Occurrence of catastrophic tool wear patterns through systematic thermomechanical modeling

Abstract

To achieve optimal tool performance, it is essential to not only comprehend the wear patterns during the steady wear stage but also the final one where catastrophic wear patterns are usually involved. However, previous focus has been put individually into them, thereby the mechanism connections in between have not yet been completely demonstrated. This study aims to bridge this gap by developing an analytical model based on the slip-line theory and imaginary heat source formulations for worn tools with cutting edge geometry extracted from the steady wear stage. The model computes the thermomechanical loads on the tool surface, which are then incorporated into a mechanism-based wear rate model that has been carefully calibrated. Finally, a nodal-displacement algorithm is used to iteratively determine the further tool edge profiles until the final wear stage. The sequential edge profiles demonstrate that the most significant wear increments occur at the rear of the tool flank wear land, resulting in a gradually deepening and widening notched region. These predictions are consistent with experimental findings where a notch belt wear is observed to grow along the tool main cutting edge during the steady wear stage, which ultimately decreases the edge toughness and leads to catastrophic wear patterns.