Abstract
In mechanical micromachining, understanding the chip formation mechanism is critical to optimize the machining parameters and improve the workpiece performance. In this work, the entire slot micromilling process on Al6061-T6 by one flute carbide cutter was simulated by means of finite element method (FEM). Under this machining parameters set, the chip was found to be segmented type. The simulation results matched with the experimental results on the burr and chip morphologies and the cutting force. The segmented chip formation process was described from the viewpoint of chip velocity. The variations of the tool chip contact length (l T ) and the shear band length (l S ) were studied in detail. The chip formation mechanism was studied quantitatively by means of hybrid analytical-FEM approach. Through calculating the chip moments, “tool rake moment” M Tool and “shear band moment” M Work, it has been found that the main reasons of the segmented chip formation are the variations of the l T and l S . The Arcona–Dow model (AD model) and Merchant model (MM model) were utilized to calculate the M Work respectively. The AD model performed better in the microscale than the MM model. In the segment generation occasion, the average chip velocity value in chip bending process was much greater than the one before chip bending, which was about the cutting speed. The chip root velocity was almost constant in the entire micromilling process, and the chip tip velocity increased greatly in the chip bending instant due to the chip angular acceleration. The chip angular acceleration was acquired, respectively, from FEM and the analytical method based on the M Tool and M Work_AD calculations. The agreement of these two approaches validated the correctness of the chip moments calculations. The results of this work were useful to understand the micromilling mechanism and improve the workpiece performances.
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This work is financial supported by Chinese 985-II foundation, Northeastern University outstanding PhD project foundation (200705), French Research Ministry, and Lorraine Region Council.
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Wang, J., Gong, Y., Abba, G. et al. Chip formation analysis in micromilling operation. Int J Adv Manuf Technol 45, 430–447 (2009). https://doi.org/10.1007/s00170-009-1989-8
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DOI: https://doi.org/10.1007/s00170-009-1989-8