US3533136A - Apparatus for producing metal powder - Google Patents
Apparatus for producing metal powder Download PDFInfo
- Publication number
- US3533136A US3533136A US645318A US3533136DA US3533136A US 3533136 A US3533136 A US 3533136A US 645318 A US645318 A US 645318A US 3533136D A US3533136D A US 3533136DA US 3533136 A US3533136 A US 3533136A
- Authority
- US
- United States
- Prior art keywords
- hearth
- metal
- vessel
- atomizing
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
Definitions
- a water vessel is mounted on the vessel beneath the hearth for containing a reservoir of recirculating water to directly cool the underside of the metal hearth whereby the top surface of the metal hearth is cooled by conduction.
- the atomizer sprays molten metal droplets into the interior of the atomizing vessel against the top surface of the metal hearth to rapidly quench the droplets.
- This invention relates in general to a method and apparatus for producing prealloyed metal powder, and it more particularly relates to a method and apparatus for atomizing and then rapidly quenching molten metal to form prealloyed metal powder for subsequent consolidation into solid stock.
- alloys have been successfully made by a rapid quench atomizing technique followed by a consolidation of the powders thus formed into solid stock.
- Molten metal was subjected to a blast of gas inert to the metal to produce a finely-divided spray of metal droplets which were directed into an atomizing chamber to rapidly quench the droplets, thereby eliminating sintering or agglomeration of the powders.
- a water-reservoir in the atomizing chamber fully quenched and collected the particles.
- Such a technique was not entirely satisfactory, because the stream of gas and hot metal droplets violently agitated the water reservoir within the vessel, whereby unwanted oxide films were produced on the powder surfaces.
- the droplets were sprayed into a tall atomizing vessel, having a height of at least twenty feet, so that the falling droplets released their heat to the surrounding atmosphere before reaching the bottom of the vessel.
- the tall vessels were difficult to purge with the inert gas prior to atomizing the molten metal, and oxide-free powders could only be obtained by using large volumes of costly inert gases. Therefore, it would be desirable to have an atomizing vessel which retains the relatively small size of the water-reservoir type of vessel and which completely eliminates water or other oxidizing materials from the powder collection area.
- the principal object of the present invention is to provide a new and improved method and apparatus for producing prealloyed metal powder.
- Another object of the present invention is to provide an inexpensive and efficient method and apparatus for rapdily quenching atomized metal droplets without the use of water or other fluids in the powder collection area and without the use of unreasonably tall chambers.
- an atomizing vessel having a droplet- 3,533,136 Patented Oct. 13, 1970 quenching metal health, which has its underside directly cooled so that its top surface is thereby cooled by conduction.
- a Water vessel containing a reservoir of recirculating water is mounted on the vessel beneath the hearth for cooling the underside of the hearth, which forms the top wall of the water vessel.
- the prealloyed metal powder produced by the method and apparatus of the present invention is substantially oxide free as compared to the prealloyed metal powder produced by the prior art water-reservoir vessel. Since no water is present in the atomizing vessel of the present invention, the vessel may be constructed of inexpensive mild steel instead of stainless steel as used in the prior art water-reservoir vessels.
- FIG. 1 is a front elevational view in vertical cross section of an apparatus for producing metal powder in accordance with the present invention.
- FIG. 2 is a front elevational view in vertical cross section of another apparatus for producing metal powder in accordance with the present invention.
- the apparatus 10 comprises a vessel 12 having an atomizing chamber 13, a gas atomizing nozzle and tundish assembly 14 mounted on the top of the vessel 12, a water-cooled metal hearth 16 at the bottom of the chamber 13, and a water-reservoir chamber 18 disposed beneath the hearth 16 within the vessel 12 for cooling the underside of the hearth 16.
- a high pressure jet of inert gas atomizes a stream of liquid metal flowing from the tundish assembly 14 and directs the metal droplets into the atomizing chamber 13 to splatter the droplets against the water-cooled metal hearth 16 at the bottom of the vessel 12 whereby the droplets are rapidly quenched.
