The Coupled Influence of Material and Geometric Parameters on Cutting-Edge Micro-Morphology and Wear Property Degradation

Cutting-edge wear is inevitable in the cutting process of the knife. Studying the relationship between the performance of the knife and the cutting-edge wear is conducive to optimizing the design of the knife and increasing its service life. The micro-morphology of the cutting edge during the cutting process was systematically characterized by optical microscopy (OM) and scanning electron microscopy (SEM). The strength of the material matrix was characterized by nanoindentation, and the microstructure of the material was characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The influence of different microstructures and geometry parameters of the cutting edge on edge wear was investigated. The experimental results show that the cutting knife longevity decreases with the increase in the edge angle. When the edge angle is 19°, the durability of knives 1# and 2# is 747.5 mm and 826.8 mm; when the edge angle is 29°, the durability of knives 1# and 2# is 377.8 mm and 486.8 mm. Under the same edge angle, the durability of knife 2# is higher, mainly due to its higher hardness and the presence of more micro-scale M23C6 carbides and nano-scale MC carbides. The edge wear process can be divided into two stages. In the initial wear stage, the edge curling phenomenon occurs, which is the plastic deformation of the edge. In the stable wear stage, plowing and stacking of worn materials are observed, which is the abrasive wear process.