Self-Grinding Silage Knife Strengthened with Ni–WC Alloy Prepared by Laser Cladding

Abstract

The working environment of agricultural cutting tools is poor, and the operational quality and efficiency are reduced after they become blunt. This study aimed to develop a high wear-resistant agriculture knife with a long life. A Ni–WC alloy, wear-resistant layer was prepared using laser cladding technology on one side of the cutting edge of a 65 Mn silage knife. A self-grinding edge was formed when the cladded knife was used, which improved the cutting quality and service life of the knife. The microstructure, phase, composition, and hardness distribution of the cladding layer were detected and analyzed. The impact toughness and wear resistance of the laser-cladded samples were analyzed, and the cladded knife was tested in the field. The results show that a cladded layer with a dense microstructure formed metallurgical bonds with the substrate. The microhardness was uniform across the cladded layer, and the average hardness of the micro Vickers was approximately 1000 HV(0.2), which was approximately three times the hardness of the substrate. The impact toughness and wear resistance of the coated knife were obviously higher than those of uncoated knives. The field tests showed that compared with a conventional 65 Mn knife, the self-grinding knife with laser cladding could maintain its sharp cutting shape after operation for 76 h, which greatly extended the service life of the knife. This study improved the service life of an agricultural cutting tool, which enhanced the cutting performance and efficiency at the same time.