A quantitative model that correlates sharpness retention and abrasive wear of knife blades

Abstract

The relation between sharpness retention and the wear of knife blades is a fundamental technical problem to be elucidated in industry, as it can help improve the design of knife blades and extend their service time. In this study, the wear mechanism of steel blades with varied blade angles were investigated following classic wear methodology. Simple linear relationship between actual applied force F, cycle number n and volume of material loss Vloss were found and analyzed. The wear rates (1.5–1.98 × 10−4 mm3/(Nm)) and wear constant K (∼10−3) were determined, and the wear process the blade tip suffered was identified as three-body abrasive wear. Moreover, the sharpness retention of a blade was evaluated via the Cumulative Cutting Depth (CCD) of paper cards, which closely correlates to the evolution of blade tip geometry. The cutting mechanism was found to shift from cutting-up to wear-out as the contact pressure underneath the blade tip falls below a critical value, e. g 136 MPa for the paper cards. Considering both these two cutting mechanisms, a generalized quantitative model has been established to describe the CCD in terms of wear resistance of materials, blade angle and initial width of blade tip.