EFFECT OF FEED, CUTTING SPEED, AND TOOL GEOMETRY ON THE MACHINING CHARACTERISTICS OF BEARING BRONZE.

摘要

A comprehensive experimental program designed to investigate the effect of feed, cutting speed, and tool geometry on the surface integrity of CAD 932 bearing bronze was undertaken. The surface of the machined workpieces was examined using profilometry, optical microscopy, and scanning electron microscopy. Tool forces were measured, and the cutting geometry and the temperatures generated in the primary and secondary deformation zones were calculated. Microhardness profiles through the surface region of the machine workpieces were obtained. In addition, several recently developed techniques were modified and were used to determine quantitatively the plastic strain and residual stress distribution in the surface region. Further, X-ray spectrographic analysis was used to determine the chemical nature of the machine surface. The results of this investigation showed that machining leads to the production of a surface and surface region that shows considerable damage.; It was found that the damage varied with feed, tool rake angle, cutting speed and tool wear land length. The causes and origin of the various forms of surface damage were identified and discussed in detail.; The results were interpreted in terms of the cutting geometry, the mechanics of chip formation, the dynamics and thermodynamics of cutting, and the interaction between the tool nose region and freshly machined workpiece surface. The work provided new, important, information on the behavior of lead inclusions in the work material.