Precision surface characterization for finish cylindrical milling with dynamic tool displacements model

Abstract

This paper presents a novel approach to surface roughness parameter estimation during finish cylindrical end milling. The proposed model includes the influence of cutting parameters, the tool's static run out and dynamic phenomena related to instantaneous tool deflections. The modeling procedure consists of two parts. In the first stage, tool working part instantaneous displacements are estimated using an analytical model which considers tool dynamic deflections and static errors of the machinetool-holder-tool system. The obtained height of the tool's displacement envelope is then applied in the second stage to the calculation of surface roughness parameters. These calculations assume that in the cylindrical milling process, two different mechanisms of surface profile formation exist. Which mechanism is present is dependent on the feed per tooth and the maximum height of the tool's displacement envelope. The developed model is validated during cylindrical milling of hardened hot-work tool steel 55NiCrMoV6 using a stylus profiler and scanning laser vibrometer over a range of cutting parameters. The surface roughness values predicted by the developed model are in good agreement with measured values. It is shown that the application of a model which includes only the effect of static displacements gives an inferior estimation of surface roughness compared to the model incorporating dynamic tool deflections.

The application of response surface method to optimization of precision ball end milling

“…The surface roughness of the machined surfaces can be affected by the kinematic-geometric parameters, frictional effects in the tool-work material inter-face [1], process stability [2], plastic-elastic deformations of work material induced by the ploughing mechanism [3,4], as well as the thermal phenomena in the cutting zone [5][6][7]. However, one of the most significant factors affecting milled surface quality is tool-work piece relative displacement (vibrations) [8].…”

Turning process monitoring of internal combustion engine piston’s cylindrical surface

“…The appearance of these phenomena is strictly correlated with the generation of cutting forces and vibrations, which in turn can significantly affect the deterioration of the machined surface quality [6,7]. On the other hand, the force and vibration signals can be applied for the machining process monitoring.…”

The study on dynamic properties of monolithic ball end mills with various slenderness

“…Nevertheless, many researches [1][2][3] show that fundamental problems occurring during ball end milling in finish conditions are the excessive surface roughness and surface location errors, as well as the intense tool wear [22]. The deterioration of surface quality during machining can be attributed to machine tool-cutting process interactions, as: milling kinematics [4,5], the loss of process stability [6,23], elastic-plastic deformations of workpiece [7,8], as well as the tool's working part displacements (vibrations) [9,10]. Nevertheless, the vibrations seem to be the most influential factor affecting the milling accuracy.…”