Mechanistic force modeling in finish face milling of additively manufactured Inconel 625 nickel-based alloy

Abstract

Additively fabricated parts can be manufactured to a near-net shape and typically only have to undergo finish operations to achieve the desired tolerances and surface finish. As heat-resistant super alloys (HRSA) are particularly difficult to machine, additive manufacturing techniques for fabrication of HRSA workpieces are of high interest. However, additively fabricated parts exhibit different properties than conventionally manufactured counterparts, including variations in machinability depending on their build direction and processing parameters. Machining force modeling for additively fabricated materials should be developed for making a correct choice of machining strategy and cutting parameters. A mechanistic model for cutting force prediction is proposed in this work. Mechanistic force modeling methodology was presented for different build orientations and discussed in detail. Validation of model output for uncut chip thickness and cross section area was performed with the use of 3D CAD uncut chip models. In-depth experimental testing was conducted to gather force data for modeling and evaluation purposes. The effects of feed rate, cutting speed, scan strategy rotation, and cutter-workpiece orientation were analyzed and discussed. Modeling results were compared with gathered experimental data, showing a good agreement of simulation and experimental results, proving the validity of proposed mechanistic force model for machining additively manufactured material.