The Effect of Tool’s Rake Angles and Infeed in Turning Polyamide 66

Abstract

Polyamide PA66 has been adopted by a variety of industries, and engineering fields. It is used in machinery part production due to its good properties. Machining is the most commonly used processing technique when high quality of part dimension and surface is required. There is a lack of knowledge about the impact of the tool’s rake angles when turning polyamide PA66, therefore, this study aims to define an optimal condition that can provide the highest performance in machining polyamide PA66 at the lowest cutting force. The impact of the tool’s side rake angle, back rake angle, and cutting depth on cutting force was studied during turning polyamide PA66 with the HSS tool. Three levels were considered for each variable and Taguchi's Orthogonal Array (OA) was used to design nine test configurations. The tests were performed experimentally on a conventional lathe machine. The resultant cutting force was calculated as the response data. The values were converted to signal-to-noise (S/N) ratio to facilitate the analysis using the Taguchi method and analysis of variance (ANOVA). Accordingly, the cutting depth showed the greatest impact on cutting force (57.12%), followed by the side rake angle (27.9%) and back rake angle (8.21%). An optimal condition set to turn polyamide PA66 at the lowest cutting force (Fc) is identified as 1 mm depth of cut, side rake angle αs = 21°, and back-rake angle αb = 8°. Finally, the optimal condition set was evaluated by conformation tests, and the results agreed with the calculations to a large extent.