Research On Design And Manufacturing Of PCD Micro Milling Tool

Micro milling is a material removal process in meso & micro scale range. The cutting thickness is close to cutting edge radius, and micro milling is affected by serious size effect, result in some problems such as low machining accuracy, bad surface quality, and tool fracture. The surface quality, machining accuracy and tool life are influented by the basic parameters of micro milling tool. Micro milling tool is the key factor to realize the high precision micro milling. Design and manufacture of micro milling tool would be taken breakthrough. And then, the problems of micro milling which are low milling precision and bad surface quality would be solved. Therefore, The research on design theory and manufacturing technology of micro milling tool is implemented.The main research contents are as follows:(1) On the basis of analyzing the advantages and disadvantages of existing design and manufacture of micro milling tool, a design principle of micro milling tool was established by controlling specific energy, and then a P3 design flow of micro milling tool which was based on precision, production and performance were proposed to improve the precision of tool geometry, to reduce the risk of tool fracture and the cost of tool manufacturing.(2) The stiffness of micro milling tool was analyzed by the cantilever beam in mechanics of materials. Stiffness analysis results showed that the deformation of tool edge is the most part of total deformation. And then, the basic structure and parameters of micro milling tool with diameter less than 0.5mm were designed. According to application requirements, tool parameters(material, structure and degree) can be obtained. A variety of tool edge structures of micro end mills are designed.The finite element analysis of micro tool was carried out to analyze the strength and stiffness.(3) The process problems of manufacturing micro tool had been broken through, which were including high frequency induction brazing, edge forming by WEDM, edge sharpening by precision grinding. And then, the PCD micro milling tools with different angles and different diameters between 0.08mm~0.5mm were manufactured successfully. Cutting performance and tool life of the developed tools was obviously better than that of existing commercial micro milling tool. The Taguchi experimental design and grey relational analysis was combined to analyze multi-input and multi-output experiment. The different dimensions of the experimental quality characteristics were achieved the dimensional normalization to solve the optimization problem of multiple quality characteristics of the grinding process parameters.(4) The micro milling experiment of oxygen free copper and tugsten carbide were conducted by the developed PCD micro tools. The influence of milling process parameters on the machined surface quality, burr, cutting force were studied to achieve the precision & micro machining of oxygen free copper. The optimization of micro milling process parameters was implemented by analyzing surface roughness, burr, cutting force to obtain mirror surface of tugsten carbide under the ductile mode.