| Autor: |
Revaz, B., Witz, G., Flükiger, R. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 12/1/2005, Vol. 98 Issue 11, p113305, 6p, 2 Diagrams, 1 Chart, 4 Graphs |
| Abstrakt: |
The properties of the plasma channel at the cathode surface in a liquid discharge have been studied by means of temperature measurements and heat transfer numerical analysis. The studied discharge (current: 5 A; duration: 100 μs; gap: 10 μm) is typical of electrical discharge machining (EDM) in the semifinishing operation. The temperature information is obtained from two independent experiments: (1) microthermocouples patterned on the cathode, close to the discharge have been used to record the temperature variation caused by a single discharge with a high local resolution and large bandwidth; (2) the geometry of the resolidified layer, which gives the maximum extension of the melting point temperature isotherm, has been measured. These temperature data have then been compared to numerical simulation using inverse calculations allowing the experimental determination of two fundamental quantities of the discharge cathode interaction: (1) the power fraction transferred from the discharge to the sample, which was found to be close to 10% and (2) the exponent n of the power law expansion of the plasma channel rplasma∝tn, which is n=0.2. The validity of the present analysis relies on the fact that the experimental temperature information is obtained for different values of the parameter rplasma/t02, where t02 is the characteristic time of the experiment. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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