Research On The Influence Of Cutting Edge On Critical Cutting Conditions In Micromilling

Micro-miniature parts have the advantages of small size and light weight.The demand for micro-miniature parts in modern medicine,electronic communications,defense industry,aerospace and other fields is increasing.Micro-milling processing technology has the advantages of low milling force,high processing accuracy and wide range of applicable materials.It has become an important method for processing micro-small parts.Due to the size effect in micro-milling,this will affect the surface quality of the machined workpiece.In the case of micro-milling,there is a phenomenon of critical undeformed cutting thickness(minimum cutting thickness phenomenon).Tools with different cutting edges have different critical undeformed thickness during micro-milling.When the cutting thickness is greater than or equal to the critical undeformed cutting thickness,Overcome the size effect.Therefore,in this dissertation,for three materials of 304 stainless steel,H59 brass and 6061 aluminum alloy,the finite element simulation and experimental research of micro-machining with three blade radius radii tools were carried out,and the critical undeformation of micro-milling with different blade radius radii was analyzed.The influence rule of cutting thickness,so as to avoid the size effect in micro-milling and promote the development of micro-machining technology.First of all,choose the process method in which the radial cutting depth is greater than the tool radius.At this time,the minimum undeformed cutting thickness is equal to the feed per tooth.Finite element simulation models were established with 304 stainless steel,H59 brass and 6061 aluminum alloy and tools with cutting edge radii of 5?m,2?m and 1.5?m,respectively.The finite element simulation software DEFORM-3D was used to carry out micro-milling simulation research.The study found that when the critical undeformed cutting thickness is reached,stable and continuous chips are produced,the milling process is stable and the milling force tends to decrease or grow slowly.Secondly,based on the parameters obtained by the simulation,a micro-milling test is conducted.The milling force is calculated by collecting the milling force data,and the surface roughness of the workpiece is measured.The obtained milling force and surface roughness values are plotted as a graph,and the change trend is observed,and the milling force change trend is compared with the simulated milling force change trend.The study found that when the critical undeformed cutting thickness is reached,the milling force tends to decrease,and the surface roughness reaches a minimum at this time.The results obtained by the simulation are consistent with the results obtained by the test,which verifies the correctness and rationality of the cutting parameters.Finally,the critical cutting parameters of each cutting edge radius tool when micro-milling three materials are summarized and compared,and the influence rules of different cutting edge radius tools on the critical cutting conditions(critical undeformed cutting thickness)are analyzed.The research results of this topic have certain guiding significance for selecting reasonable micro-milling tools after given workpiece machining characteristics,or selecting reasonable micro-milling parameters after giving tool attributes.