Research On The Micromilling Processes

With the rapid development of science and technology, the microcutting technology has developed unprecedentedly. The microcutting technology is defined as an advanced technology in which the features of parts whose dimensions are in the range of 0.1mm~10mm are machined in micro scale by the high precision CNC machine tools. On the one hand, micro-fabrication is based on MEMS technology which is more advanced to some extent but also is limited in the range of targets whose geometrical dimensions are 2D and 2.5D. On the other hand, the MEMS equipments are very expensive which could not be afforded by the general research organizations. Furthermore, it is only economical for them to be used in the mass production. Therefore, the micromachining technology was proposed. It has proved that the micromachining technology could process the parts with complex shapes economically and efficiently.The micromilling process studied by the nonlinear analysis software ABAQUS is discussed in this paper. The 2D orthogonal cutting model and 3D model are constructed in this paper. Firstly, the simplified 2D orthogonal cutting model, the real 3D micromilling model, the model of the friction between the tool and the chip, and the chip separation principle are adopted in the simulation. The Johnson-Cook constitutive model, the Johnson-Cook failure mode, and the shear failure model are also used in the simulation. Secondly, the finite element analysis of the material AISI4340 is conducted. The different shapes of the chips derived from the different failure parameters are studied in the paper. The distribution of cutting force and cutting heat of different kinds of chips on the surface of the workpiece are also studied. Thirdly, the results of the finite element analysis are testified by the experiments. It is proved that the 3D micromilling model constructed in this paper is valid and the distribution of the stress on the surface of the workpiece is in accordance with experiment results.To further testify the validity of the theoretical simulation model, the experiments are carried out and compared with simulation results. The validity of the simulation results are proved by the experimental results.