Taguchi Approach for Achieving Better Machinability in Unreinforced and Reinforced Polyamides

Polyamide composites find wide applications in engineering fields due to favorable properties and hence replaced many traditional metallic materials. In order to increase the properties, the glass fibers are added to unreinforced polyamides. Even though polyamides are produced as near net shapes, machining is required to get the finished products. Thus, the selection of tool and cutting conditions is important in the machining of unreinforced and reinforced polyamides. This article presents the application of Taguchi's quality loss function approach, a multi-response optimization method, for achieving better machinability during turning of both unreinforced polyamide (PA6) and reinforced polyamide with 30% of glass fibers (PA66 GF30). The analysis of means (ANOM) and analysis of variance (ANOVA) on multi-response signal to noise (S/N) ratio are employed to determine the optimal parameter levels and to identify the level of importance of the parameters. The ANOVA results showed that the cutting speed is the most significant factor affecting machinability. Taguchi optimization results suggest that the optimal value of feed rate and cutting speed should be kept at a low level, whereas a polycrystalline diamond (PCD) tool is beneficial over cemented carbide (K10) for machining of both PA6 and PA66 GF30 polyamides to achieve better machinability.