TC4钛合金超声振动高速走丝电火花线切割复合加工的研究

发布时间：2018-05-03 02:05

本文选题：TC4钛合金 + 高速走丝电火花线切割加工　；参考：《中北大学》2017年硕士论文

【摘要】：电火花线切割加工是利用电极丝与工件之间的间歇性脉冲放电产生的能量对导电材料进行去除的特种加工方法。由于其可加工各种具有复杂结构、特殊要求的工件和难加工材料,因此被广泛的应用在航天、电子、民用等工业领域。但随着科学技术的不断进步,对电火花线切割加工的要求也越来越高。将超声加工与电火花线切割加工结合起来可以有效地提高加工效率、表面质量,被国内外许多专家学者关注。目前的研究大多是把超声振动装置作用在电极丝上,但存在许多缺点,比如:会影响到电极丝的加工精度;在锥度加工时,超声振动装置很难作用在电极丝上等,因此本文考虑将超声振动装置作用在工件上,进行试验研究。本文首先采用类比的方法对工件超声振动高速走丝电火花线切割复合加工进行可行性分析,接着对超声振动装置进行设计,主要对工件和装置夹具进行设计,并将设计加工好的超声振动装置安装在DK-7720Z高速走丝电火花线切割机床上进行调试、校验。其次进行了TC4钛合金常规高速走丝电火花线切割加工的试验研究,分析了电参数,主要是电流、脉冲宽度、脉冲间隔对表面粗糙度、切割速度的影响顺序和上述二个工艺指标的最优参数组。再次对TC4钛合金进行工件超声振动高速走丝电火花线切割复合加工,采用极差分析、方差分析、信噪比分析对试验数据进行了研究。接着采用对比试验的方法,在相同工艺条件下,分别研究电极丝切割方向与超声振动方向水平、垂直及工件超声振动与无超声振动对上述两个工艺指标的影响,分析发现:将超声振动作用在工件上以后,表面粗糙度明显降低,且电极丝切割方向与超声振动方向水平可以获得更好的表面粗糙度,而在切割速度方面,仅在某些电参数下明显提高。然后就超声振动的引入对高速走丝电火花线切割加工工况的改善进行了四个方面的分析。接着将电参数保持不变,改变超声频率和超声振幅进行了工件超声振动高速走丝电火花线切割复合加工试验,发现只有加工能量和加工时间匹配得当,才可以既降低了表面粗糙度又提高了切割速度。最后基于BP神经网络对工件超声振动高速走丝电火花线切割复合加工进行工艺预测模型的建立,通过仿真值与实际值的对比,验证了工艺预测模型具有强大的学习和泛化能力。
[Abstract]:WEDM is a special processing method for the removal of conductive materials by the energy generated by intermittent pulse discharge between the electrode wire and the workpiece. It is widely used in aerospace, electronic, civil and other industrial fields because of its processing of various complex structures, special requirements and hard working materials. With the continuous progress of science and technology, the demand for EDM machining is becoming higher and higher. Combining ultrasonic machining with EDM can effectively improve the machining efficiency and surface quality, which is concerned by many experts and scholars at home and abroad. Many shortcomings, such as: it will affect the machining precision of electrode wire; in taper machining, the ultrasonic vibration device is difficult to function on the electrode wire. Therefore, this paper consider the ultrasonic vibration device to act on the workpiece and carry out the experimental research. Firstly, the method of analogy is used to the ultrasonic vibration high speed wire EDM composite machining. The feasibility analysis is carried out, then the ultrasonic vibration device is designed, the main workpiece and device fixture are designed, and the designed ultrasonic vibration device is installed on the DK-7720Z high speed wire EDM machine tool, and the test is done. Secondly, the test of the TC4 titanium alloy conventional high speed wire EDM machining is carried out. The analysis of electrical parameters, such as electric parameters, mainly current, pulse width, pulse interval on surface roughness, cutting speed, and the best parameters of the above two technical indexes. The ultrasonic vibration high-speed wire EDM composite machining of TC4 titanium alloy was processed again, and the difference analysis, analysis of variance, and the signal to noise ratio were analyzed. The experimental data are studied. Then, under the same technological conditions, the influence of the direction of electrode wire cutting and the direction of ultrasonic vibration, the ultrasonic vibration of the workpiece and the non ultrasonic vibration on the above two technical indexes are studied under the same technological conditions. The results are as follows: after the ultrasonic vibration is acted on the workpiece, the surface is rough. A better surface roughness can be obtained by the direction of wire cutting and the direction of ultrasonic vibration. In the cutting speed, only some electrical parameters are improved obviously. Then four aspects of the improvement of the working conditions of high speed wire EDM are analyzed with the introduction of ultrasonic vibration. The ultrasonic vibration and ultrasonic vibration of the workpiece are changed and the ultrasonic vibration and ultrasonic vibration of the workpiece are changed. It is found that the surface roughness and the cutting speed can be improved only if the processing energy and the processing time match properly. Finally, the ultrasonic vibration of the workpiece is high speed wire based on the BP neural network. The process prediction model of spark wire cutting is established. Through the comparison of the simulation value and the actual value, it is proved that the process prediction model has a powerful learning and generalization ability.

【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG663;TG484

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