JPS6089535A - Manufacture of porous aluminum - Google Patents

Abstract

PURPOSE:To manufacture inexpensively porous Al having superior mechanical properties by sticking powder of an Al-Si alloy to the surface of an Al material cut into wires, putting the material in a metallic mold for molding, and heating it to a proper temp. CONSTITUTION:Powder of an Al-Si alloy is stuck to the surface of an Al or Al alloy material formed by cutting a wire rod into wires or a plate into fibers or chips by coating and drying a slurry of the powder mixed optionally with a flux in an aqueous or volatile soln. The material is put in a metallic mold for molding, and it is heated to the liquidus line temp. of the Al-Si alloy + or -10 deg.C to melt-bond the Al-Si alloy at the contact points of the material. Thus, porous Al having superior mechanicsl properties, especially high ductility and contg. no foreign matter is inexpensively obtd. with high productivity in a short time.

Description

[Detailed description of the invention] The present invention relates to a method for producing porous aluminum.

Conventionally, various means have been provided as methods for producing porous metals. In other words, the method for manufacturing porous metals by sintering is a method that utilizes the phenomenon of diffusion of atoms into gold due to external thermal energy at the interface of two contacting powder metals. It takes several hours to carry out this process, and if there is dirt or foreign matter on the contact surface, the diffusion rate will be extremely reduced, the bonding strength between the metals will be weak, and the mechanical properties will deteriorate.

In addition, as a manufacturing method that utilizes the porosity of other materials, metal is attached to the surface of expanded polystyrene using a surface treatment method such as electrodeposition, and then the expanded polystyrene is completely combusted to obtain a mesh-like porous metal (incineration method). ), or by baking water-soluble particles such as sodium chloride into a predetermined shape, injecting molten metal under pressure into the gaps between the particles, and after solidifying, dissolving the sodium chloride with water to form a network-like porous metal. There is a method to obtain it (elution method), but 1. There is a risk that particles of Styrofoam oxide, chloride, etc. may remain inside the porous metal, and the metal body is thin, so there are drawbacks such as low mechanical strength.

Additionally, lightweight particle diffusion methods have little porosity and are not truly porous metals.

Furthermore, in the manufacturing method (foaming method) in which a gas-generating substance is placed in the molten metal and pores are scattered inside the metal body, a gas-generating compound such as magnesite or hydrides of Ti and ZR is added to the molten metal. In this method, the gas content of the molten metal is supersaturated and solidified to incorporate pores to obtain a porous metal, but there are variations in the boundary surface where pores occur, and the temperature distribution of the molten metal
In particular, there is a large temperature difference between the vicinity of the bottom of the furnace and the vicinity of the surface of the molten metal, and the solidification rate is also affected by the size of the pores, which has the disadvantage that the presence of pores is uneven and the quality is unstable.

The present invention has been made in view of the above-mentioned drawbacks of the conventional art. , l? - Aqueous slurry or volatile solution slurry of Si alloy powder is applied and dried, then placed in a mold and heated in a heating furnace.
Heating the 8i alloy to the liquidus temperature ±10°C, Al
-A method of fusing Si alloy, or applying a mixture of ht;-Si gold alloy powder and flux to the surface of aluminum or aluminum alloy material in the form of lines, fibers, chips, etc., using an aqueous slurry or volatilization. After adhering a slurry of a neutral solution and drying it, the AJ-Si alloy is melted at the contact point of the aluminum or aluminum alloy material using the same process as described above to create a metallic bond. The purpose of the present invention is to provide a method for producing porous aluminum that has strong aluminum and no residual foreign matter.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. The surface of the metal (aluminum alloy) 1 in the form of cylindrical, fibrous, or chip shapes is preferably etched with a caustic soda solution or the like to form fine irregularities, and this surface is coated with a low melting point metal 2 (1-Si).
When an aqueous slurry or a volatile solution slurry of the powder of the alloy is deposited, the result is as shown in FIG. Next, a linear, fibrous, or chip-shaped metal 1 having a low melting point metal 2 attached to its surface is placed in a mold. In this state, as shown in FIG. 2, the metals 1 in the form of wires, chips, and fibers are mechanically intertwined to form a large number of wedge-shaped contact points. Furthermore, as shown in Figure 3 (a) and (b), when the low melting point metal 2 is heated to its melting point, the low melting point metal 2 adhering to the surface melts and penetrates deeply into the surface unevenness. The mutual force of the low-melting point metals 2 binds together. As a result, the linear, chip, and fibrous metals 1 are mechanically and metallically bonded to form a porous metal.

Next, an embodiment of the present invention will be specifically described based on the above-mentioned principle. 6063 alloy continuous casting billet (diameter 10
0φ) to obtain a fibrous material by lathe processing. 60 above
The composition of 63 alloy is Mg0.6%, Si, 0.4%
t'Fe O, 1% (wt%)6. The dimensions of the C1 fibrous material were approximately 1 mm in width and 300 mm in length. Thereafter, the fibrous material is degreased and washed with ethyl alcohol.

On the other hand, A4045 alloy powder having an average particle size of 10 p is mixed into ethyl alcohol to form a slurry. This slurry is applied to the surface of the fibrous material 4o by air spraying. Here, the composition of A4045 alloy is 5ixo
%, FeO, 15%, Zn0.1% (weight%)
It is. Next, after putting the dried fibrous mvJ into a mold, the mold was placed in a heating furnace with a room floor gas atmosphere and heated at the liquidus temperature of the low melting point metal 2 ± 10°C 1. Once the mold has reached the above-mentioned temperature, the mold is removed from the heating furnace, and after forced air cooling (cooling using a fan), the porous aluminum is removed from the mold.

