研究了工作介质的氧化特性对钛合金电火花加工电极绝对损耗、相对损耗率及电极表面微观形貌的影响规律。结果表明,具有氧化特性的工作介质可在加工过程中使电极氧化,并在电极表面形成一层氧化保护膜,减小带电粒子对基体的轰击,从而降低电极绝对损耗;介质的氧化特性也会对钛合金电火花加工效率和排屑产生影响,使电极相对损耗率呈先减小、后增长、再趋于稳定的趋势;极间氧气增多能增大放电爆炸力,使电极表面微裂纹和气孔数量增多;工作介质存在一个最佳氧化性能,可使钛合金加工的电极损耗达到最佳状态。

This paper has studied how the oxidbillity of dielectric will influence the processability of titanium alloy EDM,such as electrode absolute wear, electrode relative wearing rate and electrode surface microsmic topography. The result shows that dielectrics of oxidbillity can oxidize the electrode during processing and form an oxide layer on it which can reduce the bump of electronics to the electrode,thereby its absolute wear is lower. The oxidbillity of dielectric will affect the material removal rate and the expulsion of elaboration product in titanium alloy EDM to make the electrode relative wearing rate increase after decrease,and then to stability. The more oxygen there is in the discharge gap,the bigger the explosive power will be,which will produce more microcracks and gas holes on electrode surface. There is an optimal range for the oxidbillity of dielectric to make the electrode wear of titanium alloy EDM achieve better machining effect.

侧铣式高速电弧放电加工利用电极侧面放电蚀除工件材料,能加工复杂的型腔、沟槽及直纹面等。为了探索这种新型电弧放电加工的工艺特性,探讨了峰值电流、脉宽和冲液压力等条件对工件材料去除率和相对电极损耗率的影响。实验结果表明:提高冲液压力和峰值电流均能增大工件材料去除率;相对电极损耗率随冲液压力的提高而增大,随峰值电流的提高而减小。在一定范围内,工件材料去除率随脉宽的提高而增大,相对电极损耗率随脉宽的提高而减小。

Flank milling blasting erosion arc machining mainly uses the flank of electrode to remove the material. It can be applied in machining of concaves with complex surfaces ,and slots as well. Machining experiments were conducted to explore the machining performance of flank milling blasting erosion arc machining under different inlet pressures ,peak currents and pulse durations. The experimental results show that higher inlet pressure and peak current could improve the material removal rate correspondingly. Tool wear ratio would be amplified with the increasing of the inlet pressure,and reduced with the increasing of peak current. Increasing the pulse duration can reduce tool wear ratio,but the material removal rate increases within a certain range.

提出了一种超高效电火花电弧复合铣削镍基高温合金Inconel 718的加工方法,构建了一种新型大功率电源,主要由高压脉冲电源和低压大功率直流电源组成。在冲液和电极旋转的作用下得到了非连续电弧,材料去除率可达13 421 mm3/min,相对电极损耗率可达1.71%。进行了复合加工和电火花加工的对比实验研究,分析了电极转速对材料去除率和相对电极损耗率的影响,并对加工表面特性进行了研究。

This paper proposed a high efficient combined machining of electrical discharge machining and arc machining for machining Inconel 718. The proposed power supply comprised a pulse generator with high voltage and a DC power source with high current. Benefiting from efficient flushing and electrode rotation,the noncontinuous arc was yielded,and the maximum material removal rate (MRR) achieved 13 421 mm3/min with a relative electrode wear ratio (REWR) of 1.71 %. Comparison experiments were conducted to reveal the differences between EDM and compound machining. And the effects of rotation speed on MRR and REWR were investigated. Surface integrity was also studied.

研究了水介质电导率对钛合金的电火花加工效率、电极相对损耗率和表面粗糙度的影响。试验结果表明，随着电导率增大，击穿电压不断减小，放电间隙和漏电流不断增大。电导率增长初期，放电间隙的增大将使加工效率上升，但随着消耗于放电通道和电解上的能量增多，加工效率有所下降：电极相对损耗率和表面粗糙度值都随着电导率的增长呈上升趋势。水介质存在一个最佳电导率69μs／cm．使钛合金电火花加工综合效果最优。

Dielectrics of different conductivities have been studied in EDM titanium alloy of to dis-cuss the influence of conductivity on material removal rate (MRR), electrode relative wearing rate (ERW) and surface roughness. The results show that the conductivity is the bigger, the break-over volt-age is the smaller and the discharge gap and drain current are the larger. In the initial stage of conduc-tivity increasing, MRR rises with the discharge gap wider. When there is more energy wasted in the discharge gap and electrolysis, MRR begins to decrease. Both EWR and Ra go up with the growth of conductivity. When the conductivity of water is 69 μS/cm, we can get the best machining effect in tita-nium alloy EDM.

提出了放电诱导可控烧蚀及电火花修整成形加工方法，通过试验研究了电参数和非电参数对加工的影响。结果表明：该加工方法适合采用正极性加工；材料蚀除率受脉宽、脉间、低压电流、气体通断时间等参数的影响较大，受液位高度和电极壁厚的影响较小；电极损耗率受上述参数的影响均较小，且保持在极低的水平。通过优化参数选取，与常规水中加工实验对比表明：放电诱导可控烧蚀及电火花修整成形加工的材料蚀除率是常规水中不通氧加工的8．81倍．而电极相对损耗率只有其25．5％。

A new method called forming processing by controllable spark-induced combustion and EDM finishing is proposed. Experimental researches are carried out to realize the effect of basic operating parameters such as electrical and non-electrical parameters on machining performance. The result shows that it is suitable for positive polarity machining, and MMR is greatly influenced by these parameters such as pulse width, pulse interval, low-voltage current, and gas-off time and so on, and less affected by liquid height and electrode wall thickness. TWR is less affected by these parameters above-mentioned and remained at low levels. Finally compared with conventional machining with the optimization parameters, the results show that the ablation processing MRR is 8.81 times than conventional processing and TWR is only its 25.5%.