Effects of tool edge radius on chip formation during the micromachining of pure iron

The smoothed particle hydrodynamics simulation model of micromachining of industrial pure iron was established to study the effect of tool edge radius on chip formation in this paper. The process of chip production was studied by particle displacement method, and cutting force and stress were analyzed. Meanwhile, the mechanism of chip formation was revealed. The simulation results show that the tool edge radius has significant effects on chip formation in micromachining. When the depth of cut is 0.16 times of the tool edge radius, the chips begin to produce. And the minimum cutting thickness decreases with the increase of the ratio of the cutting depth to the tool edge radius, which means that chips are more easily to be produced with the decrease of the tool edge radius. Meanwhile, the larger the tool edge radius is, the wider the stress distribution area is and the greater the fluctuation of the cutting force is. Finally, values of the minimum cutting thickness under different ratios obtained by the theoretical formula are basically consistent with the simulation results, verifying the correctness of the simulation results. This paper provided valuable insights into reasonable selection of tool parameters for improving machining precision.