Apparatus for production of metal powder according water atomizing method
AssigneesHitachi, Ltd., Hitachi Metals, Ltd.
InventorsAkira Okayama, Hisashi Ando, Ko Soeno, Hisasuke Takeuchi, Atsuya Kamada
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Abstract
This invention relates to an apparatus for production of metal powders of a low oxygen content, which are preferred as raw material powders for sintered bodies of a high toughness, according to the water atomizing method. More specifically, when a molten metal is sprayed in a limited space with use of a liquid crystal medium and cooled promptly, a metal powder results of a good moldability which has an oxygen content corresponding to 1/2 or less of the oxygen contents of metal powders prepared by conventional apparatuses and which is excellent in the size uniformity.
Claims26
An apparatus for production of metal powders comprising:
- a molten metal tank,
- molten metal nozzle means which is communicated with the tank and through which molten metal passes,
- annular liquid spray means surrounding the molten metal nozzle for injecting cooling liquid into said molten metal and thereby finely dividing said molten metal,
- a granulation chamber guide through which atomized metal particles coming from the molten metal nozzle pass, and
- a water tank disposed under the chamber guide with a lower end of said guide being opened into water contained in the water tank,
- wherein said guide is dimensioned to ensure violent movement of the finely divided metal and liquid in said guide so that vapor film of said liquid on the surfaces of said finely divided metal is promptly destroyed and a fresh portion of said liquid is contacted with the surfaces of said finely divided metal.
An apparatus for production of metal powders comprising:
- a molten metal tank,
- a molten metal nozzle which is communicated with the tank and through which molten metal passes,
- a liquid spray nozzle surrounding the molten metal nozzle,
- a non-oxidizing gas-projecting nozzle positioned between the molten metal nozzle and the liquid spray nozzle,
- a granulation chamber guide of limited cross-sectional area to violently mix the metal, liquid and gas coming from the molten metal nozzle, the liquid spray nozzle and the gas-projecting nozzle, respectively, and disposed to introduce the same into stagnant water in the state devoid of air, and
- a stagnant water tank disposed under the chamber guide with the lower end of said guide being immersed into the stagnant water in the tank.
Apparatus for producing metal powders comprising:
- molten metal spray means having an end portion from which molten metal received from molten metal supply means is sprayed, and
- liquid spray means arranged to direct a liquid spray which intercepts a molten metal spray from said molten metal spray means within a converging portion of an atomizing chamber which surrounds said end portion.
Dependencies are inferred from the claim text.