JPS637343A - Production of porous metallic body - Google Patents

Abstract

PURPOSE:To easily produce a porous metallic body having high porosity and high strength by mixing a single metal or alloy and metallic salt powder having the m. p. higher than the m. p. of said metal or alloy and a prescribed grain size at a prescribed mixing ratio, and molding the mixture, then removing the metallic salt from the molding. CONSTITUTION:The single metal such as Al, or Fe or the alloy thereof and the metallic salt powder such as CoCl2, or SnCl2 having the m. p. higher than the m. p. of these materials and prescribed grain size corresponding to the desired porosity are mixed and molded. The molding can be executed by mixing the above-mentioned single metal or alloy in the form of the powder having the prescribed grain size with the metallic salt powder, molding the mixture and sintering the molding or mixing the same in the molten state with the metallic salt powder, molding the mixture and solidifying the molding. The resultant molding is thereafter treated with a solvent which is stable to the above-mentioned single metal or alloy, does not attack the same and can dissolve the above-mentioned metallic salt, by which the metallic salt is dissolved away. The porous metallic body having the high porosity corresponding to the mixing ratio of the metallic salt is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a porous body of a single metal or an alloy.

[Conventional technology]

Conventionally, porous metal bodies have been produced by a powder metallurgy method in which powder of a single metal or an alloy is pressed and sintered, and the pore diameter thereof has been from several microns to 100 microns. However, in order to maintain the strength of the porous metal body made in this way,
It was necessary to reduce the porosity to 60% or less.

Therefore, as a method for producing a porous body with high porosity,
A method in which a metal is deposited on an open cell foam made of synthetic resin by electrodeposition, and then the synthetic resin is removed by heating and decomposition (
Japanese Patent Publication No. 47-10524), and a method in which the surface of particles of thermally decomposable organic matter is coated with a metal film, the particles are filled into the luteal pores of foamed metal, and the organic matter is decomposed and removed by heating (Japanese Patent Publication No. 57-1989).・123942> etc. are being proposed.

[Problem that the invention seeks to solve]

However, in manufacturing the above-mentioned high porosity metal porous body,
In the former case, the pore size is limited to 300 μm due to the manufacturing limit of the base resin diameter, and in addition, uneven electrodeposition occurs on the resin surface, making it difficult to obtain a uniform structure. In both cases, it is difficult to manufacture a metal porous body with a high porosity, and even if it were manufactured, it was impossible to obtain satisfactory physical properties.

As a result of research on how to create a metal porous body with high porosity and high strength, the present inventors found that after mixing a metal salt with a metal and molding it, if the metal salt is removed 1, the area It was discovered that pores are formed.

The present invention was made based on the above discovery, and an object of the present invention is to provide a method for producing a porous metal body with high porosity and high strength.

(Means for Solving the Problems) The present invention has been made to achieve the above object, and its gist is to provide an elemental gold alloy or an alloy, and this elemental gold F! Alternatively, after mixing with metal salt powder of a predetermined particle size and having a melting point higher than that of the alloy and molding, 1. A method for producing a porous metal body in which metal salts are removed.

[Specific structure and operation of the invention]

Next, the method of the present invention will be explained in detail.

The metal used in the present invention is a general elemental metal or an alloy thereof (hereinafter referred to as metal), such as AJXSn, Pb
, Bi, Mn, Si, Ng, Zn, Cd, Li, C
LJ, Fe, etc. t3 J: U Any of these alloys can be used.

In addition, the metal salts used for pore formation are stable against heat,
It is necessary that the melting point is higher than that of the metal to be mixed, that it is stable to the metal, and that it is soluble in the solvent. For example, cobalt chloride (COCl2), W chloride (SnC+2), cadmium chloride (CdC12), calcium chloride (CaC1z)
, ferrous chloride (FeC12), copper chloride (CLJ)
CI ), cupric chloride (CuCl2), beryllium chloride (8CCIz), magnesium chloride (MQClz)
, manganese chloride (MnC12), lithium chloride (1-t
cIz), cerium chloride (CeClt), etc., and are selected depending on the type of metal to be made porous.

Also, F? to remove the metal salts mentioned above? There are no particular restrictions on the medium as long as it dissolves the metal salt and does not corrode or strongly react with the metal that becomes porous, but due to its physical properties such as boiling point and toxicity, water, ethyl alcohol, acetone, etc. ,
Examples include ethyl acetate, and water and ethanol are particularly preferred because they are easy to handle.

The combination and type of the metal salt and solvent for pore-forming are selected depending on the type of metal used as the raw material for the intended metal porous body.

