Investigation of form deviations of high-speed steel (HSS) products under turning-milling operation using automatically programmed tools

Abstract

Investigation of form deviations of cylindrical high-speed steel (HSS) products made under turning-milling operation by CNC-controlled lathe machining center (further CNC) with auxiliary drive axle is given. Technological support of high-speed steel products quality made by turning milling operation on a CNC lathe machining center with an auxiliary drive axle takes effect owing to the shape deviation reduction. Planning of experiments was carried out according to the Taguchi method for four factors and three levels. The experiment was conducted on a DMG NEF 400 lathe machining center having an auxiliary drive axle, which allows machining modes to be performed with a rotating tool. Samples of high-speed steel R6M5K5-MP were used. Machining operation was made according to the scheme of orthogonal turning by milling. A core carbide mill CCM 4321 was used as a cutting tool. Out-of-roundness (lobing) was estimated using optical method. All measurements were carried out on the Bruker Contour GT-K1 optical profilometer. Surface micro-dimensions were measured by optical scanning of the surface. Surface optical scanning resulted in a point cloud was obtained that mirrors micro-dimensions of the cylindrical profile of the piece partmeasured section. The obtained data obtained made it possible to measure a lobing that occurs under orthogonal milling turning method. The influence of cutting modes on the shape and size of the maximum peaks of the cut is proved. The smallest facet pattern value is observed for milling width a_e in the range of 3,5...5,5 mm with high feed values for the tooth f_z and low cutting speed v_c. The largest cut height is observed at the average values of a_e, a_p, v_c. It is an optical profilometer that is an effective means of measuring facet patterns or lobings. The results obtained in the work allow predicting form deviations of a blank made of high-speed steel under turning milling operations on CNC machines. The results of the study can be used to improve rotary cutting tools quality in the tool industry.