- Most of the solidified particles are blown free of the hearth and are readily removed from the chamber 13.
- the remainder generally not more than 25-30% of the product, is recovered as a solid splatter layer which is easily crushed into a fine powder.
- the products can then be combined and the fine atomized metal powder consolidated by a hot working process.
- the water-cooled hearth 16 is disposed at the bottom of the atomizing chamber 13 and is composed of a good-conducting material, such as copper.
- the hearth 16 is connected to the side walls of the vessel 12 in sealable engagement therewith to form the bottom wall of the atomizing chamber 13 and the top wall of the water-reservoir chamber 18.
- An opened-top vessel 20 is disposed within the chamber 18 in close proximity to the underside of the hearth 16 for containing a continuous supply of recirculating Water from a pump (not shown) via a water inlet pipe 22 extending through an opening in a bottom wall 24 of the vessel 12 and. an opening in the bottom wall 25 of the water vessel 20.
- the vessel 20 is disposed in a spaced-apart relationship above the bottom wall 24 so that the recirculating water in the vessel 20 overflows therefrom and flows downwardly under its bottom wall 25 into a pair of water outlet pipes 26 extending through respective openings in the bottom wall 24.
- the recirculating water flows from the outlet pipes 26 to the pump for recirculation to the inlet pipe 22.
- the water is pumped into the chamber 18 under a sufficient pressure to maintain the chamber in a comlpetely filled condition so that the recirculating water contacts the underside of the hearth 16.
- the tundish assembly 14 is externally mounted on a detachably-mounted cover 28 of the vessel 12 over a centrally-disposed opening 31 in the cover 28 to permit the stream of gas and atomized metal droplets from the assembly 14 to enter the atomizing chamber 13.
- the assembly 14 comprises a housing 33 mounted on the exterior of the cover 28 of the vessel 12 over the opening 31, a tundish 35 supported by the housing 33, a refractory lined nozzle or cone 37 mounted at the bottom of the tundish 35 and connected in fluid communication therewith, and a gas inlet pipe 39 for conveying gas inert to the metal to be atomized from a source of inert gas under pressure (not shown) to the interior of the housing 33.
- the gas inlet pipe 39 is connected in fluid communication with a chamber 41 within the housing 33.
- the inert gas is directed from the chamber 41 to the atomizing chamber *13 by means of a collar 43 surrounding the nozzle 37 within the chamber 41 and threaded into a threaded shoulder portion 45 forming part of the housing 33.
- the collar 43 is provided with a bevel-cut inner wall portion 47 at the lower portion thereof beneath the exit end of the nozzle 37 so that a blast of the gas can atomize the molten metal flowing from an opening 48 in the tundish 35 and thence through the nozzle 37 and direct the gas and molten metal droplets toward the opening 31 in the cover 28 of the vessel 12.
- An exhaust port 49 in the side wall of the vessel 12 provides an exist for the inert gas.
- An appropriate alloyed charge of the desired composition is first weighed up and melted in a suitable crucible (not shown). With the recirculating water flowing into the inlet pipe 22 and thence out of the outlet pipes 26. the top surface of the hearth 16 is thereby cooled.
- the atomizing gas enters the inlet pipe 39 of the tundish assembly 14, passes through the chamber 41, and then enters the atomizing chamber 13 to purge it. After purging the chamber 13, the molten metal charge is poured into the tundish 35 so that the molten metal flows from the opening 48 into the nozzle 37. As the molten metal leaves the exit end of the nozzle 37, the atomizing gas strikes the molten metal stream to break up the stream into finely-divided particles.
- this impact quenches the molten particles to solidify them even before they are finally cooled upon splattering against the surface of the hearth 16.
- the gas and atomized metal droplets flow downwardly into contact with the water-cooled hearth 16 to completely quench the metal droplets.
- the operation of the apparatus is stopped so that the metal droplets can be removed from the hearth 16 by removing the cover 28. Thereafter, the operation can be repeated.
