Distribution of unit forces on the tool edge rounding in the case of finishing turning

Abstract

An experimental investigation was conducted to determine the effects of tool cutting edge geometry on the cutting forces in finish turning, where the applied feed and depth of cut are small and often comparable with the tool edge radius. If a tool with large tool edge radius is used in finish turning, the ploughing effect begins to determine the machined surface. This paper presents the results of analytical considerations concerning the unit forces on a cutting edge. The aim of this paper is to indicate possibilities of modelling the unit forces and stress distribution based on cutting resistance. The forces calculated in the feed and cutting speed directions were projected onto the tangential and normal directions of the rounded cutting edge surface. An important assumption in all the considerations was that the thermo-mechanical properties of the materials used remained constant. The minimum thickness of cut was defined, and some characteristic points were identified dividing the cutting zone into three subregions: where a chip is formed, where the machined surface is formed and an unstable region.

Recent Advances in Micro/Nano-cutting: Effect of Tool Edge and Material Properties

“…The unit forces, such as unit tangential force and unit normal force acting on the contour of the cutting edge, are investigated with tool edge radius range from 4 to 40 lm [92]. The minimum UCT and the unstable region are identified by the distribution of the unit forces in the tool edge.…”

The study on minimum uncut chip thickness and cutting forces during laser-assisted turning of WC/NiCr clad layers

“…In this study, the zeroth tangential force method, proposed by Storch and Zawada-Tomkiewicz [38], is applied and extended to the oblique cutting of WC/NiCr clad layers. During the oblique cutting with the rounded corner of insert (r ε > 0), the instantaneous uncut chip thickness values are variable in function of width of cut, which affects the distribution of cutting force components and thus hinders the estimation of minimum uncut chip thickness.…”

“…According to the authors of [37,38], the location of stagnant point A is described by the occurrence of the minimum cutting energy or the tangential force increment equaled to zero. In this study, the zeroth tangential force method, proposed by Storch and Zawada-Tomkiewicz [38], is applied and extended to the oblique cutting of WC/NiCr clad layers.…”

“…The necessary model parameters were experimentally obtained from the orthogonal cutting tests. The similar method has been applied by Storch and Zawada-Tomkiewicz [38]. The proposed model was formulated for the orthogonal turning and based on the determination of critical angle in the cutting edge's cross-section, corresponding to zeroth tangential force.…”

Minimal thickness of cut layer in the vicinity of the cutting edge rounding

“…Some of these analyzes concern the development of the model based on material and geometric simplification assumptions [2,3,[6][7][8]. Other tests refer to conducting experiments and determining the minimum thickness of the cutting layer by contacting direct measurement of the parameter, microhardness analysis and analysis of the contact zones of the tool and the work surface using optical measuring instruments [1,4,5,9].…”