Manufacturing and preparation of micro cutting tools: influence on chip formation and surface topography when micro cutting titanium

Cutting edge preparation is widely used in conventional cutting processes. It stabilizes the cutting edge and is done to improve coating adhesion. However, the preparation of the cutting edge is accompanied by an increase in cutting edge roundness. This rounding results into larger effective negative rake angles, especially at small undeformed chip thicknesses, as they prevail in micro and ultraprecision processes. In this paper, the influence of the cutting edge micro geometry at very small undeformed chip thicknesses is investigated. A sharp, a rounded and a chamfered cutting edge are manufactured and examined at undeformed chip thicknesses of 0.4 mu m, 5.2 mu m and 10.0 mu m. The resulting chip formation, forces and surface quality are examined when orthogonal cutting commercially pure titanium, a material used for example for bio-applications.