Modeling of Cutting Forces and Cycle Times for Micromachined Components

Micromachining employs specialized machine tools and cutters to achieve micro-scale (<1 mm) features with uncut chip thicknesses and surface finish requirements ranging from a few micrometers to several hundred nanometers. Machining in this regime is often dominated by ploughing and rubbing phenomena over shearing at the cutting edge and requires microstructural effects to be taken into consideration. The ability of a micromachining process to achieve geometry and surface finish requirements depends on several factors including workpiece material microstructure, tool geometry, tool integrity during the cutting process, and the machine tool. This paper presents preliminary developments in physics-based modeling for predicting the micromachining behavior of aluminum alloys. This model was validated by comparing cutting force predictions against experimental machining tests. Experiments encompass multiple tool diameters, uncut chip thicknesses, and depths of cut. New advancements aimed at accurately predicting cycle times within a physics-based toolpath-level analysis framework are also presented. The model takes into account acceleration, deceleration, and jerk characteristics of the machine tool controller to improve overall cycle time predictions.