JPH05156385A - Manufacturing method of porous metal fiber sintered body - Google Patents

Abstract

PURPOSE:To provide the method for manufacturing a metallic fiber porous sintered body in which the manufacturing process is remarkably simplified to increase the manufacturing efficiency as well as the accuracy, quality and reliability of the product are improved and its cost is remarkably reduced. CONSTITUTION:This method is characterized by packing 1 metallic fibers (a) {or (a1} into a die, subjecting the metallic fibers (a) {or (a1} packed in the die to sintering 2a and 2b and thereafter melting away 3 the die to manufacture a metallic fiber porous sintered body (b).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a metal fiber porous material manufactured by filling metal fibers such as stainless steel into molds of various shapes, molding and sintering, and then melting and removing the molds. The present invention relates to a method for producing a sintered body.

[0002]

2. Description of the Related Art A conventional example of a metal fiber porous sintered body will be described with reference to a stainless steel fiber porous sintered body. The stainless steel fiber porous sintered body has excellent tensile strength, High porosity (65% or more) as compared with porous sintered compacts with high packing density (porosity 25-55%), which have wear resistance, electrical conductivity, and thermal conductivity and are manufactured by powder metallurgy. Manufactured and widely applicable to various filters, oil-impregnated bearing materials, soundproofing materials, oil and gas stoves, wicks for lamps and burners, heat generating and luminous bodies, etc., and opened stainless steel fiber to a specified size. After it is made into a non-woven fabric and sintered, the porous sintered body is post-processed (punching press processing, cutting processing, etc.) to form a sheet-shaped porous sintered body, and the sheet-shaped porous sintered body is multi-staged. Layered on top of each other and then integrally connected by welding, soldering, etc. The shape of cylindrical shape and is manufactured by molding into a cylindrical shape such as a stainless steel textile porous sintered body (products).

[0003]

The conventional porous metal fiber sintered body requires a complicated post-processing such as press working, cutting, and laminated connection (welding, soldering) after sintering as described above. However, the manufacturing process becomes complicated, the manufacturing efficiency is poor, the material loss is large, the yield is reduced, and the cost is high.
There is a problem in product accuracy, quality, and reliability such that the sintered state is easily damaged due to post-processing and variations easily occur.

The present invention was developed in order to address the above-mentioned problems, and the object of the present invention is to greatly simplify the manufacturing process and increase the manufacturing efficiency.
An object of the present invention is to provide a manufacturing method of a metal fiber porous sintered body, which is improved in accuracy, quality and reliability of a product, and which is greatly reduced in cost.

[0005]

According to the present invention, a metal fiber is filled in a die formed thinly, and the metal fiber filled in the die is sintered, and then the die is By manufacturing the porous sintered body of metal fibers by melting and removing it, post-processing is almost unnecessary and the manufacturing process is greatly simplified and manufacturing efficiency is improved, and product accuracy, quality and reliability are improved. is doing.

[0006]

[Function] The metal fiber is filled in a thin mold and molded into a desired shape corresponding to the metal fiber porous sintered body (final product), and the filling rate provides a desired high porosity. Adjust easily and freely, sinter the metal fibers filled in the mold, sinter the metal fibers evenly and accurately, and then melt and remove the mold after sintering. Manufactured into a porous sintered body of metal fibers, the outer shape, sintering performance, voids, etc. of the sintered metal fiber porous body are not particularly impaired, and post-processing such as shape modification is almost unnecessary. The manufacturing process is greatly simplified, the manufacturing efficiency and the yield are significantly improved, and excellent product accuracy, quality and reliability are obtained.

[0007]

EXAMPLE FIG. 1 shows the manufacturing process of one embodiment of the present invention, and FIG. 2 shows various molds used in manufacturing the metal fiber porous sintered body of the present invention. In the figure, a is metal fiber as a raw material, a1 is a nonwoven fabric of metal fiber, 1 is a mold filling step, 1
a, 1b, 1c are various molds, 2a is a vacuum sintering process, 2
b is a non-oxidizing atmosphere sintering step, 3 is a mold melting step, b is a product, that is, a metal fiber porous sintered body,
Is a raw material for producing the metal fiber porous sintered body b, and includes, for example, SUS316, SUS316L having excellent corrosion resistance,
Stainless steel materials such as SUS304, SUS304L,
Hot extrusion-rolling followed by cold wire drawing to diameter 2-100
A stainless metal fiber or the like formed into μ long fibers or formed into short fibers by cutting or the like is opened by an appropriate means and used. Alternatively, the stainless metal fiber is used as the non-woven fabric a1.

In the mold filling step 1, the opened metal fiber a (stainless steel metal fiber or its nonwoven fabric a1) is
The mold 1a, 1b, or 1c shown in FIG. 2 is filled and pressurized. For example, in order to obtain a desired high porosity metal fiber porous sintered body (product), a filling load (25 to 300 kgf / m)
The filling rate of the metal fiber a (or the nonwoven fabric a1 thereof) in the mold is adjusted by adjusting ² ) and the like, and the shape of the metal fiber a (or its nonwoven fabric a1) is cylindrical, cylindrical, or The metal fiber a (or its nonwoven fabric a1) formed in the U-shaped porous metal fiber porous body b (product) and filled in the mold is sintered together with the mold in a vacuum or non-oxidizing atmosphere. . As shown in FIG. 2, the metal mold is variously formed according to the metal fiber porous sintered body b, that is, its product shape. For example, in the case of stainless metal fiber, it is thinly formed of low carbon steel, Only the mold can be easily dissolved and removed with nitric acid solution.