- the metal droplets removed from the chamber 13 are then consolidated into solid stock by a hot working process or other consolidation process such, for example, as the process disclosed in co-pending application Ser. No. 435,733, filed on Feb. 26, 1965, by the present inventor.
- a hot working process or other consolidation process such as the process disclosed in co-pending application Ser. No. 435,733, filed on Feb. 26, 1965, by the present inventor.
- the apparatus 50 produces metal powder continuously without the necessity of periodically stopping the operation to remove the accumulated powder from the hearth.
- the apparatus 50 includes as its principal elements a vessel 52 having an atomizing chamber 54 and slanted at an angle with respect to the axis of the vessel 52, a recirculating water vessel 58 having a chamber 59 containing recirculating water for cooling the underside of the hearth 56, an atomizing nozzle and tundish assembly 60 for directing a stream of gas and atomized metal droplets onto the hearth 56, and an exhaust port 62 in the side wall of the vessel 52 at the bottom thereof for withdrawing the quenched metal droplets from the apparatus 50.
- the tundish assembly 60 directs a blast of inert gas under a relatively higher pressure than the gas for the apparatus 10, to produce atomized metal droplets, which are splattered against the cooled metal hearth 56 to rapidily quench the metal droplets. Due to the higher gas pressures, the agitation of the gas stream lifts the quenched droplets in the form of flakes from the hearth 56. The slanting surface of the hearth 56 causes the metal flakes to rebound from the hearth 56 toward the exhaust port 62. Therefore, the hearth 56 is continuously cleared of the realloyed flakes to provide a continuing operation of producing the metal flakes. The flakes are conveyed by the exhaust port 62 to a plurality of filter bags (not shown) for collection purposes.
- the vessel 52 is in the shape of an inverted truncated cone.
- the metal hearth 56 is composed of a conductive material, such, for example, as copper.
- the plane of the hearth 56 is disposed at an acute angle with respect to the vertical axis of the vessel 52 to direct the metal flakes from the surface of the hearth 56 to exhaust port 62.
- the water vessel 58 is mounted on the vessel 52 at the underside of the metal hearth 56 so that the hearth 56 forms the top wall of the chamber 59.
- Water under pressure from a pump enters the chamber 59 via an inlet pipe 64 and leaves the chamber 59 via an outlet pipe 66 connected to the pump for recirculating the water to the inlet pipe 64.
- the recirculating water cools the underside of the metal hearth 56, and consequently the top surface of the hearth 56 is cooled by conduction.
- the tundish assembly 60 is identical to the abovedescribed tundish assembly 14.
- the tundish assembly 60 is mounted on a top Wall 66 of the vessel 52 over an opening 68 therein to enable the stream of gas and atomized metal droplets to be projected into the chamber 54.
- the inert gas may be recirculated after leaving the exhaust port 62 to the tundish assembly 60.
- Cutting tools were prepared from alloy A97 prepared by conventional methods and by the new atomizing unit. When used to turn AISI 4340 steel of R 40 hardness, the conventional material had an average tool life of about 4 min., when cutting at f.p.m. The same alloy prepared in the new atomizing chamber had a tool life of approximately 20 min. under the same conditions.
- Oxide-free powders or flakes are produced because there is no water in the collection chamber.
- Wrought stock made from the powders or flakes has cleaner structures, higher strength, and improved cutting performance in the case of tool alloy powders.
- a method and apparatus for producing prealloyed metal powder by recirculating water in contact with the underside of a metal hearth to cool the top surface of the hearth by conduction, atomizing molten metal with a blast of gas inert to the metal, and then directing the atomized metal into contact with the top surface of the cooled metal hearth to quench the atomized metal.
- Continuous production of the metal powder Without interruption of the operation for removal of the powder from the vessel is accomplished by providing an apparatus having a slanting metal-hearth in accordance with the present invention for splattering the metal droplets against the cooled hearth to rapidly quench the metal droplets, and then for directing the quenched droplets in the form of flakes toward an outlet port.
