Investigation machinability of aisi 52100 bearing steel by ultrasonic turning method

In this study, effects of lubrication techniques and cutting parameters on performance characteristics in conventional and ultrasonic turning of AISI 52100 steel, machinability of AISI 52100 steel, were investigated as experimentally, numerically and statistically. In order to determine machinability, effects of independent variables on workpiece surface roughness, surface topography, machining temperature, cutting force, tool wear/life, chip form, chip thickness ratio and machining index were determined. Experimental studies were carried out using cemented carbide and cubic boron nitride (CBN) cutting tools under machining conditions such as 50, 100 and 150 m/min cutting speeds, 0.1 mm / revolution constant feed and 0.5 mm constant cutting depth, under cooling method as both dry machining and minimum quantity lubrication method (MQL). Al2O3 nano particle cutting fluid was used in minimum quantity lubrication method. In Ultrasonic Turning experiments, 5 and 10 µm as amplitudes and 20 and 30 kHz as vibration frequencies values were applied to cuttingtool. Cutting force and machining zone temperature Analysis were performed in the Deform software program. Experimental and Deform Software results were compared each other. Analysis of Variance (ANOVA) was performed to determine significance effects of independent variables on dependent variables. According to experimental results; it has been determined that vibration which applied to cutting tool improved surface roughness, reduced cutting forces and cutting tool wear under all conditions. In Ultrasonic Turning which carried out under dry machining, it was determined that with increasing cutting speed, cutting temperature results exceeded more than conventional turning. However, lower cutting zone temperature values were obtained in Ultrasonic Turning experiments carried out under MQL Method compared to dry machining. Furthermore, increasing values of vibration frequency, workpiece surface roughness and cutting force were reduced. While flank wear was commenly observed in CBN cutting tool, cemented carbide cutting tools did not show regular flank wear, but also fracture, notch wear, and built up edge on tool were intensively observed. According to surface topography results, traces due to feed in conventional Turning formed dominant surface texture, while micro indentation and protrusion were observed in Ultrasonic turning. While discontinuous chip types were observed at low cutting speed, continuous and helical types chip formed respectively in conventional and Ultrasonic turning. Higher machining index values occured in Ultrasonic Turning operations according to conventional turning. Infinite element analysis, the cutting temperature and forces were obtained very close to experimental results. According to the analysis of variance; cutting speed is the most important independent variable effecting on surface roughness, cutting temperature, tool wear and chip thickness ratio, machining method is the most important independent variable effecting cutting force and cooling method is the most important independent variable effecting the machining index.