Simulation And Experimental Study On Surface Formation Mechanism Of Micro-milling Parts

With the development of science and technology,the miniaturization of products has become a trend of development.More and more miniature products are appearing in the fields of aerospace,rail vehicles,and defense industries.Due to the increasing demand for tiny parts,micro-miniature parts processing technology has become the subject of today's industrial development research.Among many micro-machining technologies,micro-milling technology is one of the most widely used and most simple processing methods.Micro-milling is not simply a reduction in size.Its machining process and machining mechanism have been very different from conventional milling.It is necessary to establish a cutting model that meets the micro-milling characteristics.In this paper,the change law of cutting force in micromachining and the influencing factors of surface roughness of micro-parts are the basic research contents.The following aspects are studied:1)The calculation formula of surface roughness considering the minimum cutting thickness was obtained,and the cutting force model near the tip circular arc was established.Under the influence of plough shear force,flow stress and elastic recovery,the micro-milling force theory was established.model.2)Using ABAQUS finite element modeling simulation software,finite element cutting simulation analysis of a typical aluminum alloy 6061-T6 material.Through two-dimensional orthogonal cutting simulation,it is determined that the minimum cutting thickness of aluminum alloy 6061-T6 is about 27% of the radius of the obtuse circle of the cutting edge.Selecting different blunt radius of the cutting edge for simulation study,it is found that the micro-cutting force increases with the radius of the obtuse circle,which provides a theoretical basis for selecting the radius of the obtuse circle of the cutting edge.Reproduce the three-dimensional milling process,designed an orthogonal simulation program,and concluded that within a certain range,the micro-milling force decreases with the increase of the spindle speed and increases with the increase of the feed amount per tooth.The axial depth of cut increases.3)Using self-developed miniature three-axis milling machine,through single-factor experiments and orthogonal tests on aluminum alloy 6061-T6 material,the spindle speed,feed per tooth,and axial depth of cut were studied in actual machining.The influence law of force,as well as the influence law on the surface roughness of the machined workpiece,the experimental conclusion obtained is consistent with the finite element simulation conclusion,and further verified the correctness of the experiment.4)The results of the experiment were subjected to range analysis and analysis of variance,and the degree of influence of each factor on the experimental results was determined.The conclusion was reached that the degree of significance of the cutting forces in the three directions was in the following order: axial cutting depth> per Gear feed > Spindle speed.The degree of significance of the degree of surface roughness is in the order of: axial depth of cut> per tooth feed> spindle speed.