JPS6227503A - Production of thin sheet-like sintered metallic member - Google Patents

Abstract

PURPOSE:To easily produce a thin sheet-like sintered metallic member having an increased density by kneading metallic raw material powder consisting of a desired compsn. and having fine grain sizes with an org. binder, extruding a thin sheet material and removing the org. binder by heating, then sintering the molding. CONSTITUTION:The raw material powder consisting of the alloy powder substantially coinciding with the compsn. of the desired final product or the plural powder mixtures composed of the constituting elements of the above-mentioned final product and having <=50mu grain size is mixed and kneaded with the org. binder to prepare the plastic kneaded matter. The kneaded matter is extruded into the thin sheet shape material having the shape resembling to the shape of the final product. The above-mentioned extruded molding is then heated in a vacuum or non-oxidizing atmosphere of a reducing or inert gas, by which the org. binder is removed. The extruded molding after the removal of the binder is subjected to compaction molding in succession thereof, by which the thin sheet-like sintered metallic member having approximately the true density is obtd. The thin sheet-like sintered metallic member is obtd. from the extruded molding having <=200mm width and <=10mm thickness without the generation of foaming, shape collapsion, etc. by the above-mentioned method.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a thin plate metal sintered member.

[Conventional technology]

Thin plate products are ubiquitous in the field of materials such as metal materials in general, plastics, rubber, and ceramics. In the field of metal materials, which is the subject of the present invention, thin plate materials are manufactured using methods such as forging, hot rolling, and cold rolling. On the other hand, with regard to plastics, rubber, and ceramics, attempts have been made to use an extrusion molding method to obtain seven plates by mixing the above materials with a binder and extruding them in a plastic state after mixing through a die.

[Problem that the invention seeks to solve]

As mentioned in the previous section, the concept of manufacturing thin sheets using extrusion molding using powder as a raw material is commonly used in ceramics and plastics, but the reality is that it is rarely seen in metal materials. It is.

This is because the manufacturing technology for raw material powder compatible with extrusion molding methods, the selection of organic binders to be used, and the method for increasing density after molding have not been developed.

The organic binder used is required to have a small amount, high viscosity, high strength of the molded product, and uniform dispersion. Furthermore, after molding, it is necessary that it be easily removable and that no harmful decomposition products remain. Several binders have been disclosed that are useful for injection molding of thermoplastic and thermosetting plastics.

For example, in JP-A-55-113511, polyethylene,
A method of using polystyrene, acrylonitrile-butadiene-styrene copolymer and a silane coupling agent or a titanium coupling agent in combination, JP-A-55-113500 discloses a ceramic powder characterized by using a silane cross-linked polyalkene resin. , or an injection or extrusion molding method for metal powder materials, and JP-A-56-159248 discloses a polytetramethylene phthalate binder. All of these are mainly made of plastic, but it is extremely difficult to remove the binder, and it is usually difficult to remove the binder from products with a thickness of 10 nm.
If the temperature rate is not below 5-b, foaming and deformation will occur frequently.

[Means for solving problems]

The present invention solves the above problems by mixing and kneading metal or alloy powder with an organic binder, forming a thin plate material by extrusion, removing the organic binder, and compacting by sintering. A metal sintered member is obtained. That is, the present invention has a water-soluble organic binder as a main component, and methyl cellulose (hereinafter referred to as CMC) at a weight ratio of 1.0.
-7.0% Contains 5.0-15.0% water, 1.0-10.0% glycerin as a plasticizer, wax emulsion, stearic acid emulsion, microcrystalline as a dispersant or lubricant. It is characterized by containing one or more of them in a total amount of 1.0 to 10.0% at 5z or less. Most of the moisture is removed during drying after extrusion molding, and the binder is subsequently removed in a non-oxidizing atmosphere such as vacuum, reducing, or inert gas at a temperature in the range of 300-700°C. At this time, vacuum, Ar, N2. He
In such an atmosphere, C is a decomposition product of the binder.
3-09 parts remain. When the binder is removed in H2, residual C from the binder can be almost eliminated. Therefore, debinding in H2 is necessary for materials that avoid the presence of C in products. Although it is possible to predict the residual C value and reduce the C in the raw material powder in advance, in order to accurately control the C value, debinding in H2 is preferable.

