This study focuses on using ultrasonic to improve the efficiency in electrical discharge machining (EDM) in gas medium. The new method is referred to as ultrasonic-assisted electrical discharge machining (UEDM). In the process of UEDM in gas, the tool electrode is a thin-walled pipe, the high-pressure gas medium is applied from inside, and the ultrasonic actuation is applied onto the workpiece. In our experiment, the workpiece material is AISI 1045 steel and the electrode material is copper. The experiment results indicate that (a) the Material Removal Rate (MRR) is increased with respect to the increase of the open voltage, the pulse duration, the amplitude of ultrasonic actuation, the discharge current, and the decrease of the wall thickness of electrode pipe; and (b) the surface roughness is increased with respect to the increase of the open voltage, the pulse duration, and the discharge current. Based on experimental results, a theoretical model to estimate the MRR and the surface roughness is developed.

Ultrasonic vibration electrical discharge machining (UEDM) in gas is proposed in this paper. It is shown that electrical discharge machining with ultrasonic aid can be achieved well in gas medium. The tool electrode is formed to be thin-walled pipe, and high pressure gas medium is supplied through it. During machining, ultrasonic vibration of workpiece can improve the machining process. The molten workpiece material can be ejected out from base body of workpiece with the aid of ultrasonic vibration and be removed/flushed out of the working gap without being reattached to the electrode. A theoretical model to estimate the material removal rate has been developed. Selecting 45# steel and copper as the workpiece material and electrode material, respectively, experiments have been carried out, the results showing that UEDM is a method with a high material removal rate (MRR). The greatest advantages of this technique are lower pollution and low electrode wear ratio.

A new method of ultrasomic vibration alectrical discharge machining (UEDM) in gas is proposed in this paper, it is shown that alectlical discharge machining (EDM) with ultrasolfic aid can be achieved well in a gas medimn. The tool electrode is formed into a tbin walled pipe, mid a high pressme gas medimn is supplied through it. During machining, ultrasonic vibration of the workpiece cml improve the machinring process. Molten workpiece material can be ejected from the base body of the workpiece with the aid of ultrasolfic vibration mul be removed/flushed out of the working gap without becoming reattached to the alectrode. Selecting #45 steel and copper as the workpiece material and alectrode material, respectively, experiments have been cm-ried out, the results showing that UEDM is a method with a high material removal rate (MRR). The greatest adwntages of this technique are lower pollution and a low electrode wear ratio.

A method for drilling holes in engineering ceramics by using a diamond tool has been developed. In this method, a drilling tool rotates with fixed abrasives. The machining mechanism of drilling based on the fracture mechanics concept is analyzed, and a new theoretical model of the material removal rate is proposed. According to this model, the material removal rate increases in accordance with the increase of the static load applied, the rotational speed of the drilling tool, and the grain size of the abrasive. Selecting 99.5% Al2O3 ceramics as the workpiece material, experiments have been carried out. The results show that diamond drilling is an effective method for machining engineering ceramics.