- a metal-producing apparatus having a vessel and having means mounted on top of said vessel for atomizing molten metal with a blast of gas inert to the metal to direct the atomized metal into an atomizing chamber of said vessel, wherein the improvement comprises:
- a hearth mounted on said vessel and disposed at the bottom of said atomizing chamber
- the distance between said means mounted on top of said vessel and said hearth being sufficiently short so that the atomized metal is not completely quenched at the time it first contacts the surface of the hearth.
- a metal-powder producing apparatus having a vessel and having means mounted on top of the said vessel for atomizing molten metal with a blast of gas inert to the metal to direct the atomized metal into an atomizing chamber of said vessel, wherein the improvement comprises:
- a hearth mounted on said vessel and disposed at the bottom of said atomizing chamber; and means mounted on the vessel beneath said hearth for cooling the underside of said. hearth thereby to cool the top surface of said hearth by conduction,
- the distance between said means mounted on top of said vessel and said hearth being sufliciently short so that the atomized metal is not completely quenched at the time it first contacts the surface of the hearth.
Description
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US64531867A | 1967-06-12 | 1967-06-12 |
Publications (1)
Publication Number | Publication Date |
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US3533136A true US3533136A (en) | 1970-10-13 |
Family
ID=24588539
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US645318A Expired - Lifetime US3533136A (en) | 1967-06-12 | 1967-06-22 | Apparatus for producing metal powder |
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US (1) | US3533136A (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3814558A (en) * | 1969-09-04 | 1974-06-04 | Metal Innovations Inc | Apparatus for producing low oxide metal powders |
US3988084A (en) * | 1974-11-11 | 1976-10-26 | Carpenter Technology Corporation | Atomizing nozzle assembly for making metal powder and method of operating the same |
US4080126A (en) * | 1976-12-09 | 1978-03-21 | The International Nickel Company, Inc. | Water atomizer for low oxygen metal powders |
US4339401A (en) * | 1976-12-09 | 1982-07-13 | The International Nickel Company, Inc. | Process for producing metal powders having low oxygen content |
US4386896A (en) * | 1979-03-23 | 1983-06-07 | Allied Corporation | Apparatus for making metallic glass powder |
EP0131969A2 (en) * | 1983-07-19 | 1985-01-23 | Nippon Kinzoku Co., Ltd. | Process for manufacturing amorphous alloy powders |
US4778516A (en) * | 1986-11-03 | 1988-10-18 | Gte Laboratories Incorporated | Process to increase yield of fines in gas atomized metal powder |
US4780130A (en) * | 1987-07-22 | 1988-10-25 | Gte Laboratories Incorporated | Process to increase yield of fines in gas atomized metal powder using melt overpressure |
US4784302A (en) * | 1986-12-29 | 1988-11-15 | Gte Laboratories Incorporated | Gas atomization melt tube assembly |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1568364A (en) * | 1926-01-05 | Evaporatob | ||
US2583452A (en) * | 1946-11-27 | 1952-01-22 | Standard Oil Dev Co | Manufacture of hollow magnetite bead catalyst |
US2618013A (en) * | 1949-08-02 | 1952-11-18 | Lunkenheimer Co | Apparatus for forming pellets |
US2701775A (en) * | 1950-03-22 | 1955-02-08 | Joseph B Brennan | Method for spraying metal |
US3309733A (en) * | 1964-07-14 | 1967-03-21 | Smith Corp A O | Apparatus for producing metal powder |
-
