【作者】 边疆；

【导师】 朱波；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 钛合金以比强度高、机械性能及抗蚀性良好而成为制造飞机和发动机中的主要构件,如压气机叶盘、风扇叶轮等重要薄壁类零件;但由于钛合金的难加工性及薄壁零件刚性差等原因,加工过程中容易出现颤振引起的鱼鳞状表面缺陷,降低加工质量与切削效率,降低刀具、机床的使用寿命。因此,对钛合金薄壁件加工的切削稳定性研究具有较高的实际意义。首先,本文分析了再生颤振及强迫再生振动的机理,并给出相应的动力学模型;给出了切削稳定性判据,采用稳定性极限图作为对切削稳定性分析求解的表示方法。对多自由度系统的稳定性进行分析,给出了多自由度系统稳定性极限图的绘制方法,并分析了系统频响特性、刀具几何参数及切削用量对切削系统稳定性的影响,给出了稳定性极限的评价方法。其次,阐述了整体叶轮叶片的加工方法,并分析了整体叶轮叶片作为薄壁结构的加工工艺特性,指出了整体叶轮叶片精加工时存在的问题及寻找切削稳定区域的方法。最后,通过TC11钛合金叶片铣削试验,研究了改变切削用量时,切削力和振动信号的变化规律。结合试验数据,分析了不同切削参数下的加工稳定性,并以分析结果作出了试验条件下的稳定性极限图;研究了球铣刀刀具几何角度对TC11钛合金叶片铣削力及振动的影响,分析了改变球铣刀刀具前角、第一后角、第二后角和螺旋角时,叶片铣削力和振动信号的变化规律,为刀具角度的优化选择提供依据。更多还原

【Abstract】 Titanium alloy is used to make components of airplanes and engines because of its high strength, well mechanical properties and anticorrode, such as compressor’s disk, fan impeller; However, because of the poor machinability of Titanium alloy and the poor rigidity of thin-walled component, it is usually produce fish scale-type defect due to chatter, and it decreases the efficiency of processing and cutting, shortens life expectancies of cutting tools and machine tools. Therefore, it is significant to research on the cutting stability of thin-walled Titanium alloy.Firstly, the paper analyzed the regenerated vibrate,forced vibration, and provided respective dynamics model;It provided the criterion of stability, using the lobe chart for analyzing the the system steady or not.It analyzed the stability of multi-degrees of freedom, provideing the method of protracting the lobe chart, analyzed the influence of frequency characteristics, geometry parameters of ball-end mill and cutting parameters for system stability,and provided the evaluation method of its limit of stability.Secondly, it expounded the method of machining for integrated impeler blades,and analyzed the technics speciality integrated impeler blades as thin-walled structure, point out the problem of integrated impeler blades finish machining and the method to solve the chatter.Finally, through the milling experimentation of TC11 alloy lamina, the paper studied the influence of cutting force and vibration with different cutting parameter.With the datum of experimentation, it found the region of cutting stability, and made out the lobe chart under the experimentation. The paper studied the influence of the angles of ball-end milling for TC11 alloy milling, analyzed the disciplinarian of lamina’s cutting force and vibration when changing the rake angle, the first clearance angle, the second clearance angle and the helix angle,providing help for angles choosing.更多还原