Optimization of milling parameters to increase surface quality and machining time of the bohler m303 extra

Abstract

Bohler M303 Extra is a material commonly used in plastic injection molds. Improving the surface quality of molded products through the CNC process can reduce production costs by eliminating the polishing and finishing process. Reduction of production costs can also be achieved by decreasing machining time. This paper deals with surface quality optimization and machining time optimization from a variety of toolpath strategies, feed rates, and depth of cut. The machine parameters experiments were based on the L9 orthogonal array of taguchi method. The NC program was generated from the MasterCAM® software and experiments using a Sinumeric 802S/C CNC milling machine. The tool used was Carbide End Mill with TiAlN Coat 12 mm in diameter, with a total of 4 Flutes. The ANOVA results show that the parameters of the toolapth strategy, feed rate, and depth of cut do not have a significant effect on surface quality, but the feed rate parameters have a significant effect on the value of machining time. The result of the S/N ratio calculation places the toolpath strategies parameter as the 1st rank which affects the surface quality while the feed rate parameter is the 1st rank which affects the machining time. The calculation of the s/n ratio also shows that the lower the feed rate value is, the better the surface quality, but the greater the machining time value. Machine parameter setting that gets the optimum surface quality is not the one that produces the lowest or highest machining time values.