Investigation on the use of cutting temperature and tool wear in the turning of mild steel bars

Abstract

The paper is concerned with the development of a data acquisition system for the measurement of temperature used for metal cutting. In this study, machining tests were performed and an analysis of the temperature and wear of the cutting tool is presented herein. In metal cutting operations, the wear of tools is generated largely due to the heat emitted from the cutting zone. Therefore, a coolant is often used to cool down the cutting area and protect the cutting tools. However, because of environmental concerns, engineers now try to avoid using cutting coolants and perform cutting operations in almost dry conditions. In this study, a mild-steel round bar was turned at various feed rates, depths of cut and cutting speeds. A data acquisition system was built to record the cutting temperature while turning the bar. From the study, it is evident that certain combinations of cutting parameters result in higher temperatures than those produced in other experiments. It was established that the depth of cut and cutting speed at their highest values (1 mm and 250 m/min, respectively) contribute largely to the high surface temperature, while the effect of feed rate is intangible. Increasing the cutting speed results in an increase in the cutting temperature. A similar result was observed when the depth of cut was increased. However, increases in feed rate did not significantly cause increases in cutting temperature. In addition, cutting inserts were examined under a scanning electron microscope (SEM) to quantify the tool wear in each experiment. A correlation between tool wear and temperature is clearly noticed. The study concluded that the combination of variations in cutting speed and depth of cut results in severe tool wear action on the tool’s flank face as a result of the intensive heat generated.