Study of Machine Characteristics During Rotary EDM Machining using Tools Made of Aluminium Alloy 6061

Electro discharge machining (EDM) is an unconventional machining process that uses spark energy to remove material from the workpiece. EDM process is extensively being used in die/mould making industries, automobile industry, aerospace industry etc. for generating complex and intricate shape on hard material. Numbers of research works have been carried out using EDM process in order to improve the performance. Further, different variant of EDM process like dry EDM, orbital EDM, powder mixed EDM, ultrasonic assisted EDM and rotary EDM etc. have also been studied. Rotary EDM process is very promising process that helps to improve surface finish, overcut as well as out of roundness. In the present paper, a extensive review has been presented on rotary EDM process. Significance of several input parameters has been observed on output characteristics like overcut and out of roundness.

Comparison of Conventional, Powder Mixed, and Ultrasonic Assisted EDM by Phenomenological Reasoning

Electro-discharge machining (EDM) is widely used in industries for machining complex shapes and difficult-to-machine materials that are conductive. In the present work, performance of conventional die-sinking EDM process is compared with powder mixed and ultrasonic assisted processes in machining of D3 steel. Using different sets of parameters for rough and finish ED machining, material removal rate and surface roughness are obtained experimentally. The influences of the parameters on material removal rate and surface roughness are presented on the basis of phenomenological reasoning. The results are discussed and suitable recommendations for the practitioners are included.

EDM Machinabilities of EC-PCD Using Ultrasonic Assisted EDM and Bipolar Pulse Current EDM

In order to achieve a high efficient and high quality EDM of PCD, the authors have developed a new PCD having superior electrical conductivity by using boron diamond as a source material. On the other hand they applied a method to give ultrasonic vibrations to the electrode, and have made it clear that even the standard PCD could be machined at the similar level of efficiency to the cases of EDMing die steels and cemented carbides. With a purpose to obtain a good surface roughness on the PCD at high efficiency, various EDM conditions and methods were compared in this paper. Firstly, influence of discharge duration time was examined, and it was found that a shorter pulse duration time as te=0.5μs showed high efficiency and smaller electrode wear rate. Secondary, influence of bipolar pulse current method was examined, and it was found that the method effected higher efficiency but rather large amount of electrode wear resulted. Thirdly, ultrasonic assisted EDM was conducted, and it was found that the method showed superior result regarding efficiency and wear rate on both standard PCD and EC-PCD. A combination use of ultrasonic assisted and bipolar pulse current EDM methods was also attempted in this research. On the contrary to the expectation, efficiency and electrode wear rate became worse in EDM of standard and EC-PCD in comparison with other methods tested before.