The particle size of the raw material powder used should be 50μ or less to ensure uniform dispersion of the powder at the time of crosstalk, to ensure the strength of the compact,
Necessary for improving sintered density.

The average particle size is preferably in the range of 5 to 20 μm; if the particle size is too fine, it becomes difficult to remove the binder. Further, it is desirable to use a powder form with as high a packing density as possible. It is necessary that the apparent density be at least 30% or more.

〔Example〕

The invention will be explained below by way of examples.

Example 1 Al5I C1 equivalent to T15, 51%, Si 0.
41%.

Mn0.2%, Cr4.03%, W 11.05%, M
A water atomized pre-alloy powder was prepared consisting of 0.8% O, 5.1% Co, 5.2% Co, the balance iron and inevitable impurities. The average particle size is 45μ and the 02 content is 1800p.
It was pm+.

0.3% of graphite powder was added to a portion of the powder, which was then dry mixed and ground in an attritor to give an average particle size of 5 μm and 15 μm.

Add 3% CMC (commercial product name: 5M400) to this powder.

After adding 8% water, 2.0% microcrystalline wax, 1% stearic acid emulsion, and 0.7z glycerin, the mixture was kneaded for 15 minutes using a kneader kneader. This mixed wire body was molded into a thin plate material with a width of 200 m and a thickness of 5+ m using an extrusion molding machine. The green density at the time of molding was 51%, and it was dried at 50° C. for 2 hours under weak vacuum. This dry body was heated to H2,0°1T
orr vacuum, Ar atmosphere at 100°C/) Ir at 500°C
After raising the temperature to ℃, the binder was removed by holding for 2 hours.

These three binder-removed products were vacuum sintered under a vacuum of 10'' Torr at a temperature in the range of 1180 to 1240°C.

Vacuum and Ar debinding materials have a sintering temperature of 1180°C.
The true density is reached at ℃, and at this time C is 2.2%02 is 40P
It was pm. On the other hand, the H2 theory binder material is 1240
The true density was reached by sintering at °C, and the C content at this time was 1.51% 0□ was 60 ppn+. The C content of the debinding material was 2.60% for the vacuum debinding material, 2.54% for the Ar debinding material, and 1.81% for the H2 debinding material. The sintered body of the H2 binder-removed material removes C from the binder.
It was found that there was virtually no residual carbon, and the vacuum Ar debinding material had about 0.8% carbon residual.

The shrinkage rate after sintering was 211 parts in the width direction and 22.1% in the thickness direction, and a thin plate material with good flatness was obtained. As for the shrinkage rate, all reached the true density, so no significant difference was observed from the binder-removed atmosphere.

Note that 1100 mash of water atomized powder, which has the same composition as in Example 1 and is normally used for sintering, was kneaded with the same binder. The crosstalk body showed almost no viscosity, and although the amount of water added was increased to 15%, no tendency for improvement was observed. Next, a mixed wire body was prepared by increasing the amount of CMC to 6% and the amount of microcrystalline wax to 4.0%. Although it exhibited a viscosity that enabled extrusion, the molded product partially collapsed after the binder was removed, making handling virtually impossible.

Example 2 The powder of the same attritor as in Example 1 was also mixed with C.
0.3% of CMC (commercial product name 60SH-400
0) 5%, glycerin 6.5%, bearing part and pressure kneader
The mixture was kneaded for 15 minutes.

The subsequent steps were the same as in Example 1, and after removing the binder with H2, LHr sintering was performed at 1240°C. The density of the sintered body is 8
．． 21, which is almost the true density, and the C content is 1.52%.
0□ was 72 pp+*.

Example 3 GO, 89%, Si 0.32%, Mn 0
．． 28%, Cr 3.97%.

A water atomized pre-alloyed powder was obtained containing 5.98% W, 5.12% Mo, and 1.92% V, the balance being iron and unavoidable impurities. The amount of 02 in this powder was 1700 ppm.

