A treatise in material characterization in the metal cutting process. Part 1: a novel approach and experimental verification

摘要

Everyday practice of cutting process planning requires reliable cutting force estimates, which currently can be obtained only from process-dependent machinability databases. The greatest obstacle to develop a more basic, efficient approach is a lack of understanding of material behavior under unique deformation conditions of cutting. Since metal cutting involves the physical separation of the chip from the rest of the workpiece, this paper defines the metal cutting process as the purposeful fracture of workpiece material. Part one of this two-part paper presents a novel approach of characterizing the resistance of workpiece material to cutting. It is shown that the strain at fracture is the most general material behavior characteristic. The experimental results show that the strain at fracture measured in incremental compression is consistent with that measured in orthogonal cutting when all deformation variables are properly accounted for and that, contrary to the results obtained using other kinds of material characteristics, the resistance to cutting of workpiece material in orthogonal cutting is not affected by high strains, strain rates and temperatures occurring in the cutting process.