Experimental analysis of the effect of vibration on the surface roughness in turning of AISI 4140 steel with ceramic cutting tools

AISI 4140 (42CrMo4) steel materials are widely used in automotive, aircraft and defense industries due to their high strength, high toughness, and good hardenability. For this reason, it is very important to obtain a good surface quality in turning hardness of these high steels. In this experimental study, it is aimed to investigate the effect of vibration on the surface roughness of untreated, conventional heat treated and tempered AISI 4140 steel samples (Ø100x250 mm) with 18, 45 and 52 HRc hardness using ceramic cutting tools. Cutting parameters were selected four different cutting speeds (120, 160, 200 and 240 m/min), three different feed rates (0,05, 0,10 and 0,15 mm/rev) and cutting depth (0,2 mm). In order to determine the ideal cutting parameters, to make the turning process more efficient and to measure the occurring vibrations, the data were obtained online from the ceramic cutting tool by using accelerometers in three axis (x, y and z directions). Surface roughness measurements were performed to determine the effect of vibrations during the turning process on the surface quality of the samples. According to the data obtained, the most important cutting parameter affecting vibration and surface roughness values was found to be the feed rate. Compared to other samples, it was found that the vibration of 45 HRc hardness sample was lower and the surface quality was better. It has been observed that lower vibration and surface roughness values have been obtained in tempered samples which have high hardness values in the turning process with ceramic cutting tools and therefore better surface quality can be obtained. Keywords: AISI 4140, Ceramic tool, Surface roughness, Turning, Vibration.