An Investigation of Chipping Propagation on Carbide Tool in End Milling for Prototyping

Machining plays an important role in the prototyping process, and the carbide tools are often used in cutting tough metals under higher cutting speeds. Given the high degree of freedom and uncertainty in prototyping, conventional machine tools are generally favored by the machinists, and its low rigidity is more likely to cause chipping or breakage of the cutting edge in using carbide tools. However, due to the rapid development of chipping and the ever-changing toolpath in prototyping, the understanding of this type of tool damage is very limited from previous studies. To address this issue, the objective of this study is to experimentally investigate the chipping initiation and progression on the carbide tool under the prototyping circumstances. The experimental results indicate that the chipping develops differently at different locations on the cutting edge and under different cutting conditions and propagates rapidly when the maximum width of the local chipping reaches the critical value. It was also found that the chipping propagation is influenced by the interactions between the chipping and the flank wear and chipping among different flutes. To consider all those factors into chipping characterization and monitoring in milling, a combined failure criterion has been proposed in this study.