Effects of External Hydrostatic Pressure on Orthogonal Cutting Characteristics

Abstract

In this paper, effects of external hydrostatic pressure on the cutting characteristics are investigated. Orthogonal cutting experiments are conducted in a high pressure chamber using four kinds of materials; two of them are brittle materials and the others are ductile materials. Chip formation processes of soda glass specimen are studied by in-situ observation. It is confirmed that chip formation style changes from the crack type to the segmented chip type, then to the continuous chip type with the increase of hydrostatic pressure. Furthermore, cutting forces under various hydrostatic pressures are measured, and effects of hydrostatic pressure on the cutting forces are studied. It is found that hydrostatic pressure increases the cutting force in the brittle mode cutting of glasses, but does not affect the cutting force in ductile mode cutting. In case of ductile materials, hydrostatic pressure increases the cutting force of polycarbonate too, but does not affect the cutting force of pure aluminum. Based on those experimental results, mechanism of hydrostatic pressure effects on cutting characteristics is discussed.