, and the abrasion resistance was the highest, which resulted in best comprehensive performance of cutter teeth. Scanning electron microscope (SEM) images indicated that the coating material can protect the surface and prevent abrasion. Field test results also proved that uncoated and coated bionic cutter teeth had lower energy consumption and soil adhesion, especially for the coated bionic cutter with 10 μm thickness. The results of this study could provide an important reference for designing a more efficient rotating tillage tools.