Authors: Li Li, Guang Ming Yuan, Zong Wei Niu, Rong Guo Hou
Abstract: Sintered NdFeB permanent magnet is widely used in many areas because of its excellent magnet property. In this study, the machining parameters of electrical discharge machining (EDM) are varied to study the effects of electrical discharge energy on material removal rate and surface roughness of NdFeB magnet. Moreover, the micro-cracks on the machined surface induced by EDM are also examined. The experimental results reveal that the MRR increases with the electrical discharge energy. The number of surface cracks on the machined surface increases with the enhancement of discharge energy Thus, using EDM process to machine sintered NdFeB magnet depends on setting the machining parameters to prevent surface crack.
711
Authors: Ying Ping Qian, Ju Hua Huang, Xi Zhi Zhou, Masanori Kunieda
Abstract: In this paper, the attempt was made to study dry WEDG (Wire Electrical Discharge Grinding), the differences between dry WEDG and wet WEDG, especially the rods appearance and material removal speed and surface roughness were studied experimentally, the results are as follow: (1) The shape especially the symmetry of the rods fabricated with WEDG using kerosene as dielectric fluid is better than that of dry WEDG only using pure air as dielectric. (2) The material removal speed is obviously higher in wet WEDG than that in dry WEDG. (3) The surface roughness of the rods fabricated with wet WEDG is lower than that with dry WEDG;.(4) The wet WEDG can be used in the roughness machining to improve the speed, and the dry WEDG can be used in the finishing machining to advance the surface quality.
2146
Authors: Hideki Yamada, Satarou Yamaguchi, Norimasa Yamamoto, Tomohisa Kato
Abstract: A new method based on electric discharge machining (EDM) was developed for cutting a silicon carbide (SiC) ingot. The EDM method is a very useful technique to cut hard materials like SiC. By cutting with the EDM method, kerf loss and roughness of sample are generally smaller than those obtained by cutting with a diamond saw. Moreover, the warpage is smaller than that by the diamond saw cutting, and the cutting speed can be 10 times faster than that of the diamond saw at the present time. We used wires of 50 mm and 100 mm diameters in the experiments, and the experimental results of the cutting speed and the kerf losses are presented. The kerf loss of the 50 mm wire is less than 100 mm, and the cutting speed is about 0.8 mm/min for the thickness of a 6 mm SiC ingot. If we can maintain the cutting speed, the slicing time of a 2 inches diameter ingot would be about seven hours.
861
Abstract: The paper deals with the experiments realized by means of cutting tool with linear cutting edge not parallel with the axis of the workpiece in order to be observed the suitable values of surface roughness characteristics in dependency on the feed and cutting speed. During experiments were machined three types of steels. Acquired data were statistical processed by regression analysis. The results of the measurements show that the investigated cutting tool enables to secure the same values of surface profile characteristics of steels as a classical cutting tool at finishing with the significant increase of the feed per revolution. It directly influences length of the technological operation time which is several times shortened and so the machining productivity can increase.
352
Authors: T. Muthuramalingam, B. Mohan
Abstract: In automobile and aeronautical industries, complex moulds and dies is produced by Electrical Discharge Machining process. The surface finish is determined by the crater volume in EDM process. The amount of crater volume is influenced by the amount and distribution of discharge energy. The discharge energy is directly proportional to the average discharge current. This amount of current is determined by the duration of discharging effect. This study deals about evaluating the performance of iso current pulse generator on machining characteristics in EDM. Due to its ability of reducing stochastic nature in EDM process, iso pulse generator could produce better surface finish than conventional transistor pulse train generator with higher material removal rate.
380
