Ultrasonic Assisted Electronic-Discharging by Using Ceramic Fiber Punch for Electrode

碳化硅纤维的强度高于硬质钢，其刚度大致相同。因此，单根碳化硅纤维是超细冲孔的良好候选材料。超细穿孔在连续加工过程中必须在无润滑剂的情况下进行。陶瓷纤维的热稳定性得到保证，并且通过形成不透氧的二氧化硅层来稳定SiC抗氧化。此外，陶瓷在化学上对金属反应较弱。因此，陶瓷纤维冲头期望有较长的刀具寿命。本研究采用的纤维冲孔制造方法是通过抛光和电解，称为FPBE工艺。超细穿孔系统由个人电脑控制。计算机通过D/ a转换器将控制信号发送给(1)压电驱动器，压电驱动器的电源，驱动冲床，(2)步进电机的驱动单元，该驱动器在通过a /D转换器从(3)测量冲床力的称重传感器和(4)测量冲床行程的位移传感器获取数据的同时，对穿孔箔进行绕组。通过压电驱动器电压信号的变化来控制冲床速度。金属箔的进给是由卷绕滚筒的直径和步进电机的转速来设定的。用于测量冲床行程的涡流式位移传感器的最大测量长度为1mm，并且由于非接触式而不加在冲床负载测量中。用于测量冲孔载荷的测压元件的最大载荷为5n。作用在测压元件上的力与冲孔行程的关系是在非切割冲孔和穿刺冲孔时测量的，而净冲孔载荷是由这两种载荷的差得到的。选择厚度为17的商用纯铝箔（A1100-H）、厚度为15 um的铍铜箔（25合金-1/ 4h）和厚度为8 pm的不锈钢箔（SUS304-H）作为穿孔材料。不锈钢箔是一种高强度材料，铍铜具有良好的变形性，可用作高强度导电弹簧。对穿孔的观察表明，铝和铍铜的大部分剪切表面是光滑的，而不锈钢的切割表面由66%的光滑和33%的无毛刺的断裂表面积组成。用于铝箔和铍铜箔的冲床经过1000次敲击后，没有出现裂纹、磨损和卡扣现象，而用于不锈钢的冲床没有出现磨损，只有出现裂纹。少

The strength of the SiC fiber is higher than hard steels and its rigidity is approximately the same. Therefore, a single SiC fiber is a good candidate for an ultrafine punch. The ultrafine piercing must be conducted without lubricant in continuous processes. Thermal stability of the ceramic fiber is guaranteed, and SiC is stabilized against oxidation by forming an oxygen-impervious silica layer. Besides, ceramics are chemically less reactive to metals. Therefore, a long tool life is expected for ceramics fiber punches. The fiber punch making method employed in our study, by buffing and electrolysis, referred as FPBE process. The ultrafine piercing system is controlled by a personal computer. The computer sends control signals through a D/A converter to (1) a piezoelectric driver, the power source of the piezoelectric actuator, that moves the punch, and (2) the driver unit of the stepping motor that wind the pierced foil while obtaining data through an A/D converter from (3) a load cell … More measuring punch force, and (4) a displacement sensor measuring the punch stroke.Punch speed is controlled by the change of the piezoelectric driver voltage signal. Metallic foil feed is set by the diameter of the winding drum and the rotation of the stepping motor. The eddy current type displacement sensor for measuring the punch stroke has a maximum measuring length of 1 mm, and does not add up to the punch load measurement because of non-contact type. The load cell for measuring punch loads has the maximum load of 5 N. The forces acting on the load cell vs. punch stroke are measured for both the non-cutting and piercing strokes and the net punch load is obtained from the difference of the two loads. Commercial pure aluminum foil (A1100-H) of 17 thickness, beryllium copper foil (25 alloy-1/4H) of 15 um thickness and stainless steel foil (SUS304-H) of 8 p.m thickness were selected as materials to be pierced. The stainless steel foil is a high strength material and the beryllium copper has a good deformability and can be used as high strength conductive springs. Observation of the pierced hole shows that most of the sheared surface of the aluminum and beryllium copper is a smooth, whereas that of the stainless steel is composed of 66 % smooth and 33 % fractured surface area without burr. After 1000 taps, the punch used for the aluminum foil and beryllium copper foil had no cracks, wear or seizure whereas the stainless steel showed no wear but cracks. Less