Deformation Mechanism And Experimental Research Of Typical Polycrystalline Metal Micro Cutting

Micro products are becoming more and more widely used in the fields of national defense industry,medical health,aerospace and microelectronics.Therefore,the demand for the key micro parts of micro products is becoming more and more urgent in various fields.At present,in the main processing methods of manufacturing small and small parts,MEMS technology has a single processing material and relatively low relative precision.It can not process three-dimensional small and small parts with complex shape,and the cutting of three-dimensional small parts by conventional machine tools has the disadvantages of large space occupation and high energy consumption.Micro machining technology can be used to process the micro parts of a variety of engineering materials with complex three-dimensional structure.It has the advantages of low cost,high efficiency and high precision.It can fundamentally solve the existing problems in the processing mode of small and small parts.Therefore,micro cutting technology is the foundation of micro fabrication and the source of innovation.Development and perfection.In this paper,the deformation process of the typical polycrystal metal micro cutting is deeply analyzed,the micro cutting model and the calculation formula of micro cutting force are established.Through the self developed micromachining test system,the orthogonal right angle micro cutting test and the micro cutting simulation test of the micro cutting through the cutting simulation software ABAQUS are carried out to the micro cutting model.The formula of micro cutting force is further verified and optimized.Because of the inability to ignore the blunt circle of the tool in the process of micro cutting,this paper analyzes the deformation mechanism of the material according to the three parts of the cutting tool,which are divided into the front blade,the blunt circle and the back surface of the tool.The calculation formula of the chip deformation coefficient is given.It is concluded that the chip can be reduced by reducing the blunt circle radius of the cutting edge of the cutting tool.Deformation coefficient.The micro cutting model and the calculation formula of micro cutting force considering the influence of the blunt circle of the cutting edge are established.The influence of the blunt circle of the cutting edge on the cutting force is theoretically analyzed.The cutting force F_r increases with the increase of the blunt circle radius r_n of the cutting edge,the cutting force F₁ of the front knife surface decreases and the force F_h of the cutter face increases when the cutting depth is fixed..The influence of the blunt radius of the cutting edge on the stress field and the equivalent plastic strain field during the micro cutting process is studied by the finite element software ABAQUS cutting simulation.The minimum cutting thickness of the aluminum alloy Al6061-T6 is 27%left right of the blunt circle radius of the cutting edge through the method of rate field stagnation.The effect of the cutting depth relative to the cutting speed on the micro cutting force is larger and the micro cutting force is not linearly increased with the increase of the cutting depth.The scale effect in the micro cutting is verified by the deep research on the unit cutting force,and the macro and micro parameters under different cutting parameters are verified.The chip morphology is analyzed.With the increase of the cutting thickness,the chip is from the broken end to the strip to the banded chip,and the chip folds and cracks are less and less.The cause of the scale effect is analyzed at the angle of the chip,and the micromorphology of the chip root is studied.It is found that there is a phenomenon of fibrosis and grain pullout in chip roots.