JPS61159540A - Manufacture of fiber reinforced metallic material - Google Patents

Abstract

PURPOSE:To manufacture the titled material in which metal is distributed perfectly and uniformly between short fibers, by powder compacting a mixture of metal powder and reinforcing fibers, putting it in vessel closedly, and press forming it by hot hydrostatic pressure. CONSTITUTION:Metal powder (Al, Cu, etc.) having about 0.0001-0.01mm particle diameter, and short fibers, whiskers (SiC fiber, etc.) having about 0.0001-0.2mm length are mixed so that short fibers are regulated to about 5-50% vol. ratio. The mixture is pressed to compacted body by press and said body is put closedly in a prescribed vessel. The vessel is set in hot hydrostatic press, and pressing force of about 1.0-1.5 times as much as deformation resistance value, is applied thereto at temp. lower than m.p. of metal by about 50 deg.C. Next, temp. is rised higher slightly than m.p. of metal, and pressure of about 80-150MPa is applied. By this way, the titled material superior in mechanical characteristic and workability, etc. is obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for manufacturing fiber reinforced metal materials (FRM),
By compacting a mixture of metal powder and reinforcing short fibers, sealing this in a container and performing hot isostatic pressing,
It is pressed so that a fiber-reinforced metal material with good bonding between metal and fibers and excellent workability, mechanical strength, etc. can be obtained.

[Prior art and its problems]

As a conventional manufacturing method for fiber reinforced metal materials (hereinafter abbreviated as FRM), there is a method in which reinforcing fibers are first introduced into molten metal, dispersed, and cooled. However, due to reasons such as the difference in specific gravity between the fiber and metal and the high viscosity of the molten metal, the dispersion of am is not uniform, and the resulting FRM
There were drawbacks such as large variations in mechanical properties.

Another method is to wrap continuous fibers around a metal body, pour molten metal around the metal body, and apply pressure in a semi-molten state. However, this method can only be used for continuous fibers and has the disadvantage that the product shape is limited.

Alternatively, there is a method in which fibers are aligned and wound around a metal drum, molten metal is sprayed by plasma spraying to create a base material, and the base materials are stacked and pressurized. However, this method also does not allow the metal to completely penetrate between the fibers, and in order to make thick products, multi-level Vc must be stacked, which limits the shape of the product. Furthermore, there is a method of pouring molten metal into the reinforcing fibers by attaching the molded body to the reinforcing fibers, but this method also has the problem that the metal does not completely penetrate between the fibers, and it cannot be used with high-temperature molten metal. Although permeability is improved, there is a risk of reaction with fibers.

As described above, the conventional FRM manufacturing method has various problems, and it has been difficult to obtain an FRM with good percent properties.

[Means for solving problems]

Therefore, in this invention I/c, the above problems are solved by performing hot isostatic pressing after compaction 1-1 of the mixture of metal powder and reinforcing fiber, and excellent properties are obtained. FRM can now be manufactured.

The present invention will be explained in detail below.

In this invention, the reinforcing fiber has a length θ000/~02
Short fibers or whiskers are used in between. The types of fibers are not particularly limited, and include boron fibers, SiC-loved boron fibers (3o1-aic), SiC fibers, carbon fibers, alumina fibers, beryllium fibers, tungsten fibers, At208 whiskers, SiC whiskers, etc. It is selected after taking into consideration the compatibility with the matrix metal, reactivity, etc.

Further, the metal powder used has a particle size of θ000/~aO/m, and although the type is not limited, particularly preferred is A/.

These include Cu, 'l'i and their alloys.

Then, these short fibers and metal powder are mixed and compacted to form a compact. The mixing ratio of short fibers and metal powder is s ~ for short fibers in terms of volume ratio! rOqb. Short fibers! If it is less than f-, no reinforcing effect can be obtained. ro
If it exceeds m, the short fibers become excessive and uniform dispersion becomes impossible, which is disadvantageous.

A ball mill, a tumbler, or the like is used as a mixing means for these, and it is also preferable to use a dispersion medium such as an organic solvent in order to increase the mixing efficiency.

The resulting mixture is then compacted. A normal powder press machine is used for powder compaction, and the compact is pressed with a pressure of several to several tens of tons. The shape of the molded body is usually cylindrical in relation to subsequent steps.

