TC4钛合金工件超声振动电火花复合加工试验研究

发布时间：2018-05-12 08:50

本文选题：电火花加工 + 水平超声振动　；参考：《中北大学》2016年硕士论文

【摘要】：TC4钛合金由于比强度高、密度小,机械性能好,韧性和抗蚀能力强等优点被广泛用于各个领域。本试验主要的目的就是如何能够高效地加工TC4钛合金,使其具有较快的加工速度、较好的表面精度和较少的电极损耗。首先分析常规机加工、常规电火花加工和超声电火花复合加工的可行性,由于TC4钛合金的导热性差、黏性大,切削加工性也较差,常规机加工时常产生较大的形变。而电火花加工只与材料的热学特性有关,属于非接触式加工,无宏观作用力,无明显的划痕,但是其加工效率低,成形质量较差,但附加超声振动后,上述不足可以改善。其次,在正负极性条件下,对TC4钛合金进行常规电火花试验,分析电参数是如何影响上述三个工艺指标,并分别获得在粗加工及精加工需求下,最佳的电参数水平组合,得到正极性加工的表面粗糙度较好,负极性加工材料去除率较高的结论。最后,由于本试验的重中之重是表面粗糙度,故选择在常规电火花正极性条件下,设计了声振系统及其整体的固定安装夹具,分别在TC4钛合金工件上加载水平和竖直方向的超声波振动,各设计了两种加工方案并进行对比。其一是在正极性加工的九组参数组合基础上,附加确定频率、振幅的超声,分析对比了两种方式的超声加载对指标的影响,结论是:对于电极损耗,二者影响几无差别,但水平超声可以获得较好的表面粗糙度,而竖直超声可以获得较快的加工速度;另一种是在精加工中最优参数组的基础上,附加振幅变化的超声波,探讨了超声振幅对火花放电的影响,得到一定范围内,附加水平超声的加工中,振幅增大可以使放电点左右运动,改善表面质量,而附加竖直超声的加工中,振幅增大可使放电点上下移动,加快放电通道建立时间,提高加工效率。
[Abstract]:TC4 titanium alloy has been widely used in various fields because of its high strength, small density, good mechanical properties, strong toughness and strong corrosion resistance. The main purpose of this test is how to efficiently process TC4 titanium alloy to make it have faster processing speed, better surface precision and less electrode loss. The feasibility of conventional EDM and ultrasonic EDM composite machining is feasible. Due to the poor thermal conductivity, high viscosity and poor machinability of TC4 titanium alloy, conventional machining often produces large deformation. EDM is only related to the thermal properties of materials, which belongs to non-contact machining, without macro force and no obvious scratch, but it has no obvious scratches. The processing efficiency is low and the forming quality is poor, but the above defects can be improved after the additional ultrasonic vibration. Secondly, under the positive and negative polarity conditions, the conventional EDM test is carried out on the TC4 titanium alloy. How the electrical parameters affect the above three technical indexes is analyzed, and the best combination of electrical parameters is obtained under the demand of rough adding and finishing, and the optimum combination of electrical parameters is obtained. To the conclusion that the surface roughness of the positive machining is better and the material removal rate of the negative machining is high. Finally, because the weight of the test is the surface roughness, the sound vibration system and its fixed installation fixture are designed under the normal electric spark positive condition, and the horizontal and vertical load are loaded on the TC4 titanium alloy workpiece respectively. In the direction of ultrasonic vibration, two kinds of processing schemes are designed and compared. One is on the basis of nine groups of parameters combination of the positive polar processing, and on the basis of the combination of the nine parameters of the positive polar processing, the influence of the ultrasonic loading on the two modes is analyzed and compared. The conclusion is that the influence of the two is indifferent to the electrode loss, but the horizontal ultrasonic is available. In order to obtain better surface roughness, the vertical ultrasonic can obtain faster processing speed, and on the basis of the optimal array in fine processing, the ultrasonic amplitude is attached to the ultrasonic amplitude, and the effect of ultrasonic amplitude on spark discharge is discussed. In a certain range, the increase of amplitude can make the discharge point in the processing of additional horizontal ultrasonic. In the processing of vertical ultrasonic, the increase of amplitude can make the discharge point move up and down, speed up the time of setting up the discharge channel and improve the processing efficiency.

【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG666

【相似文献】