Investigation of machinability of austempered ductile iron by using ceramic cutting tools

In this study, machinability of austempered ductile irons by using ceramic cutting tools are investigated. Cutting forces, tool wear and surface roughness are considered as the machinability criterion. Two different austempered ductile iron materials and as-cast material were used during the experiments. The ADI specimens were austenised at 900ºC for 120 min. and then the specimens were austempered at 250 ºC and 375 ºC for 120 min. The cutting forces measured for four different cutting speeds (100, 200, 300, 500 m/min.), 1 mm depth of cut and 0.1mm/ rev. feed of rate. The wear tests were carried out two cutting speed (340, 240 m/min), 1,5mm depth of cut and 0.32 mm/rev. feed of rate are to be constant. In the experimental results, the least tool life was obtained in austempered specimens at 250 ºC but the greatest tool life was determined in the KGDD which is not carried out heat process. In addition, the cutting forces were increased with the decrease of austempered temperature. The biggest cutting forces were obtained in machinability of the austempered specimens at 250 ºC. Besides, ceramic cutting tools showed better performance as compared to cermet tools.