Then, this compacted powder body is sealed in a container.

This container has flexibility and is easily deformed during the next step of hot isostatic pressing, applying pressure to the compacted compact housed inside, and exceeding the melting point of the powder metal. Powder metal KA is used.
When using t'PCu, mild steel is used. Also,
This container internal pressure can be determined not only by the compacted compact but also by the compacted compact and a metal material, for example, a cylindrical compacted compact placed in a metal pipe and housed in a cylindrical container.
It is also possible to produce a composite material of M and golden fly.

This container is then placed in a hot isostatic press to perform hot isostatic pressing. The pressure and heating conditions are as follows: As the temperature is raised, the pressure is also increased.<7. First, the temperature is raised to the melting point of the metal. As the temperature rises, the pressurizing force increases. The pressing force at this time is relatively low, and is set to an extent that does not cause volumetric expansion due to temperature rise of the compacted compact.
The deformation resistance value at a temperature 3θ℃ lower than the melting point of the metal is 70~
The pressing force is 13 times, preferably 77 to 13 times.

If the pressing force is less than 10 times, the degree of density improvement will be insufficient due to insufficient pressure, and if it exceeds 15 times, it will be excessive and there is a risk that the molded product will collapse. This first-stage low-pressure application prevents the molded article from deforming.

Next, when the temperature reaches the melting point and the powdered metal melts, high pressure is applied to the second stage. It is sufficient that the temperature at this time be at or slightly above the melting point.

Further, the pressing force is approximately gO~/jOMPa.

If it is less than tOMPa, the penetration of the molten metal into the short fibers will be insufficient, and/or if it exceeds tOMPa, the penetration effect will not increase any further, which is uneconomical. The time for pressurizing this fourth step is
Although it varies depending on the size of the molded body, the combination of short fibers and metal, etc., it is usually about 1 minute to 3 hours. This first stage of pressure allows the molten metal to penetrate well into the short fibers, promoting physical or chemical bonding between the two.

Then, the container is cooled and the pressing force is lowered to complete the hot isostatic pressing. Next, the container is opened and the molded article (FRM) is taken out. This molded body can be processed by rolling, forging, extrusion, drawing, etc. as necessary.
The FRM is subjected to S processing and cutting to obtain a desired shape of the FRM.

[Effect]

In this method of manufacturing FRM, fine metal powder and short fibers having similar dimensions are mixed, so that the mixing and dispersion of both can be uniformly performed. In addition, since the powder compact is sealed in a container and hot isostatic pressing is performed, the pressurizing medium is prevented from entering the powder compact, and heating and pressing can be carried out under sealed conditions. Therefore, there is no deterioration due to oxidation of the material. Furthermore, since hot isostatic pressing is carried out in two stages, the metal slowly and completely penetrates into the short fibers, improving the bond between the two, and also eliminating the minute gaps. The strength is improved, resulting in an FRM with high mechanical properties. Additionally, since the process is carried out under pressure at a temperature slightly above the melting point of the metal, it is possible to suppress the reaction between the metal and the delicate material. Furthermore, since short fibers are used, secondary processing of the obtained FRM is facilitated, and complex shapes can be processed. Furthermore, this method also eliminates warpage due to high strength F with a high content of reinforcing fibers.
RM can also take a back route.

[Example 1] SiC whiskers (average diameter 0.gμm 1 length 110μm
> Go volume part and pure At powder (particle size 200 mesh bath,
atomized powder) and stirred with acetone in a V-type mixer for Ii' hours.

Then, the mixture is heated in a constant temperature bath to ≠O'CVc to completely remove acetone. Next, this mixture is compacted using a powder press machine, and the diameter! rpm, and a disc-shaped molded body with a thickness of 30 mm. By stacking 7θ sheets of this disc-shaped molded body, the inner diameter is 5/w1 and the outer diameter is 7! r m1ll, 300m long pure A/, put it in a pipe, and then put it in a soft steel pipe (container) VC with inner diameter g0, wall thickness 5mm, length 330mm, and the top and bottom The lid was covered with a mild steel plate made of the same material and sealed by electron beam welding.

Next, this container was set in a hot isostatic press machine and hot isostatically formed. The conditions are shown in FIG.