After adding 0.3% C to this powder, it was crushed with an attritor to obtain a fine powder with an average particle size of 12 μm. CMC to this powder
(commercial product name 60SH-4000) 2%, glycerin 1
After adding 8% of water, the mixture was kneaded for 30 minutes using a Henschel mixer. From this crosstalk body, the width is 1100a, the thickness is 10ffI1
1 extrusion molding was performed. 50'CX in a little less than 1 vacuum after molding
After drying for 2 hours, the temperature was raised to 700°C at a heating rate of 150°C/Hr in H2 gas, maintained at IHr, and then cooled in a furnace. This is 1
The density of the sintered body obtained by performing vacuum sintering at 235° C. for 15 hours was approximately 100% true density, and a thin plate material having a width of 80.3 mm and a thickness of 8.08 mm was obtained. Wood thickness 5III
Cold rolling was performed up to II. A good thin plate material could be obtained without any defects occurring during processing.

Similarly, standard heat treatment of 1200° C. quenching and 560° C. (1+1) hours was performed. The hardness was HRC65.4 and the bending strength was 370 kg/1II112. This value was almost the same as that of the material made by the melting method.

Example 4 3% pure SL powder (0
, 7μ), 2.1% CMC and 2.1% glycerin.
5 pairs, add 7.5% water, and use a kneader mixer to mix 3
Kneaded for 0 minutes. This mixed wire body was extrusion molded into the mold of Example 1, dried under a weak vacuum, heated to 500° C. at a heating rate of 200° C./Hr in an H2 atmosphere, maintained at IHr, and then cooled in a furnace.

This material was sintered in vacuum at 1450°C x IHr. Density is 96.1%, CO, 3%, 023400p
It was pm. Then, magnetic annealing was performed in H2 at 1000°C x IHr. C decreased to 0.02%. Magnetic properties: He 0.40e, Br 11100 Gauss
, μmax 13430 characteristics were obtained.

In this example, high-speed tool steel and Fe-3S i soft magnetic material were described, but the present invention is not limited thereto, and can be applied to stainless steel, general structural steel, and others. Needless to say.

〔Effect of the invention〕

As described above, according to the present invention, a thin plate of high alloy steel can be easily manufactured by powder metallurgy. Of course, the present invention is not limited to thin plates, but by making the die shape of the extrusion molding machine have a different cross-sectional shape, thin plates with irregular cross-sections can also be manufactured, which is extremely useful industrially.

Claims (1)

[Scope of Claims] 1. An alloy powder having a particle size of 50 μm or less and having a composition substantially matching the composition of the desired final product, or a mixed powder of a plurality of constituent elements of the desired final product is used as a raw material powder with an organic binder. After mixing and kneading, it is made into a plastic kneaded body, after which a thin plate material having a similar shape to the final product is extruded, and then the extruded body is placed in a non-oxidizing atmosphere such as a vacuum, a reducing atmosphere, or an inert gas. 1. A method for producing a thin plate metal sintered member, comprising: removing the organic binder by heating, and then consolidating the extruded body after the binder has been removed by a sintering method. 2. A method for producing a thin plate metal sintered member, in which the extruded body has a width of 200 mm or less and a thickness of 10 mm or less. 3 The organic binder is water-soluble, the total amount thereof is 1.0 to 10.0% by weight, and the solvent water is 5.0 to 15.0%.
% of the manufacturing method of a thin plate metal sintered member according to claim 1 or 2. 4 A type of methylcellulose with an organic binder of 1.0 to 7.0% by weight, 1.0 to 10.0% of glycerin as a plasticizer, 5% or less of wax emulsion as a dispersant or lubricant, and stearin. Acid emulsion 5%
Hereinafter, the total amount of microcrystalline is 5% or less, the total amount of these is 1.0 to 10.0% by weight, and the water of the solvent is 5.0 to 5%.
15.0% of the manufacturing method of a thin plate metal sintered member according to claim 1 or 2. 5. The thin plate according to any one of claims 1 to 4, which has a density after sintering of 97% or more and is subjected to plastic working such as forging and rolling after sintering to obtain high density and a desired final shape. A method for producing shaped metal sintered parts.