JPS61166932A - Production of fiber preform - Google Patents

Abstract

PURPOSE:To obtain a preform in which reinforcing fibers including long fibers are uniformly dispersed and which has the strength and rigidity necessary in the stage of pressure casting by calcining the reinforcing fibers impregnated with a soln. prepd. by dispersing powder into an org. binder under specific conditions after drying. CONSTITUTION:The carbon long fibers 12 are taken up into a loop shape by using, for example, a manual winder 10 and are cut in the part A. The cut fibers are bundled in the part B to obtain the fiber bundle. On the other hand, an acrylic resin soln. and acetone which is a solvent are mixed. The binder soln. formed by adding a hardener to such mixture is prepd. An alloy powder is added to the soln. The above- mentioned fiber bundle 14 is immersed into such soln. 18 and the soln. 18 is stirred; at the same time, the bundle 14 is oscillated to penetrate thoroughly the soln. 18 among the fibers of the bundle 14. Then the A powder advances into the spaces among the fibers. The bundle 14 is then drawn out of the soln. 18 and is passed through a glass tube 20, by which the excess soln. is removed and the preform 22 is obtd. After the preform is dried and cured, the preform is calcined in an electric furnace 24 at and for the temp. at and for which the greater part of an org. compd. or org. metallic compd. is decomposed.

Description

[Detailed Description of the Invention] L1 Kaminowa Kokugetsu] 1 The present invention uses small diameter fibers such as long fibers, short fibers, and whiskers made of metal or inorganic material to perform a pressure casting method, a vacuum casting method, etc. The present invention relates to a method for manufacturing a fiber preform for obtaining fiber reinforced metal (FRH).

11. Fiber-reinforced metal (hereinafter referred to as FRH), which is made by reinforcing a light alloy matrix with fibers, has been attracting attention recently because it has excellent properties such as light weight, high strength, high rigidity, and high heat resistance. This is the material that is used. As a manufacturing method for FRH pickling, a fiber preform obtained by molding fibers into a desired shape using an organic or inorganic binder is placed in a mold,
A pressure casting method is known in which molten metal is poured and pressurized with a plunger.

However, in the case of long fibers, even if a binder is used, it is difficult to give the fibers a desired shape and maintain it, and it is also not easy to bundle tens to millions of fibers. Therefore, great care must be taken when placing the formed fibers into the #rI mold, and when molten metal is injected into the mold and pressurized, some of the fibers may be swept away. The fibers may be deformed or even aggregated, resulting in non-uniform dispersion, making it impossible to secure the predetermined volume content (V,) of the fibers for the purpose of mixing. This may cause problems such as: As a result, healthy FRH
It was difficult to obtain the desired strength, resulting in variations in strength, and the reliability of the FRH was impaired.

However, the inorganic binder is effective for short fibers and whiskers that have a lot of tangles between fibers, but it is difficult to apply to long fibers because the binding force is insufficient.
In addition, although the organic binder has sufficient binding strength, the fibers tend to aggregate, and although it can be used to obtain a fiber preform with V, ≧60%, V, = 30%.
It is not possible to obtain a fiber preform with a low fiber volume content, and if organic components remain in the composite bond of matrix metal and fibers, they will adversely affect the properties of the FRH.

On the other hand, there is a method of obtaining FRH by a sintering method such as introducing metal powder between bundled fibers, heating and press forming (for example, JP-A-56
119746) has been proposed, and by applying this method, fiber bundles containing powder can be produced by pressure casting. Although it is envisaged that it could be used as a navy blue preform, it is not possible to apply it because the bonding strength of the powder cannot be expected and the necessary rigidity cannot be obtained.

Another object of the present invention is to disperse reinforcing fibers uniformly without agglomeration,
The object of the present invention is to obtain a fiber preform for fiber-reinforced metal having the strength and rigidity necessary for pressure casting.

The purpose is to prepare a solution of an organic compound or an organometallic compound,
Alternatively, fine powder made of metal or inorganic material is added and dispersed in the solution diluted with an organic solvent, reinforcing fibers are immersed in the solution, and then the reinforcing fibers are taken out from the solution.
This is achieved by forming reinforcing fibers using a solution as a binder, followed by drying, curing, and heating to decompose most of the organic components in the organic compound or organometallic compound that is the binder.

