Classifications

• • 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
  • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
  • B22F1/14—Treatment of metallic powder
  • B22F1/145—Chemical treatment, e.g. passivation or decarburisation

Definitions

• the present invention relates to a method for producing an aluminum powder press-formed product.
• a thin metal container 26 having a desired shape for example, a shape of a chassis of an automobile part or the like
• the metal container 26 is vacuum-sealed with aluminum powder 11 mixed with titanium powder, magnesium powder and the like.
• an inert gas such as an argon gas is injected into the metal container 26 at a temperature of 100 or more by the heater 25 at a temperature of 100 or more to apply a pressure of 100 MPa or more.
• a part of the aluminum powder 11 is pressed into the same shape as the metal container 26 to obtain an aluminum alloy product.
• 22 is an upper lid
• 23 is a lower lid.
• the present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for manufacturing an aluminum powder press-molded product capable of obtaining an aluminum alloy product having excellent strength and toughness.
• a method for manufacturing an aluminum powder press-molded article of the present invention comprises: contacting an aluminum powder with a fluorine-based gas in a heated state to form a fluoride film on the surface of the aluminum powder; Immediately before molding, the fluoride film formed on the surface of the aluminum powder is removed, and then the aluminum powder is pressed to form a pressed product.
• the aluminum powder is brought into contact with a fluorine-based gas in a heated state before the aluminum powder is pressed.
• the fluorine-based gas is removed by the fluorine-based gas and the surface of the aluminum powder is cleaned, and at the same time, the fluoride film is formed on the surface of the aluminum powder. Is formed.
• This fluoride film is stable and prevents the formation of an oxide film on the dough of aluminum powder and adsorption of 0, until the subsequent removal process.
• the fluoride on the surface of the aluminum powder is decomposed and removed to expose the aluminum powder dough. By doing so, no oxide film is formed on the surface of the aluminum powder during the pressure molding, and the pressure-molded product has excellent strength and toughness.
• the fluorine-based gas used in the production method of the present invention is at least one fluorine selected from NF S , BF 3 , CF 4 , HF, SF e , and F i. It refers to those obtained by incorporating a source component in inert gas such as N 2. Among these fluorine source components, reactive, surface in NF S such as handling properties is practical also excellent S.
• the production method of the present invention comprises, as described above, aluminum powder (aluminum alone or a mixture of other metal powders such as titanium powder and magnesium powder) with the fluorine-based gas, for example, NF
• the fluorine-based gas for example, NF
• the surface of the aluminum powder is fluorinated by contacting at a temperature of 250 to 400.
• H 2 gas or the like is sprayed to remove fluoride from the surface of the aluminum powder to expose the green body of the aluminum powder. Get the goods.
• the concentration of the fluorine source component such as NFi in such a fluorine-based gas is, for example, from 1,000 to 10,000 ppm, preferably from 20,000 to 70,000 ppm, and more preferably from 30,000 to 50,000 ppm.
• the contact time with such a fluorine-based gas may be appropriately selected depending on the type of aluminum powder, the type of powder mixed with the aluminum powder, the heating temperature, and the like, and is usually several minutes to several tens of minutes. Minutes.
• aluminum powder is introduced into, for example, a gas treatment chamber 9 provided in the heat treatment furnace 1 shown in FIG. 1 and brought into contact with a fluorine-based gas.
• the furnace 1 is a bit furnace in which an inner vessel 4 is placed inside a heater 3 provided in an outer shell 2, and an exhaust pipe 6 is introduced into the inner vessel 4 from outside the furnace 1, and a gas introduction pipe 5
• the powder outlet pipe 8 is inserted into the room from the upper side of the gas processing chamber 9 through the inner container 4 through the inner container 4.
• Gas is supplied to the gas introduction pipe 5 from the cylinders 15 and 16 via the flowmeter 17 and the valve 18.
• 13 is a vacuum bomb and 14 is an abatement device.
