1991 Fiscal Year Final Research Report Summary
Spectroscopic study on Metal Vapor and Mechanism of Vaporization in Plasma Refining
| Project/Area Number |
02453053
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属精錬・金属化学
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| Research Institution | Hokkaido University |
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Principal Investigator |
ISHII Kuniyoshi Hokkaido Univ. Fac. of Eng. Professor, 工学部, 教授 (00001214)
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| Co-Investigator(Kenkyū-buntansha) |
KATSUMI Miho Hokkaido Univ. Fac. of Eng. Research Associate, 工学部, 助手 (70214351)
KASHIWAYA Yoshiaki Hokkaido Univ. Fac. of Eng. Research Associate, 工学部, 助手 (10169435)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Plasma Spectrometry / Ar Arc Plasma / Multichannel Spectrophotometer / Plasma Melting of Metal / Vaporization of Metal / Metal Vapor Density / Temperature of Plasma |
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| Research Abstract |
Recentry, many attention is focused on high energy implantation in material processing because plasma is clean and easy controllable source, and the action of radical reactant is expected. For the fundamental study of material processing using thermal plasma, the distribution of temperature and metal vapor density in Ar plasma were spectroscopically investigated in the present research project.
Spectroscopic apparatus was newly developed and composed of a computerized monochromator having high resolution, multichannel detector, and double focused movable collimator. The measured intensity of spectra was converted to the true values along center line of plasma column by using inverse Abel transformation. The temperature was obtained by Boltzmann plot using the true values of Ar spectral line intensity and the density of metal Vapor in plasma was decided from the intensity of Fe and Ti line spectrum using Saha's equation.
(1) The temperature of Ar plasma was from 3500 to 6500K, and lowered
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with far from the center axis of plasma column and also approaching button surface. The temperature of metal vapor plasma was lower about 500K than that of Ar plasma.
(2) The intensity of Fe and Ti spectra increased with decrease of electrode distance, but decreased with increasing flowrate of Ar. The spectrum of metal vapor near the button surface was observed strongest over a concentric circle of about 7 mm radius which the center was set on the anode spot. The fact indicates that vaporization of metal takes place at the location.
(3) In the case of H2 addition, Ar plasma became to shrink and the temperature decreased. On the other hand, the amount of vaporized metal increased to about 2 times of ordinary Ar plasma. It suggests that some sequence of enhanced vaporization operates in the metal button melted by the plasma containing H_2.
(4) It was found that the major carrier of electron near surface of metal button was metal plasma. The transition boundary from Ar plasma to metal plasma became apart from surface of button in Ar-H_2 plasma because of large metal vapor density. Less
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