Under these conditions, the pressure is gradually reduced until the temperature rises to 690°C. The temperature should be about 0MPa and the temperature should be A90'GK.
After sufficiently melting, a pressure of 100 MphVC is applied.

After hot isostatic pressing, the molded body is taken out from the container, heated to ttso℃, hot extruded into a wire rod with a diameter of 20 m, and further wire drawn and annealed to a wire rod with a diameter of 2111 II.
It was made into a wire rod.

The mechanical properties of this thin material were investigated. The results are shown in Table 1.

[Example 2] Using pure copper powder (particle size l!rθ mesh bath, atomized powder) as the metal powder, a copper powder with a diameter of 2
11II+ wire rod was created. The conditions for hot isostatic pressing are as shown in Figure 2! D. Hot extrusion conditions for FRM are g20°C. Similarly, the mechanical properties of this equipment were measured and the results are shown in Table 1.

[Example 3] Using Ti powder as the metal powder, the same operation as in Example 1 was performed to obtain a wire rod with two diameters. The hot isostatic pressing conditions are as shown in Figure 3], and the hot extrusion conditions for FRM are g50.
℃. Table 1 shows the mechanical properties of the wire.

[Comparative Example 1] Only the same SiC whiskers as in Example 1 were pressed into a shape with a SO diameter and a thickness of 30 m using a pressing force of 3 tons).

This molded body was placed in a bottomed cylindrical metal mold with a diameter of 100 m and a depth of 720 m, and the entire mold was placed in a cylindrical metal mold with a diameter of 100 m and a depth of 720 m. After heating with O'CVC, it is cast into a pure At molten metal mold at 30°C. Pressurize the molten metal with a punch while it is melting to promote penetration of the molten metal. After solidification, the outer periphery of the cylindrical FRM is turned to have a diameter of gOm and a length of 1
00w5llC Finish. Next, this is the inner diameter gOwm
, placed in a mild steel pipe with an outer diameter of gS and a length of 100 mm, welded and sealed both ends with the same material, heated to SO ℃, hot extruded with a diameter of 20w5VC, and processed into a wire drawing process. The wire rod is annealed and has a diameter of 2 IIm. The mechanical properties of this wire are also shown in Table 1.

[Comparative Example 2] A wire rod of diameter C was obtained by pressing in the same manner as in Comparative Example 1, except that a Cu molten metal having a temperature of /lOθ°C was used.

The mechanical properties of this product are also shown in Table 1.

[Comparative Example 3] In Example 3, hot isostatic pressing was carried out under the same conditions as shown in Figure q, and the same VC211I+ wire rod was obtained. The mechanical properties of this product are also shown in Table 1.

As is clear from Table 2 and Table 1, the mechanical properties of the FRM obtained by this invention are greatly improved compared to those of the conventional method, and the reinforcing effect of the fibers is sufficiently produced. is recognized.

〔Effect of the invention〕

As explained above, 1. According to the FRM farming method of the present invention, the metal is completely and uniformly distributed among the short fibers, and there are no voids or voids inside the assembled fibers, and there is no possibility that the fibers and the metal may be mixed together. FRM with excellent mechanical properties, workability, etc. without any reaction.
is obtained.

[Brief explanation of drawings]

The drawings are graphs showing molding conditions during hot isostatic pressing in Examples and Comparative Examples of the present invention. Figure 1 □ Time Figure 3 Figure 4 ■ Indication of the case Patent Application No. 606 of 1985 2 Title of the invention Process for manufacturing fiber reinforced metal material 3 Person making the amendment

Claims (3)

[Claims] (1) A method for manufacturing a fiber-reinforced metal material in which a mixture of metal powder and reinforcing fibers is compacted, the compacted product is sealed in a container, and then pressure-molded using hot isostatic pressure. (2) The method for producing a fiber-reinforced metal material according to claim 1, in which the hot isostatic pressing is performed in two stages. (3) In the above two-stage pressurization, the first stage pressurization is performed at a temperature lower than the melting point of the powder metal and at a low pressure, and the second stage pressurization is performed at a temperature higher than the above melting point and a higher pressure than the first stage pressure. A method for producing a fiber-reinforced metal material according to claim 2.