The effect of cutting tool vibration occuring when machining on surface roughness

The aim of this study is to determine the optimum cutting conditions by examining the influences of cutting tool vibrations on surface roughness during machining. For this purpose, machining tests were performed under dry conditions using coated cementide carbide cutting tolls having four different chip breaker forms (SA, MA, MS, GH). The machining tests were carried out at four different cutting speeds (200, 250, 300, 350 m/min) at constant cutting depth (2,5 mm) and three different feed values (0,15 mm/rev, 0,25 mm/rev, 0,35 mm/rev). A total of 48 machining tests were performed on AISI 1050 steel 40 mm diameter. All the tests were performed by machining 50 mm length on the workpiece. Cutting forces and vibrations were measured during the tests. Surface roughness values of the machined surfaces were measured after the tests. The surface roughness values increased with the vibration acceleration values. This shows the effect of vibration over the surface roughness. As analyzed the chip breaker performances at different cutting speeds; the best results were obtained at 200m/min cutting speed with MS chip breaker form and the second best results obtained with SA chip breaker form. For all the chip breaker forms, 250 m/min cutting speed and 0,25 mm/rev feed values were found to be optimum cutting parameters.Key Words: Vibration, cutting force, surface roughness, machining