Experimental investigation of tooling system effects on hole quality in boring operations

In this study includes to determine that the tooling system together with cutting parameters how affects the hole quality using experimental design method in boring operations. The tooling system contains that the insert geometry, the tool material and the overhang length of boring tool. The hole quality involves that the surface roughness of the hole, the deviation from circularity and linearity of the hole. The trial combinations obtained from the Taguchi experiment design method were used to carry out to get the best optimum results with the minimum cost and time. The results of trials displayed a meaningful relation and parallelism with the avaliable catalog data. Otherwise, the applicability, productivity and the reliability of conditions of the trial combinations were tested. The trials were carried out on the AISI 1040 material used frequently in manufacturing industry. The samples were made 60 mm at diameter and the each lenght of the sample part at 60 mm. Each sample part drilled all along 36 mm at diameter. Total number of the samples were 27. Taguchi?s standart orthogonal array called L27 was selected and used since the most suitable orthogonal array for the five factors with three levels for each one. The test factors were selected such as cutting speed (Vc , m/min), feedrate (f , mm/rev), depth of cut (ap , mm), cutting tool holder material (Tt) and overhang length and diameter ratio of the boring tool (L/d ratio, mm). The tests data were analyzed by Minitab 15 statistical analyze software. By means of the Minitab software, the experimental results were transformed into the three-dimensional (3D) graphics and these 3D graphics were examined. According to obtained results from the tests, the feedrate factor has been the most significant effect on the surface roughness of the hole and secondary effect occured by the cutting tool material were measured. The deviation from circularity has been affected mostly by the feedrate (f) factor, secondary effect created by the depth of cut (ap) were determined. It was seen that the amplitution of cutting vibrations has been affected mostly by cutting speed (Vc) and the depth of cut factor has the most significant effect on the linearity of bored hole.