Modeling the Material Microstructure Effects on the Surface Generation Process in Microendmilling of Dual-Phase Materials

Abstract

The anisotropic behavior of the material microstructure when processing multiphase materials at microscale becomes an important factor that has to be considered throughout the machining process. This is especially the case when chip-loads and machined features are comparable in size to the cutting edge radius of the tool, and also similar in scale to the grain sizes of the phases present within the material microstructure. Therefore, there is a real need for reliable models, which can be used to simulate the surface generation process during microendmilling of multiphase mate rials.This paper presents a model to simulate the surface generation process during microendmilling of multiphase materials. The proposed model considers the effects of the following factors; the geometry of the cutting tool, the feed rate, and the workpiece material microstructure. Especially, variations of the minimum chip thickness at phase boundaries are considered by feeding maps of the material microstructure into the model. Thus, the model takes into account these variations that alter the machining mechanism from a proper cut-. Assoc. Editor: Komel Ehmann. ting to ploughing and vice versa, and are the main cause of microburr formation. By applying the proposed model, it is possible to estimate more accurately the resulting roughness because the microburr formation dominates the swface generation process during microendmilling of multiphase materials. The proposed model was experimentally validated by machining two different samples of dual-phase steel under a range of chip-loads. The roughness of the resulting swfaces was measured and compared to the predictions of the proposed model under the same cutting conditions. The results show that the proposed model accurately predicts the roughness of the machined surfaces by taking into account the effects of material multiphase microstructure. Also, the developed model successfully elucidates the mechanism of microburr formation at the phase boundaries, and quantitatively describes its contributions to the resulting swface roughness after microendmilling.

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“…Where A w is the surface area of the contact with cavity sidewalls, L is the tooth load, and r c is the tool nose radius; correspondingly, E and ν are the polymer's Young's modulus & Poisson ratio, respectively, δ represents the maximum peak to valley distance generated with the micro drill. Provided that feed rate ( f) and tool nose diameter employed during the micro drilling process are all given, the following equation (11) used to calculate the δ [106].…”

Precision micro-milling process: state of the art

“…This will lead to further development of the micro-milling process as a whole and offer insights into better microstructure design when micro-milling. With regard to surface roughness, Elkaseer et al [ 136 ] presented a model to simulate the surface generation process in micro-milling of multiphase materials. They confirmed that their developed model could be used to predict the surface quality after machining under various machining parameters and could further be used to optimize the process for multiphase materials.…”

Development and experimental validation of an analytical model to predict the demoulding force in hot embossing

“…Given that the feed rate, f , spindle speed, V, and tool nose radius used during the micro drilling process are known parameters, it is possible to calculate δ as follows (Elkaseer et al 2012):…”