Micro-geometrical characteristics of the cutting edge as the intersection of two rough surfaces

The sharpness of the cutting edge plays an important role in the cutting process, but is not well-defined because of a variety of possible cutting process applications. The edge sharpness strongly depends on the geometrical characteristics of the edge, as well as other important factors: the tool and work (target) materials, the cutting edge dimensions (linear and angular), and the kinematics of the process. Considering the cutting edge as the intersection of two flank roughnesses, it is possible to evaluate the 3D distribution of the actual edge knowing only both flank profiles and edge angles. This may support decisions concerning the sharpening technology. The proposed metric of the edge rectilinearity is the dimensionless edge length ratio. Such an approach was applied for the assessment of the micro-geometrical properties of surgical scalpel blades. Analyses demonstrated the suitability of the edge length ratio for the evaluation of the cutting edge micro-geometry.