In the vacuum sintering step 2a, for example, the inside of the sintering furnace is made into a vacuum atmosphere (vacuum degree of 10 ^-3 to 10 ^-5 Torr), and the metal fiber a (or its nonwoven fabric a1) filled in the mold is placed outside. In the non-oxidizing atmosphere sintering step 2b, the sintering furnace is replaced with N ₂ gas and the atmospheric pressure is set to 0 to 760 mmHg. Then, the metal fiber a (or its nonwoven fabric a1) filled in the mold is heated at a temperature of 80 with the mold.
After sintering at 0 to 1400 ° C, the mold is melted and removed.

In the mold melting step 3, in the case of the mold formed of low carbon steel to be thin (0.5 to 1.0 mm thick) as described above, for example, the concentration is 15 to 60% and the liquid temperature is 20 to 80. The metal fiber a filled in the outer mold in a nitric acid solution at ℃
(Or its non-woven fabric a1) for a suitable time (minutes to several hours depending on the material, shape and size of the die) to dissolve the metal fiber a (or its non-woven fabric a1) but not the die, It is removed to obtain a metal fiber porous sintered body b. The metal fiber porous sintered body b is a final product formed into a desired desired shape by neutralization, washing with water, etc., and post-processing such as shape modification is almost unnecessary.

The method for producing the metal fiber porous sintered body of the present invention is as follows:
As described above, the mold filling step 1, the vacuum sintering step 2a, the non-oxidizing atmosphere sintering step 2b, the mold melting step 3 and the like are performed, and the manufacturing process is greatly simplified. Filling only the opened metal fiber a (or its non-woven fabric a1) into the shaped molds 1a, 1b, 1c, etc. (no need to knead the binder), the filling rate, that is, the metal fiber porous material as the final product The porosity of the sintered body b is adjusted to be high (65% or more). Metal fiber a (or its non-woven fabric a1)
Is capable of imparting appropriate repulsion to the fibers by adjusting the mechanical properties, which allows for uniform filling in the mold, and
Very flexible and easy to fill into any desired shape in the mold,
It is molded, and the high porosity is easily and freely adjusted as described above.

Further, in the vacuum sintering step 2a or the non-oxidizing atmosphere sintering step 2b, the metal fiber a filled in the mold is used.
(Or its non-woven fabric a1) is sintered together with the outer die, so that the metal fibers a (or its non-woven fabric a1) are evenly and accurately sintered over the entire area, and are extremely effective in a vacuum or non-oxidizing atmosphere. Sintering performance and reliability have been significantly improved.

Next, in the mold melting step 3, only the outer molds 1a, 1b, 1c are melted and removed to obtain a metal fiber porous sintered body b, and when the mold is removed, the metal fiber porous sintered body is baked. The outer shape, sintering performance, voids, etc. of the bonded body b are not particularly impaired,
Almost no post-processing such as shape modification is required, the manufacturing process is greatly simplified, manufacturing efficiency and yield are significantly improved, cost is reduced, and product accuracy, quality and reliability are significantly improved. ing.

As the metal fibers, various steel materials and various metal fibers other than stainless metal fibers can be applied.
The mold is formed of various materials capable of dissolving and removing only the mold corresponding to the material of the metal fiber,
It is formed into various shapes corresponding to the outer shape of the metal fiber porous sintered body (product).

[0015]

As described above, the present invention comprises the mold filling step, the vacuum sintering or the non-oxidizing atmosphere sintering step, the mold melting step, etc., and the manufacturing process is greatly simplified and the metal fiber is By filling the inside of the mold with a thin wall, it is possible to easily and freely adjust the desired shape and the desired high porosity corresponding to the metal fiber porous sintered body (final product). By sintering the metal fibers filled in, the metal fibers are evenly and accurately sintered over the entire area.Furthermore, by melting and removing the die after sintering, a porous sintered body of metal fibers is manufactured. The outer shape, sintering performance, voids, etc. are not particularly impaired, and post-processing such as shape modification is almost unnecessary,
Along with the drastic simplification of the manufacturing process, the manufacturing efficiency and the yield are remarkably improved, the accuracy, quality and reliability of the product are improved, and the cost is greatly saved. can get.

[Brief description of drawings]

FIG. 1 is a manufacturing process chart showing an embodiment of the present invention.

FIG. 2 is perspective views (A) to (C) of various molds used during the manufacturing process of the present invention.

[Explanation of symbols]

 a metal fiber a1 non-woven fabric (metal fiber) b metal fiber porous sintered body 1 type filling step 1a, 1b, 1c mold 2a vacuum sintering step 2b non-oxidizing atmosphere sintering step 3 type melting step

Claims (1)

[Claims] 1. The metal fiber is filled in a thin mold, the metal fiber filled in the mold is sintered, and then the mold is melted and removed. 1. A method for producing a metal fiber porous sintered body, which comprises producing the above porous sintered body.