JPS61217504A - Production of porous aluminum - Google Patents

Abstract

PURPOSE:To obtain a porous metal in which blank materials are securely bonded to each other by cutting the blank material formed by cladding a low- melting Al alloy to the surface layer of an Al core material to a chip shape, etc. and heating the same in a molding tool. CONSTITUTION:The low-melting alloy 2 of Al-Pb, Al-Sn or Al-Pb-Sn is thinly clad on the surface layer of the core material 1 consisting of Al, Al alloy. The clad blank material is cut to a tip, fiber or wire shape. The cut blank materials are packed into the molding tool where the materials are heated to the liquidus line temp. of the low-melting alloy + or -10 deg.C and is molded under the pressure. The molding is then forcibly air cooled. The porous aluminum welded with the cut clank material metal 1 by the low-melting alloy 2 can be molded to a desired shape by the above-mentioned method. The porous aluminum has high mechanical properties and above all, ductility and permits easy bending, machining, etc.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing porous aluminum.

[Conventional technology]

Various methods have been proposed to produce porous metals, including a sintering method that utilizes the diffusion phenomenon of metal atoms caused by external thermal energy at the interface between two contacting powder metals. As a manufacturing method that utilizes the porosity of other materials, there is an incineration method in which metal is attached to the surface of expanded polystyrene using a surface treatment method such as electrodeposition, and then the expanded polystyrene is burned to obtain a mesh-like porous metal. By baking water-soluble particles such as sodium chloride into a predetermined shape,
There is an elution method in which a molten metal is injected under pressure into the gaps between the particles and solidified, and then the sodium chloride is dissolved in water to obtain a network-like porous metal.
A foaming method is known in which a porous metal is obtained by adding a gas generating compound such as a hydride of r to supersaturating the gas content of the molten metal and solidifying the metal to create a porous metal.

[Problem that the invention seeks to solve]

However, in the above-mentioned sintering method, it takes several hours for the metal atoms to diffuse, and if there is dirt or foreign matter on the contact surface, the diffusion rate is extremely reduced and the bonding force between the metals is weakened. (There is a problem that the mechanical properties deteriorate as a result, and in the incineration method or elution method that uses the porosity of other materials, styrofoam oxides and chloride may be present inside the produced porous metal.) There is a risk that sodium particles, etc. may remain, and there are problems such as low mechanical strength due to the thinness of the metal body.Furthermore, in the foaming method, there are variations in the location of pores, and the molten metal There is a large temperature difference in the temperature distribution, especially near the bottom of the furnace and near the surface of the molten metal, and the solidification rate also depends on the size of the pores, resulting in uneven pore distribution and unstable quality.

In addition to the above, lightweight particle diffusion methods are also known.
The porous metal produced by this method has an extremely low porosity and cannot be called a true porous metal.

[Means for solving problems]

The present invention was devised in view of these points of view, and has good productivity and workability, allows for arbitrary control of pore size and porosity, and has strong intermetallic bonds and no residual foreign matter. The present invention provides a method for producing porous aluminum.

That is, the present invention uses aluminum or an aluminum alloy as a core material, and the surface layer of the core material has Fil<Al-Pb system,
After cladding with Al-Sn-based or Aj-Pb-Sn-based alloy and cutting this clad material into chips, fibers, wires, etc., it is placed in a mold for molding, etc., and heated in a heating furnace, etc. This is a method for producing porous aluminum, in which the cut material is heated to the liquidus temperature of the alloy ±10°C and then fused with the alloy and formed into a desired shape. and the surface layer of the core material is l<Al-Pb system, Al-Sn system.

Alternatively, clad with an Aj-Pb-Sn alloy, cut this clad material into chips, fibers, wires, etc., apply flux, 9 put it in a mold, etc., and heat it in a heating furnace, etc. This is a method for producing porous aluminum, in which the cut material is heated to the liquidus temperature of the alloy ±10° C., and the cut material is fused with the alloy and formed into a desired shape.

[Effect]

In the method of the present invention, as shown in FIG.
) When a chip-shaped, ll1i-shaped, wire-shaped metal material A whose surface layer is thinly clad with gold 1 (2), which has a lower melting point than the core material (1), is placed in a mold, a plurality of chips are formed. Alternatively, if the fibers are in mechanical contact so that they are intertwined with each other and the low melting point metal (2) is heated and melted in this state, the intertwined contact points become horizontal due to capillarity, so the second
As shown in the figure, the molten metal aggregates in this horizontal gap, and the molten low-melting point metal (2) fuses the chip-shaped or fibrous metal to each other, creating a metallic bond. It will be done.

〔Example〕

Hereinafter, the method for producing porous aluminum of the present invention will be specifically explained based on Examples.

In Figure 1, A3003 aluminum alloy is used as the core material (
As 1), one or both sides of the core material (1) is coated with Aj having a melting point lower than that of the core material (1) by preferably 150 to 250°C.
A metal (2) composed of Sn, such as AJ1 aluminum alloy, is crimped and metallically bonded by hot plastic processing such as hot rolling, or a low-melting point metal (2) is made by radiation method. A type of clad plate welded to the surface of the core material (1) at a cladding ratio [thickness of core material (1)/thickness of metal (2)] 1 to 1000, total plate thickness 0.05 to
Create within a 2M range.

