Experimental Evaluation of Influence of Tool Wear on Quality of Turning

This article is devoted to the evaluation of the effect of tool wear on the quality of the machined surface in turning on the metal cutting machines. The modern level of measuring equipment allows to obtain a qualitative assessment of the roughness indices of the treated surface. For the experiment, the Triebworx T4HD profilometer-contourograph and the optical three-dimensional microscope Contour ELITE were used as measuring instruments. The equipment was provided by Optec. The results of the experiment made it possible to obtain a qualitative tool wear characteristic on the back face and to associate it with a characteristic that reflects the changes in the surface quality of a part in time. As the main conclusion formed by the results of processing the data obtained in the experiment, it is argued that the quality of the treated surface depends little on the degree of tool wear until the moment of approaching the catastrophic level of wear. With the approach of wear to the catastrophic point and its further increase, the quality of the treated surface sharply deteriorates. The dependencies obtained in the work as a whole coincide with the realistic approach to the evaluation of the dynamics of the processes taking place in metal cutting machines. According to this approach, during the cutting process, several evolutionary sections are observed: the tool run-in and stabilization area, both of the dynamics of the control system and the quality of the parts produced, and the sharp increase in the tool wear (catastrophic wear) in which the dynamics of the system becomes unstable, and the quality of the treated surface sharply deteriorates.