1967
- 1967-06-22 US US645318A patent/US3533136A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1568364A (en) * | 1926-01-05 | Evaporatob | ||
US2583452A (en) * | 1946-11-27 | 1952-01-22 | Standard Oil Dev Co | Manufacture of hollow magnetite bead catalyst |
US2618013A (en) * | 1949-08-02 | 1952-11-18 | Lunkenheimer Co | Apparatus for forming pellets |
US2701775A (en) * | 1950-03-22 | 1955-02-08 | Joseph B Brennan | Method for spraying metal |
US3309733A (en) * | 1964-07-14 | 1967-03-21 | Smith Corp A O | Apparatus for producing metal powder |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3814558A (en) * | 1969-09-04 | 1974-06-04 | Metal Innovations Inc | Apparatus for producing low oxide metal powders |
US3988084A (en) * | 1974-11-11 | 1976-10-26 | Carpenter Technology Corporation | Atomizing nozzle assembly for making metal powder and method of operating the same |
US4080126A (en) * | 1976-12-09 | 1978-03-21 | The International Nickel Company, Inc. | Water atomizer for low oxygen metal powders |
US4339401A (en) * | 1976-12-09 | 1982-07-13 | The International Nickel Company, Inc. | Process for producing metal powders having low oxygen content |
US4386896A (en) * | 1979-03-23 | 1983-06-07 | Allied Corporation | Apparatus for making metallic glass powder |
EP0131969A2 (en) * | 1983-07-19 | 1985-01-23 | Nippon Kinzoku Co., Ltd. | Process for manufacturing amorphous alloy powders |
EP0131969A3 (en) * | 1983-07-19 | 1985-03-06 | Nippon Kinzoku Co., Ltd. | Process for manufacturing amorphous alloy powders |
US4647305A (en) * | 1983-07-19 | 1987-03-03 | Nippon Kinzoku Co., Ltd. | Process for manufacturing amorphous alloy powders |
US4778516A (en) * | 1986-11-03 | 1988-10-18 | Gte Laboratories Incorporated | Process to increase yield of fines in gas atomized metal powder |
US4784302A (en) * | 1986-12-29 | 1988-11-15 | Gte Laboratories Incorporated | Gas atomization melt tube assembly |
US4780130A (en) * | 1987-07-22 | 1988-10-25 | Gte Laboratories Incorporated | Process to increase yield of fines in gas atomized metal powder using melt overpressure |
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Owner name: COLT INDUSTRIES OPERATING CORP. Free format text: MERGER AND CHANGE OF NAME;ASSIGNOR:CRUCIBLE CENTER COMPANY (INTO) CRUCIBLE INC. (CHANGED TO);REEL/FRAME:004120/0308 Effective date: 19821214 |
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Owner name: CRUCIBLE MATERIALS CORPORATION, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:COLT INDUSTRIES OPERATING CORP.;REEL/FRAME:004194/0621 Effective date: 19831025 Owner name: CRUCIBLE MATERIALS CORPORATION, A DE CORP. Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:COLT INDUSTRIES OPERATING CORP.;REEL/FRAME:004194/0621 Effective date: 19831025 |
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Owner name: MELLON BANK, N.A. FOR THE CHASE MANHATTAN BANK (NA Free format text: SECURITY INTEREST;ASSIGNOR:CRUCIBLE MATERIALS CORPORATION, A CORP. OF DE.;REEL/FRAME:004490/0452 Effective date: 19851219 Owner name: CHASE MANHATTAN BANK, THE (NATIONAL ASSOCIATION) A Free format text: SECURITY INTEREST;ASSIGNOR:CRUCIBLE MATERIALS CORPORATION, A CORP. OF DE.;REEL/FRAME:004490/0452 Effective date: 19851219 Owner name: MELLON FINANCIAL SERVICES CORPORATION Free format text: SECURITY INTEREST;ASSIGNOR:CRUCIBLE MATERIALS CORPORATION, A CORP. OF DE.;REEL/FRAME:004490/0410 Effective date: 19851219 Owner name: MELLON BANK, N.A. AS AGENT FOR MELLON BANK N.A. & Free format text: SECURITY INTEREST;ASSIGNOR:CRUCIBLE MATERIALS CORPORATION, A CORP. OF DE.;REEL/FRAME:004490/0410 Effective date: 19851219 |