Invastigation of the effects of tool nose radius and cutting edge geometry on surface roughness and cutting forces in milling operation

In this study, machining tests was carried out on AISI 1040 carbon steel work pieces. The machining tests were performed on a CNC vertical machining center equipped with a dynamometer. Test specimens were prepared on universal milling machine according to the dimensions 70 X 50 X 15 mm. Cutting tools with three different edge geometries (SPMT 1204 AEN; SPMW 1204 AENA-57; SPMT 120408-D51) has been used in experiments. The first one has been only chamfered with 1,4 mm, the second insert was chamfered 1,4 mm and have a radius of 0,5 mm, the third one was only have a radius of 0,8 mm. Milling tests have been carried out at 0,5 mm and 1 mm depth of cuts. The feed rates are 0,1; 0,15; 0,2 mm/tooth and cutting speeds are 120; 140; 200; 240 and 280 m/min. The influences of cutting tool nose radius and cutting edge geometry on cutting forces and surface roughness have been examined by carrying out individual tests for each cutting condition. According to the cutting forces versus cutting speed graphics, ?only chamfered? inserts have given the best results. The inserts with ?chamfer and radius? together have been created the highest cutting forces. After the surface roughness results were appraised, it has been seen that ?only chamfered? cutting edges have best roughness values. The worst surface roughness has been performed by using of the insert beveled with radius. The insert which has only a radius with 0,8 mm generally has performed average values of cutting forces and surface roughness at all conditions. Increasing cutting velocity has caused a little increase on cutting forces but it has degreased the surface roughness much more. Consequently, it has been seen that cutting force and surface roughness are proportionally affected by the changes of feed rate.