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High quality surfaces with transparency are required for manufacturing of plastic products. In cutting of polymer materials, surface quality is sometimes deteriorated by tarnish and/or unequal spaces of area on a surface. The cutting parameters should be determined through understanding of surface finish characteristics. This paper presents an optimization approach in milling of polycarbonate with polycrystal diamond tools in terms of the surface finish. Surfaces are finished with changing the feed rate and the clearance angle of the tool. The surface finishes, then, were observed to classify the deterioration type into welding, adhesion, and the unequal space of cutter marks with measurement of the surface profiles. The measured surface roughnesses are decomposed into the theoretical/geometrical term and the irregular term induced by the thermal and the dynamic effects. A map is presented to characterize the irregular term for the feed rates and the clearance angles. Because the surface roughnesses are measured at discrete sets of the cutting parameters in the actual cutting tests, the process design cannot be conducted to optimize the operation parameters. Therefore, a neural network is applied to associate the cutting parameters with the irregular term in the map. An approach is presented to determine the number of hidden nodes/units in the design of the neural network. Three prominent areas of welding, adhesion, and unequal spaces of the cutter marks, appear in the map of irregular roughness. The map of the surface roughness is made to optimize the cutting process. The applicable feed rates and clearance angles are determined for the tolerable surface roughnesses. The gradient information in the map is used to evaluate the stability/robustness of the surface quality for changing the parameters. The optimum parameters were determined to minimize the gradient information in the applicable feed rates and clearance angles.

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Functional surfaces have been widely used for control of physical and/or chemical properties of substances on the surface. In the manufacturing industries, some of micro fabrication approaches such as laser processing have been applied to form textured surfaces, which control the surface functions with topographies. This study presents the surface texturing in cutting with micro-scale structured end mills. Micro-scale nicks are fabricated on the cutting edges of PCD (Poly-Crystalline Diamond) end mills in laser finishing. The cutting operation is conducted to form the chips on each nick with the cutter axis inclination in the feed direction. An analytical model is applied to control the surface structure for the spindle speed, the feed rate, the nick geometry and the inclination angle of the cutter axis. Then, the surface structures were fabricated in the actual cutting process. The machining operation in this study is available in fabrication of the micro-scale structures at high production rates and the structures shape can be controlled in the surface simulation.