激光辅助微铣削TC4钛合金中刀具磨损及切削力研究

发布时间：2018-11-07 17:51

【摘要】：TC4综合性能优越,在航空航天、生物医疗等领域有着广泛的应用。微铣削TC4等难加工材料时,刀具的磨损和破损是面临的主要问题之一。将TC4用于高精度微型惯性器件等精密件的微加工时,刀具磨损导致加工成本高而且很难得到高质量的材料表面。采用激光辅助微铣削,可以提高TC4等难加工材料的切削性能,减轻刀具磨损、提高刀具寿命、降低切削力。刀具磨损是多种磨损机理作用的结果,激光的引入使刀具的磨损机理变得更加复杂。本文将以激光辅助微铣削TC4刀具磨损及切削力为研究对象展开研究。首先,对微铣削与激光辅助微铣削TC4这两种加工方式下的无涂层硬质合金微铣刀的刀具磨损进行分析,确定其主要磨损机理。针对不同的磨损机理,结合微铣削切削特点,考虑TC4材料性能随温度的变化进行理论推导,建立相应的磨损率数学模型。将不同磨损机理的磨损率模型组合,得到微铣削与激光辅助微铣削的刀具磨损率数学模型。然后,利用建立的刀具磨损率数学模型,基于Fortran语言编写磨损率公式,结合有限元仿真软件Deform-3D的二次开发技术,分别对微铣削与激光辅助微铣削TC4进行三维仿真,研究主轴转速、每齿进给量、刀具刃口半径等因素对刀具磨损、切削力及切削区域温度等结果的影响。并对微铣削与激光辅助微铣时的刀具磨损、切削力、切削区域温度等结果进行对比分析。最后,进行无涂层刀具的微铣削、激光辅助微铣削TC4实验以及涂层刀具的激光辅助微铣削TC4实验。利用扫描电镜等设备对实验前后微铣刀的形貌、磨损形式及刀尖元素能谱进行检测。研究激光辅助下主轴转速、每齿进给量对刀具磨损、铣削力的影响,并与相应的仿真结果进行对比。仿真能够正确反映各参数对刀具磨损、切削力的影响趋势,能够大致反映切削力的数值。同时对激光、刀具涂层作用下的切削力、刀具磨损程度的变化情况进行了实验研究。
[Abstract]:TC4 has a wide range of applications in aerospace, biomedical and other fields because of its superior comprehensive performance. The wear and breakage of cutting tools is one of the main problems in micro-milling of difficult materials such as TC4. When TC4 is used in micro machining of precision parts such as high precision micro inertial devices, cutting tool wear results in high cost and high quality material surface. Laser assisted micro-milling can improve the cutting performance of difficult materials such as TC4, reduce tool wear, increase tool life and reduce cutting force. Tool wear is the result of various wear mechanisms. In this paper, the wear and cutting force of laser assisted micro milling TC4 tool are studied. Firstly, the tool wear of uncoated cemented carbide micro-milling cutter under two machining modes of micro-milling and laser assisted micro-milling, TC4, is analyzed, and the main wear mechanism is determined. According to the different wear mechanism and the characteristics of micro-milling, considering the change of TC4 material properties with temperature, the mathematical model of wear rate is established. The wear rate models of micro-milling and laser-assisted micro-milling are obtained by combining the wear rate models of different wear mechanisms. Then, using the established mathematical model of tool wear rate, the wear rate formula is compiled based on Fortran language, and combined with the secondary development technology of finite element simulation software Deform-3D, the 3D simulation of micro-milling and laser-assisted micro-milling TC4 is carried out respectively. The effects of spindle speed, feed rate per tooth and cutting edge radius on cutting tool wear, cutting force and cutting zone temperature were studied. The results of tool wear, cutting force and temperature of cutting area were compared and analyzed between micro-milling and laser assisted micro-milling. Finally, the experiments of micro-milling without coating, TC4 experiment with laser assisted milling and TC4 experiment with laser assisted micro-milling of coated tool are carried out. Scanning electron microscopy (SEM) was used to detect the morphology, wear and energy spectrum of micro milling cutter before and after the experiment. The effects of laser assisted spindle speed and feed per tooth on tool wear and milling force were studied and compared with the corresponding simulation results. The simulation can accurately reflect the influence trend of various parameters on tool wear and cutting force, and can roughly reflect the value of cutting force. At the same time, the change of cutting force and tool wear degree under the action of laser and tool coating are studied experimentally.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG54;TG714

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