Here, the composition of the above A3003 aluminum alloy is Mn
: 1.3% by weight, Cu: 0.10% by weight, Fe: 0.2
% by weight, Zn: 0.1% by weight, and the composition of the AJ1 aluminum alloy is Sn: 12°0% by weight, Cu: 0.
It was 7% by weight.

In addition, as the core material (1), pure aluminum, AI
-M (j-based alloy, Al-Mn-based alloy, AI-Va-S
r-based alloy, Aj-CLJ-based alloy, AI-Zn-MQ-based alloy, etc., and the metal (2) may be an Al-Sn-based alloy containing 4 to 50% by weight of Sn. Furthermore, each component of Pb and 5n-Pb was
Aj-Pb system containing ~50% by weight or Aj-Pb-
It may be an Sn-based alloy, or a plurality of the above alloys may be used in combination.

Next, use a cutting machine such as a shearing machine to cut the clad material into a strip of width 1.0 mm x length 350 JIII, or 1.51111 x 1.5 nm.
After cutting into m+ square chips, these materials are degreased and washed with ethyl alcohol to obtain metal materials A in the form of fibers or chips.

This fibrous or chip-like metal material A is filled into a mold, but in this example, the fibrous metal material A
When filling, a pressure device such as a hydraulic press was used, and pressure molding was carried out at a molding pressure of 50 Kg/cd to 10,000 at 9/ci. Further, in the case of chip-shaped metal material A, the filling was performed by natural filling.

After filling the metal material A into the mold, the mold is placed in a heating furnace with an inert gas atmosphere and heated to the liquidus temperature of the low melting point metal (2) ±10°C, and the mold is heated to the above temperature. After reaching , the mold is removed from the furnace and, after forced air cooling (using a fan in this example), the porous aluminum is removed from the mold.

In this example, the core material (1) was fused by melting the low melting point metal (2) by heating, but during the fusion by this low melting point metal (2), the core material (1) was melted. The low melting point metal (2) does not necessarily need to be in a completely molten state, but may be in a semi-molten state as long as an adhesive effect can be obtained.

In addition, before putting the metal material A into the mold, 7 lux of potassium aluminum fluoride salt was mixed into ethyl alcohol at a rate of about 1 g/100 cc to make a slurry, and the wire mesh basket was placed in the slurry. By immersing the material, taking it out from the slurry, and then drying it, preliminary cleaning of the metal material A becomes unnecessary. In addition to the potassium aluminum fluoride salt, the above-mentioned flux may be any other conventionally known 7-lux, preferably a non-corrosive flux.

In addition, although the above-mentioned heating furnace uses an inert gas atmosphere heating furnace, it may be any one of a normal heating furnace, a vacuum heating furnace, and a combination of an inert gas atmosphere heating furnace and a vacuum heating furnace. Further, the metal material A is cut into chips, 1
Although it is formed into a wire rod, it may be formed by cutting a wire rod, and its length, width, thickness, etc. are arbitrary.

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.

〔Effect of the invention〕

According to the method for producing porous aluminum of the present invention: (a) Compared to conventional sintering methods, heating and holding times are shortened, productivity is significantly improved, and costs can be reduced.

(b) Conventional sintered metals and foamed metals are brittle and have poor workability, whereas the products obtained by the present invention have extremely high mechanical properties, especially ductility (elongation), and are difficult to bend, cut, etc. It's easy.

(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 with the method of the present invention, the pore size and porosity can be changed arbitrarily by simply changing the shape of the material. , its control range is wide.

(d) Since the metal bond is strong, it is resistant to heat shock and can be welded, for example.

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

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

(g) It has electrical conductivity and has a high current collecting effect.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams showing the state in which metal materials are bonded to each other in the method of the present invention. A...Metal material (1)...Heartwood, (2)...Low melting point metal, Patent applicant Nippon Light Metal Co., Ltd. Agent Patent attorney Satoshi Nakamura
Hiro (2 others) A; GokA Taka1↑λ 1st [:);;1
1: lζ2', 112: other #I! , 烹子图2

Claims (5)

[Claims] (1) Aluminum or aluminum alloy is used as the core material,
The surface layer of the core material contains Al-Pb system, Al-Sn system, or Al
- Clad a Pb-Sn alloy, cut this clad material into chips, fibers, wires, etc., and then heat it to the liquidus temperature of the alloy ±10°C to produce the cut material. A method for producing porous aluminum, characterized in that the above-mentioned alloys are fused together and formed. (2) In each of the above alloys, Pb, Sn or Pb-
Claim 1, wherein the Sn component is 4 to 50% by weight
The method for producing porous aluminum as described in Section 1. (3) Aluminum or aluminum alloy is used as the core material,
The surface layer of the core material contains Al-Pb system, Al-Sn system, or Al
- Clad a Pb-Sn alloy, cut this clad material into chips, fibers, wires, etc., apply flux, and heat this to the liquidus temperature of the alloy ± 10 ° C. A method for producing porous aluminum, characterized in that the cut materials are fused together and formed using the alloy. (4) In each of the above alloys, Pb, Sn or Pb-
Claim 3, wherein the Sn component is 4 to 50% by weight
The method for producing porous aluminum as described in Section 1. (5) The method for producing porous aluminum according to claim 3, wherein the flux is a KF-AlF_3-based flux.