【作者】 童利东；

【导师】 梁迎春；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2006， 硕士

【摘要】 随着人们对微小型产品需求的增加和科学技术水平的发展,利用微细铣削加工技术,制造复杂3D几何形状微小零件变得日益广泛。目前,世界各主要国家已经在微细铣削领域开展了广泛的研究,微小型机床得到了研制,表面质量、切削力、刀具的磨损和寿命、切屑状态以及微小零件的加工能力等领域是研究的重点。本文将在已研制的微小型三轴立式铣床基础上,通过有限元和实验分析,研究微径铣刀的力学特性、磨损机理和刀具寿命。以求增加刀具的耐用度,提高铣削效率,保证微细铣削的加工质量,为实现高效加工提供理论指导和试验依据。首先,利用有限元方法,对微径铣刀的力学特性进行分析。通过模态分析,研究刀具的固有频率和振型;以及通过静力学分析,研究微径铣刀的应力和变形特点。其次,通过大量的刀具磨损实验,利用扫描电子显微镜和能谱仪,研究了TiAlN涂层硬质合金微径铣刀(直径0.5mm),在铣削硬铝LY12、高弹性合金钢3J21和不锈钢时,刀具的磨损机理;以及无涂层硬质合金微径铣刀,铣削硬铝LY12时的刀具磨损机理。发现涂层脱落、刀尖破损、扩散磨损为微径铣刀的主要磨损形式。最后,通过实验研究微细铣削的刀具寿命问题。分析了顺铣平面时,主轴转速分别为160000r/min、140000r/min、120000r/min时的刀具磨损特性;逆铣平面时,主轴转速为140000r/min时的刀具磨损特性。在此基础上,绘制了ln -lnT关系曲线,建立了切削速度与刀具寿命T的关系式。发现逆铣时刀具磨损得比顺铣时的快;切削速度越大,刀具磨损得越快,但其影响要比常规铣刀的小。vc vc更多还原

【Abstract】 With the increasing need for microminiaturization product and the development of the technology, Micro milling technology plays an more and more important role in complicated 3D micro parts manufacture. Currently, more and more research has been carried out on Micro milling technology in developed countries. Micro machine tools which focused on surface quality, cutting force, wear, cutting life, chip, and the processing capacity have been manufactured.Based on the micro three-axis vertical milling machine, On purpose of increasing the tool life, improving efficiency, assuring the quality, and providing a theory and experiment basis, method of finite element analyze and experiment has been used. Meanwhile the mechanics identity, wear mechanisms, and cutting life of the micro tool have been studied.First of all, the mechanics characteristics of micro milling cutter have been analyzed using FEM. The inherent frequency and mode of vibration have been studied. The stress and distortion characteristics of the micro milling cutter have been discussed.Secondly, through substantial tool wear experiments, and the using of SEM and alpha ray spectrometer, the wear mechanisms of micro milling cutter have been researched, using the TiAlN coated carbide alloy microtool (diameter 0.5mm), and duralumin LY12, high flexibility alloy steel 3J21, stainless steel as the workpieces. The wear mechanisms of uncoated carbide alloy micro cutter, with the workpiece of LY12, have been researched, too. The coat shed, tool tip breakage, diffusive wear have been observed as the main form of tool wear.Finally, the life of micro milling cutter has been studied. The tool wear characteristics have been analyzed, in the condition of down milling, with the spindle speed of 160000r/min, 140000r/min, 120000r/min, as well as in the condition of up milling with the spindle speed of 140000r/min. With the date of the experiments, the curve of ln ~ lnT has been plotted, the expression of ~ T has been established. It is found that the wear rate of up milling is faster than that of the up milling. The faster of the cutting speed, the faster of the tool wear rate, but the affect of the cutting speed is smaller that of conventional milling cutter. vc vc更多还原