Next, we will explain the manufacturing method of the porous metal body.The method of the present invention uses ordinary casting and powder metallurgy techniques as they are, mixes metal salt as a component of the composition, forms a molded body, and then It is sufficient to remove the metal salt.

Therefore, processing such as sintering, extrusion, rolling, rapid cooling, etc.
You can use the method as is.

For example, a metal powder with a predetermined particle size and a metal salt powder are mixed in a predetermined ratio, heated and press-molded to create a metal sintered body, and this molded body is washed with a solvent to elute and remove the metal salt. or by melting the metal and adding and mixing metal salt powder to the metal and forming it into a thin layer so that the metal salt is deposited on the surface of the solidified metal. There is a method of washing this with a solvent to remove metal salts.

Metal salts can be removed using the above solvents by washing with a solvent, immersing the molded body in a solvent and vibrating it with ultrasonic waves, spraying a pressurized solvent, or washing with a heated solvent. etc., but the method is not limited to the above method.

The porous metal body produced by the above method (the porosity can be freely adjusted by selecting the particle size of the metal salt and the mixing ratio with the metal, and since the metal salt is present during molding) It is possible to mold the molded product by applying sufficient pressure under heat without worrying about the disappearance of pores, and the strength of the molded product is extremely high, and the porous material has the desired porosity.
body is easily obtained.

〔Example〕

Next, the present invention will be explained in detail by showing Examples and Comparative Examples.

Example 1 Aluminum alloy powder (JIS #3004) and magnesium chloride powder were mixed in a weight/h1 ratio of 5=1, 40 m9 of 9IMφ gold was filled into the tank, and the mixture was heated to 500°C for 10 min while pressurizing at 1 t/ci. It was held for a minute to sinter.

After cooling, the molded pellets were placed in 100 d of ethanol and vibrated by ultrasonic waves to elute magnesium chloride. This was dried and various measurements were performed.

As a result, the thickness was 50μ and the bulk density was 1.27 g/C.
m', porosity is 51%, tensile strength is 15 K9/
It was ms'.

Example 2 Aluminum powder: Magnesium powder: Zinc powder: Manganese chloride powder was mixed in a weight ratio of 64:8:8:20, and this was put into a mold of 1c20#l with an inner diameter of 9mφ! 1 was filled and held at 480° C. for 30 minutes under a pressure of 1.5t10+1 to form pellets.

This pellet was processed and washed for 3 hours using a Soxhlet extractor containing ethanol to form a porous material. This was dried and various measurements were performed. The resulting size is 9 mm.
φ, weight 16η, thickness 550μm, bulk density 0.469/
CD, the porosity is 83%, and the tensile strength is 25Kg/
It was "u".

Example 3 Aluminum: Magnesium: Manganese as a weight ratio:
Magnesium chloride powder of 3Qwt% relative to the molten alloy was added and mixed into the molten alloy containing silica in a ratio of 94:4:1:0.4, and the molten metal in a mixed phase state was mixed with 10% of the molten alloy.
．． It was poured between 21Nl rollers rotating at OOOrpm to create an alloy foil. This alloy foil was immersed in a water tank and vibrated with ultrasonic waves to elute magnesium chloride. The obtained alloy foil has a thickness of 150 μm and a bulk density of 0.4'
It was a porous body with a porosity of 85% and a tensile strength of 15 kg/-.

Comparative Example 1 A sintered body was produced by pressing and heating under the same conditions as in Example 1, except that no magnesium chloride powder was added and the mold was filled with 60η. This pellet has a thickness of 4C1m and a bulk density of 2.3
The porosity was 9.6% at 5 g/ci.

〔effect〕

As described above, the method of the present invention mixes metal and metal salt powder, molds the mixture, and removes the metal salt with a solvent. Porous metal bodies with high porosity can be easily produced.
This is an advantageous method that offers many advantages, such as the ability to freely adjust the pore diameter and porosity.

Claims (4)

[Claims] (1) Production of a metal porous body characterized by mixing a single metal or an alloy and a metal salt powder of a predetermined particle size and having a higher melting point than the single metal or alloy, molding the mixture, and then removing the metal salt. Law. (2) The method for producing a porous metal body according to claim 1, wherein the single metal or alloy is a powder with a predetermined particle size. (3) The method for producing a porous metal body according to claim 1, wherein the single metal or alloy is a metal in a molten state. (4) The metal salt is stable with respect to single metals or alloys,
The method for producing a porous metal body according to any one of claims 1, 2, and 3, which is soluble in a solvent that does not attack the single metal or alloy.