In addition, in the process of slurrying the above-mentioned A4045 alloy powder in ethyl alcohol and adhering this slurry to the surface of the fibrous or chip-shaped metal 1 by an air spray method, aluminum potassium salt Q flux is added. The same purpose can also be achieved by adding 0.0 parts to ethyl alcohol, mixing with A4045 alloy powder, and applying the mixture to fibrous or chip-like metal 1 using an air spray method.

Moreover, the above-mentioned fibrous and chip-shaped metals include pure aluminum, AJ-Mg alloy, Ae-Mn alloy, AI! -Mg
-3i alloy, AI! -Cu-based alloy, Al-Zn-M
Any aluminum or aluminum alloy such as g-based alloy may be used, and the low melting point metal is AI! -3% to 20% Si alloy is preferred. Although a nitrogen gas atmosphere heating furnace was used as the heating furnace, it may be a normal heating furnace or a heating furnace that combines a heating furnace with an inert gas atmosphere and a vacuum heating furnace.

Furthermore, although air spraying was used as the method for applying the slurry, it may be applied by dipping or simply painting.

Furthermore, the shape of the porous aluminum product is formed into a desired shape such as a circle, square, triangle, polygon, etc. using a mold.

As explained in detail above, since the present invention is the above-mentioned manufacturing method, it has the following effects.

(b) Heating and holding times are shorter than conventional sintering methods, improving productivity and reducing costs.

(b) High mechanical properties, especially ductility (elongation). Conventional baked crystals and foamed metals are brittle and have poor workability, whereas the products obtained by the present invention are ductile and can be easily bent, cut, etc.

(c) In the case of the conventional method, the pore size and porosity depend on the manufacturing method and the effective range is narrow, but according to the present invention, the pore size and porosity can be changed arbitrarily by simply changing the shape of the material, and the control range is wide. .

(2) Strong metal bonding is achieved, making it resistant to heat shock, and can also be welded, for example.

(e) There is very little foreign matter contamination or foreign matter remaining.

(f) The heat transfer coefficient is improved due to a significant increase in the heat transfer area.

(g) High electrical conductivity and high current collecting effect.

[Brief explanation of drawings]

1 and 2 are principle diagrams of the present invention, and FIG. 3 (A). (b) is a detailed view of section A in FIG. 1...Fiber-like, chip-like metals, 2...Low melting point metals Patent applicant Nippon Light Metal Co., Ltd. Agent Patent attorney Tosa Hideaki Tosa (Voluntary) January 24, 1931 Manabu Shiga, Commissioner of the Patent Office1, Indication of the case: Patent Application No. 197505 of 19822, Name of the invention: Process for manufacturing porous aluminum3, Person making the amendment Relationship to the case Name of address of patent applicant (474) Nippon Light Metal Co., Ltd. 4, Agent 6, Specification subject to amendment [Contents of amendment] (1) Submit the “Scope of Claims” column of the specification on a separate sheet. (2) The section 1-Detailed Description of the Invention" in the specification is amended as shown in the table below. Claims (1) Aluminum or aluminum alloy in the form of lines, fibers, chips, etc. An aqueous slurry or a volatile solution slurry of A/2l powder of Al-3i is adhered to the surface of the material, dried, placed in a mold, and heated in a heating furnace to form the Al-3i powder. - System A L gold - is heated to 11 phase line temperature ± 10°C, and A I!-8i ・8 is heated at the contact point of the above aluminum or aluminum alloy material.
A method for producing porous aluminum ζnium in which a special effect is produced by fusion-bonding the two. (2) Aqueous slurry or volatile solution slurry was prepared by mixing A4-8i□ series Tamamushi powder and flux on the surface of aluminum or aluminum alloy material in the form of wires, fibers, chips, etc. After adhering the material and drying it, place it in a mold and heat it in a heating furnace to the liquidus line altitude of the artificial 25-earth material ±10°C to form a contact point of the aluminum or aluminum alloy material. At A
l A method for manufacturing porous aluminum in which the special effect is once the Y L button is fused. (3) Above A I-3i Z'''-Blood Si is 3 to 20
A method for producing porous aluminum according to claim (1) or (2). (4) The method for producing porous aluminum according to claim (2), wherein the flux is a KF-AjF-based flux.

Claims (4)

[Claims] (1) AI! -8i alloy powder made into an aqueous slurry or a slurry of a volatile solution is adhered and dried, then placed in a mold and heated in a heating furnace to the liquidus temperature of the AJ-8 metallurgy mentioned above ±10t. A method for producing porous aluminum, characterized in that Al-8i alloy is fused at the contact point of the aluminum or aluminum alloy material. (2) Aqueous slurry or volatile solution slurry of Al-8i alloy powder and slack mixed on the surface of aluminum or aluminum alloy material in the form of wires, fibers, chips, etc. is attached. After drying (r), the above Al-
8i Heating to the liquidus temperature of the alloy ±10°C, and then heating the aluminum or aluminum alloy material at the contact point
I! A method for producing porous aluminum, characterized in that -si alloy is fused. (3) The method for producing porous aluminum according to claim 1 or 2, wherein the kl-8t alloy contains 3 to 20 percent Si. (4) The method for producing porous aluminum according to claim (2), wherein the flux is a KF-AJF type flux.