Calculation of the flight velocity of solid particles during an electric discharge pulse in a jet of an electrically conductive pulp

1975 ◽  
Vol 14 (3) ◽  
pp. 196-199
Author(s):  
G. A. Meerson ◽  
G. A. Kassir ◽  
E. M. Temnikov
1995 ◽  
Vol 15 (10) ◽  
pp. 1037-1041 ◽  
Author(s):  
J.G.P. Binner ◽  
P.A. Davis ◽  
J.A. Fernie ◽  
I.D. Dubovetskü

2011 ◽  
Vol 223 ◽  
pp. 950-959
Author(s):  
Ricardo Olinik ◽  
Paulo Andre de Camargo Beltrão

This paper shows a study of correlation between EDM´s parameters with the level of superficial defects development, which can lead to premature failure of die cast mold machined by EDM. The correlation of parameters was determined through experimental matrix that uses the DOE methodology (Design of Experiment). In order to evaluate the surfaces of some machined samples a stereo optical microscopy, SEM (the scanning electron microscope) and a micro hardness profile machine were used. The results show that in the worst machining condition, which is caused by association of long electric discharge pulse time-on and graphite machine-electrode, it is possible to minimize the amount of surface defects, without applying a subsequent machining process such as polishing, just using the reduced time-on´s electric discharge pulse, copper electrode and dielectric fluid with base of hydrocarbon.


2014 ◽  
Vol 778-780 ◽  
pp. 776-779 ◽  
Author(s):  
Masumi Ogawa ◽  
Kei Mine ◽  
Seiki Fuchiyama ◽  
Yasuhiro Tawa ◽  
Tomohisa Kato

In order to slice the larger size ingot toward 6 inch of silicon carbide (SiC), we are developing Multi-wire Electric Discharge Machining (EDM). To prevent wire break during slicing, we have developed the electric discharge pulse control system. So far, with 10 multi-wires, we have succeeded in slicing of 4 inch SiC balk single crystal without wire break. High quality slicing surface (e.g. small value of around 10 μm of SORI for 3 inchi wafer) was also achieved. By polishing methode, EDM-sliced wafer was estimated to have the uniform thickness of damaged layer over the entire surface. We confirmed that the wafer sliced by EDM can be processed in the later process, by grinding the 3 inch wafer. And it was confirmed that 6 inch ingot can be sliced with 10 multi-wire EDM, by slicing the boule of SiC poly crystal. For the larger diameter ingot than 4 inch, Multi-wire EDM will be practically used by the effective removal of machining chips from the machining clearance between the wire and work.


2013 ◽  
Vol 797 ◽  
pp. 362-367
Author(s):  
Manabu Iwai ◽  
Shinichi Ninomiya ◽  
Zhi Rong Zhou ◽  
Kiyoshi Suzuki

For a purpose to improve electric discharge machinability of PCD composed of coarse (25μm) diamond particles, which has been thought to be extremely difficult to EDM, in this study, a method (US-EDM) to give an ultrasonic vibration to an electrode in axial direction, flexural direction and complex direction that couples axial and flexural directions was attempted. As a result, it was found that EDM efficiency could be improved to 6 times higher (0.065mm3/min) than a standard efficiency (0.011mm3/min) obtained in machining conventional PCD (C-PCD) and the electrode wear could be reduced to 1/2 by giving vibrations to the electrode in axial direction (frequency f=28kHz, amplitude δ=18μm). Further, this method (US-EDM) was applied also to a new PCD (EC-PCD) composed of electrically conductive diamond particles. As a result, it was made clear that EDM efficiency could be improved to 0.22mm3/min. This value is equivalent to approximately 5 times higher efficiency obtained in the machining of ordinary die steel and cemented carbide materials.


2021 ◽  
Vol 106 ◽  
pp. 31-38
Author(s):  
Sovan Bhowmick ◽  
Gautam Majumdar ◽  
Asish Bandyopadhyay

Powder mixed electric discharge machining (PMEDM) is a newly developed technology in which EDM is performed by mixing electrically conductive micro or nanoparticles with dielectric fluid. The electrically conductive tiny particles when come at the gap of electrode and work piece, they will begin to create spark by the induction of electrode voltage which enhances the material removal and surface finish of the machined surface. In this paper a brief review has been done on different aspects of powder mixed electric discharge machining. It is observed that the researches are done in three main directions. Firstly, experimental studies are done to show the effect of several input process parameters on responses mainly material removal rate (MRR), surface roughness and tool wear rate. Secondly, the metallurgical characteristics of the machined surface are analyzed to measure the white layer thickness and amount of powder material inclusion onto the surface. The third one is the investigation of thermal characteristics of the tool and work pieces during the machining process. In these three sections of researches, the results of the investigations have been discussed in this review. Keywords: powder mixed electric discharge machining, metallurgical characteristics, nano particles, material removal rate, surface roughness, tool wear rate, white layer thickness, thermal characteristics


Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 861
Author(s):  
Yoshinori Matsuda ◽  
Kunihiko Shimizu ◽  
Takahiro Sonoda ◽  
Yoshihiro Takikawa

An electrostatic apparatus was developed to control weeds and houseflies emerging from ground soil in a greenhouse simultaneously. Identical iron plates were placed in parallel at a defined interval and fixed in an iron frame. Two sets of fixed iron plates were used, one for weed control and one for fly control. For weed control, all of the iron plates were negatively charged, and negative charges accumulated on the plates were released to weed shoots through arc discharge. Houseflies were introduced into the space between the negatively charged and grounded plates, then subjected to arc discharge from the charged plates. Both plant shoots and adult houseflies are electrically conductive; thus, they were killed by discharge-exposure in the electric field between the charged iron plate and the ground soil, and between the charged and grounded plates, respectively. In practical use, these two devices were assembled as a two-level apparatus for simultaneous control of both targets. Several apparatuses were linked together, which increased the total electricity charge on the plates and produced a stronger discharge force sufficient to kill all targets. Thus, this study provides an electrostatics-based pest-control method for pesticide-independent greenhouse farming.


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