Study On Surface Quality And Cutting Process Of Micro Cutting For Small Precision Parts

With the rapid development of mechanical science and technology, miniaturization and precisionhas become an important development trend of mechanical products. As an important part of smallmachinery, manufacturing and processing precision of small precision parts directly affects thedevelopment level and the application degree of small machinery. Because it is low cost, high efficiency,three-dimensional processing capability and other advantages, micro cutting has become the mainprocessing technology of small precision parts.Subject selection of aluminum alloy, stainless steel, through micro cutting experiments, thetypical small precision parts processing technology test, carry out the micro cutting force and vibrationcharacteristic analysis, study on the surface quality, cutting technology research. The main topics of theresearch are:1. Based on the micro-diameter milling cutter straight slot test, cutting force and vibrationcharacteristics of the micro-scale cutting and conventional cutting were compared. Analysis showed that:Compared with conventional scale cutting, fine cutting average cutting force is smaller, but the greater theamount of dynamic fluctuation of cutting force. When the fine vertical milling, runout at cut and cut-outphase is significantly higher than stable cutting stage, cutting parameters are the main factors affecting themicro-diameter cutter runout, compared with the large-diameter end mills, the runout of micro-diameterend mills is more pronounced.2. Through the fine turning, milling single factor and orthogonal experiments of0Cr18Ni9and1Cr18Ni9Ti stainless steel, analyze the influence of cutting parameters on surface quality index aboutsurface roughness, hardness of the surface layer, the tissue changes of surface layer. Studies have shownthat: fine stainless steel turning, milling, the surface layer tissue take place plastic deformation, but thechange did not happen microstructure; The effect law of cutting parameters for fine cutting on the hardnessof the surface layer is similar to conventional cutting; The size of significant degree for parameters on fineturning cutting surface roughness is that: cutting depth> cutting speed> feed rate, As to micro-milling,spindle speed is the most significant, followed by the axial depth of cut and feed rate.3. Based on the foregoing study, by two kinds of the six typical small precision parts cutting process test, the process requires, tool path, process planning on small shaft sleeve and seat body parts areanalyzed, put forward the process specification for two parts efficient precision cutting.The innovative works are:1. To observe the micro cutting surface layer changes by optical microscopy, it can be seen inmetallographic sample three-dimensional model and two-dimensional micrographs, since the smallercutting of micro cutting, tissue surface layer just have plastic deformation, microstructure changes do notoccur.2. For bushings and seat body type, with aluminum and stainless steel as materials, throughcutting process test about six parts having complex structural features, give suitable choice of cutting toolsand machining parameters to develop a suitable process specification.