Characteristic Variations of Chip Morphology and Cutting Forces in Face Milling with Flat-Faced and Grooved Tool Inserts

Abstract

The modeling of face milling operations has been traditionally focused on using flat faced tools with an assumption of perfectly straight chip formation. However, curled chip formation is a common phenomenon in practical milling operations, and it has a profound effect on machining performances. A new analytical model that takes into account the chip curling effect in milling operations is proposed in this paper. It is shown that chip morphology and machining parameters, such as the chip up-curl radius, the chip thickness, and the tool-chip contact length, simultaneously change with varying undeformed chip thickness during each tooth cycle. The proposed model is validated through milling tests. Good agreement between theory and experiments has been reached. A comparison of the average resultant force among three types of commercially available tool inserts is made to demonstrate the effect of tool insert chip-groove geometry on milling performances.