Recently, high speed machining techniques have become increasingly popular with the high precision accuracy and economic efficiency as the mold industry has grown. High speed machining for high precision and highly efficient processing generally improves the cost of machining by reducing material removal rates (MMR). In addition, the high speed processing process has many advantages, so many researches are to develop high-speed processing technology. It is important to improve the surface roughness of the mold through high speed machining. Many experts are analyzing the process conditions individually for high speed machining. However, most of the researches are focused on planar specimens and materials, so need to studied on freeform surfaces are in the early stages. In order to freeform surface machining process, ball end-mill tools are often used. The tool life of the ball end-mill is a critical factor in the quality of the mold, shape accuracy and productivity. In addition, in the process of using the ball end-mill, machining process is usually done in half of the bottom of the tool. The cutting speed has a high effect on the tool abrasion under the condition that occurs no chipping or chatter. ball end-mill tools have a very long machining time and limited diameter used compared to plain end mills. In addition, the cutting conditions are changed according to the curved surface inclination of the workpiece and the position of the tool blade, so that it is difficult to select the machining conditions and the cutting conditions are set based on the experience of the operator.
In this study, five-axis high speed machining tool was used to identify the high speed machining characteristics of STAVAX. Using the full factorial design of the experimental design method, data on the surface roughness according to the tool type, cutting speed, feed rate, and depth of cut conditions were analyzed and information on the optimum machining conditions of the STAVAX core was obtained. Then, surface roughness were measured four times per workpiece through an interferometry microscope. Measurement data were derived from linear multiple regression analysis of residuals and coefficient of determination. Realized of regression equations at each tool and the linear multiple regression analysis of the AlTiN ball end-mill was obtained with a reliability coefficient about 71%. In addition, the coefficient of determination for linear multiple regression analysis of the TiN ball end-mill was obtained with a very high reliability coefficient about 93%. We have obtained information about the optimal machining conditions for each tool in the STAVAX by experiment. Finally, we had experiments process and analyze of high speed machining on a freeform surface by acquiring optimal process conditions.