• the gas treatment chamber 9 heated to a predetermined reaction temperature, the mixing of the gas inlet pipe 5 of the fluoropolymer gas from the gas outlet 5 a drilled at the tip, for example, NF 3 and 1 2 gas Blow up the gas.
• an on-off valve (not shown) provided in the powder storage tank 7 is opened to supply the aluminum powder 11 in the powder storage tank 7 to the powder outlet pipe 8, and gas treatment is performed from the powder outlet 8a at the lower end thereof.
• the above NF generates fluorine as an active group at a temperature of 250 to 400, and removes organic and inorganic contaminants on the surface of the aluminum powder 11 at the time of collision with the aluminum powder 11 while simultaneously producing this fluorine. Reacts with oxides such as t 0 ,, Ai (OH), etc. on the surface of the aluminum powder 11 as shown in the following formula to form a very thin fluoride film ⁇ F, on the surface of the aluminum powder 11.
• the oxide film on the surface of the aluminum powder 11 is converted into a fluoride film, and Os adsorbed on the surface is also removed. And, in the absence of O 2 , 2 , and H 20 , such a fluorinated film is stable at a temperature of 600 or less at the following temperature, and the aluminum powder 11 1 before the subsequent removal step is removed. prevent oxidation skin ⁇ formation and 0 2 of adsorption to the fabric.
• a fluoride film is formed on the surface of the furnace material in the first stage, and the film causes damage to the subsequent furnace material surface due to fluorine-based gas. Will be prevented.
• These fluorinated aluminum powders 11 are stored in a powder storage box 10 arranged at the bottom of the gas processing chamber 9.
• the aluminum powder 11 is immediately mixed with the various powders, vacuum-enclosed in the above-mentioned gold-plated container without heating, and pressure-formed using a known HIP device 20 to obtain a desired shape.
• Aluminum alloy products
• the oxide film on the surface of the aluminum powder 11 is removed before being applied to the HIP device S20, it is necessary to heat the aluminum powder 11 mixed with various powders. Therefore, even if a powder having a low consolidation temperature is used as the powder to be mixed with the aluminum powder 11, the obtained press-formed product is excellent in mechanical properties such as strength and toughness.
• the aluminum powder is brought into contact with the fluorine-based gas in a heated state before the aluminum powder is pressed.
• a passive film such as an oxide film on the surface of the aluminum powder is changed to a fluoride film, and the surface of the aluminum powder is protected. Therefore, even if there is a lapse of time between the formation of the fluoride film and its removal, the fluoride film formed on the surface of the aluminum powder protects the surface of the aluminum powder in a good state, The formation of the oxide film again on the surface of the aluminum powder is prevented.
• This fluoride film is disintegrated and removed just before pressure molding, thereby exposing the surface of the aluminum powder. Therefore, there is no need to heat aluminum powder mixed with various powders before pressing, and it is melted as powder mixed with aluminum powder. Even when a powder with a low ⁇ temperature is used, the resulting press-formed product has excellent mechanical properties such as strength and toughness.
• FIG. 1 is a cross-sectional view of a heat treatment furnace used in one embodiment of the present invention
• FIG. 2 is a conceptual diagram of the ⁇ , ⁇ .
• the aluminum powder After cleaning the aluminum powder with trichloride ethane, it is brought into contact in a heat treatment furnace 1 as shown in FIG. 1 in a gas atmosphere containing 500 ppm of NF 3 at 300 ° C. for 3 minutes. Then, after uniformly spraying H 2 gas immediately before the pressing, the titanium powder, engaged magnesium powder and mixed under vacuum sealed in a metal container and the Aruminiumu alloy product having a desired shape by a known HIP apparatus . This aluminum alloy product had much higher strength and toughness than the conventional aluminum alloy product.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Powder Metallurgy (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)

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Citations (3)

• 1990
  • 1990-11-20 JP JP2316564A patent/JP2868890B2/ja not_active Expired - Fee Related
• 1991
  • 1991-11-20 WO PCT/JP1991/001600 patent/WO1992008561A1/ja unknown
  • 1991-12-06 TW TW080109564A patent/TW197389B/zh active

Patent Citations (3)

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