Study Of Burrs On Workpieces And Its Inhibition Method In Micromilling

With the rapid development of biomedicine,defense technology,and aerospace,the demand of miniaturized parts is increasing in various fields,and the surface quality requirements of miniaturized parts are becoming more and more stringent.But especially in micro-machining field,the existence of burrs has become one of the key factors affecting the machining quality and machining efficiency for miniaturized workpieces in the milling procession.How to reduce or suppress the generation of burrs has become one of the most difficult problems in machining.The formation process of burrs is a very complicated nonlinear deformation process in micro machining,and there are many factors affecting its formation.Among them,micromilling parameters and processes are the two most important factors in micro milling.Therefore,in order to reduce or suppress the generation of burrs in the micromilling process,brass and stainless steel are used as experiemntal material,milling forces and burr widths are used as the analysis indexes to study the affecting relationship of four key milling parameters?the axial depth of cut a_p,the feed per tooth f_z,the spindle speed n,and the radial depth of cut a_e?and the burr size in this paper.The single factor,orthogonal,and post processing experiments are carried out.The results of the single factor experiemnt results show that the size of the burr on the side of the down milling is larger than the up milling.Based on the results of single factor experiment results,the orthogonal experiment levels are selected to analyze the size variation rule of burrs in further the orthogonal experiments.The results of brass orthogonal experiment results show that the optimized minimum burr widths is obtained when the paremeters combination is the axial depth of cut a_p of 78?m,the feed per tooth f_z of 1.5?m/z,spindle speed n of 78000min^-1,and the radial depth of cut a_e of 340?m.The significance sequence of key parameters of burr widths from large to small is n,a_p,f_z,and a_e.The results of steel orthogonal experiment results show that the optimized minimum burr widths is obtained with micromilling parameters a_p of 45?m,f_z of 1.0?m/z,n of 48,000 min^-1,and a_e of 200?m.the significance sequence of key parameters for burr widths from large to small is a_p,n,a_e,and f_z.Finally,post processing experiments are further studied and evaluated to reduce the burr size by optimated orthogonal parameters.The experiment results show that the deburring result is best when the radial depth of cut is 500?m,and the post processing experiments can further reduce the burr size significantly by optimizing the burr size.By calculating the average burr widths of the single factor experiments,orthogonal experiments,orthogonal optimization experiments,and post processing experiment results for brass material,the average width of burrs for the brass material is 209.27?m,77.79?m,55.31?m and 19.91?m,respectively.The average width of burrs for stainless steel materials in the single factor experiment results,the orthogonal experiment results,the orthogonal optimization experiment,and post processing experiment results is 362.37?m,213.79?m and 127.31?m,and 14.33?m,respectively.The burr width dimension was significantly reduced in turn in the single factor experiments,orthogonal experiments,orthogonal optimization experiments and further post processing experiments.The study can be not only provide theoretical parameter guidance for deburring in the micromilling,but also provide an effective guidance method to burrs when machining miniature parts.The result of deburring is theoretical significance and practical value.