Cutting Rate-Tool Life Characteristic Functions for Material Removal Processes—Part 2: Verification and Applications

The experimental verification, interpretations, and applications of the concept of cutting rate-tool life (R-T) characteristic functions are presented in this paper. Two statistically designed experiments, one on sawing and the other on milling, verifying the concept are described. The analytical and geometrical interpretations of the concept, including the existence of optima in the R-T domain, are presented. The applications discussed include economic selection of machining conditions, economic tool life determinations, comparison of machining response, objective function for adaptive control, and maximization of material removal at a desired level of surface integrity. The concept can be applied to other machining responses of conventional as well as nontraditional material removal processes.

Cutting Rate-Tool Life Characteristic Functions for Material Removal Processes—Part 1: Theory

The existence of cutting rate-tool life (R-T) characteristic functions for material removal operations is introduced in this paper. This new concept enables a comprehensive development of a theory for economic optimization encompassing commonly used criteria of cost, production rate, and profit rate in machining when more than one cutting variable is involved. The theory provides conditions for the existence of economic optima, all of which must lie on the R-T characteristic curve for a given operation. The analysis of the theory is carried out for one and two independent cutting variables. For these two cases, it is proven that the locus of the tangent points of constant cutting rate and constant tool life curves describes the R-T characteristic curve, and also that the tool life is maximum along a given constant cutting rate curve at the point of tangency and vice versa. This geometric interpretation provides useful application of the concept as shown in Part 2.

Determination of Geometric Properties of Coated Abrasive Cutting Edges

The surface topography of a coated abrasive was measured by a special designed profilometer with an oscillating stylus, revealing very detailed geometric features of the peaks. The criterion for a peak to be a dynamic active cutting edge is analyzed and the results are applied for the identification of active cutting edges of the measured profiles. The distributions of some geometric properties of the active cutting edges as heights, distances, rake-angles and wear-lands are evaluated for six grades of coated abrasives.

Analysis of Temperature Field in Chip

A solution is presented for the temperature field in the chip under experimental edge conditions in the contact zone and at the upper chip face. The pattern of the temperature gradient in the chip normal to the tool face while turning steel with hard-metal tools is analyzed.