As mentioned above, reinforcing fibers tend to agglomerate when an organic binder is used, but the present inventors have found that by introducing powder between the reinforcing fibers, the spacing between the fibers can be maintained. Focusing on this, we attempted to prevent fiber aggregation and non-uniform dispersion by dispersing the powder in an organic binder. Furthermore, if the organic component of the organic compound or organometallic compound completely disappears during firing of the fiber preform, it will not be possible to maintain the shape of the 1MN preform.
The heating and firing temperature and time are selected such that the amount of decomposition and reduction of the organic component in the organic compound or organometallic compound is 90 to 99% (that is, the remaining amount is 1 to 10%), and thereby pressure casting. When performing this, it becomes possible to ensure the strength and rigidity required for the tj/AM preform. The powder is interposed between the fibers of the I1M preform obtained by firing to maintain the fiber spacing, and the residual organic components are reinforced by the powder incorporated therein, so that the desired properties can be achieved. Fiber volume content V
, and at the same time, sufficient strength and rigidity can be obtained.

When selecting the organic compound or organometallic compound used in the present invention, it is necessary to fully consider the high-temperature deterioration of the fibers when thermally decomposing them. For example, as reinforcement III, high-strength carbon When using acrylic resins, it is necessary to use organic compounds or organometallic compounds that decompose under heat at 400°C or less, as the fibers will deteriorate if heated above 400°C in the air.Acrylic resins, Styrene resins, cellulose resins, etc. are suitable.

Furthermore, when using organometallic compounds, in addition to the above conditions, the metal components remaining after thermal decomposition must have no adverse effect on the fibers, and silicone resins, which are typical of them, must be In this case, the compatibility between the residual SL and the matrix metal must also be considered.

On the other hand, the material of the powder to be added to a solution prepared by diluting an organic compound or an organometallic compound with an organic solvent such as acetone or toluene is determined by the compatibility with the reinforcement 411u and the matrix metal, and is made of the same material as the matrix metal or its material. Metal powder (or alloy powder) containing the main elements
) can be used, and if dissolution into the matrix metal is undesirable, ceramic powders can be used. In the latter case, there is an advantage that a dispersion strengthening effect by ceramic particles can be contemplated.

Further, the particle size of the powder is determined by the reinforcing fiber diameter and the set volume content V of the taI11 preform. For example, when carbon fibers with a diameter of 7 μm are used, a particle size of 10 μm or less is desirable. However, if the set volume content V is low and is 30% or more, powder with a particle size of 40 μm or less can be used even if the carbon fiber has a diameter of 7 μm.

The amount of powder added to the solution is determined in relation to the set volume content ratio (2) of the fiber preform, and as vf becomes smaller, the amount added must be increased accordingly.

Further, as reinforcing fibers, long fibers, short fibers, and whiskers made of metal (e.g., stainless steel) or inorganic materials (e.g., carbon, silicon carbide, alumina) with a diameter of 30 μm or more can be used, and in particular, It is preferable to use the fiber bundle in the form of a bundle of long fibers.

F! by following the steps below. & Miscellaneous preforms are formed into round bars (12N) of high-strength carbon fiber reinforced magnesium alloy composite material.
Rφx 120#) was obtained.

■ Using the hand-cranked winding device 4110 shown in Fig. 1(a), wind the long carbon fiber (east binding 300) 12 with a diameter of 7 μm into a loop, cut it at section A, and cut it at section A. They were bundled together to form a bundle of 900,000 fibers.

The number of fibers is determined in relation to the inner diameter of the glass tube 20, which will be described later, and is aimed at a fiber content volume ratio V=30%.

■Acrylic resin solution (manufactured by Toyo Ink ■ Trademark 8 Biolivine (BPS4668)) and solvent acetone in a ratio of 1:1.
and add 4x of the acrylic resin solution to this.
A binder solution containing a curing agent (polyisocyanate) corresponding to
7/J! full mini-cum alloy powder (JIS7075.
(up to 325 mesh) was added.

The binder solution 18 is immersed in the binder solution 18 according to item 0 above, and the binder solution 18 is stirred and the fiber bundle 14 is vibrated to spread the binder solution 18 between the fibers of the tag bundle 14. By this operation, the aluminum alloy powder also quickly enters between the fibers (see Fig. 1(b)).

■ Pull out the fiber bundle 14 from the binder solution 18, and
), the fiber preformed body (1
2mφX20#l1l) was obtained.

(2) After drying and curing the fiber preform 22, it was heated and fired at 400° C. for 1 hour in an electric furnace 24 under a nitrogen gas atmosphere (see FIG. 1(d)). By heating and firing, the organic components were decomposed, and the remaining organic components were 5x the amount before firing.

■The fired fiber preform 22 is placed in a nitrogen atmosphere for 4 hours.
The mold was preheated at 00℃ for the central part, then set in a pressurized casting mold, and immediately a magnesium alloy (equivalent to 8STHAZ31 or JI3831) with a molten metal temperature of 730℃ was injected, and the temperature was 1000/(jf/Cai). Pressure was applied for 60 seconds.

The results of cross-sectional observation of the FRH obtained in this way show that the fibers are uniformly dispersed without agglomeration, that the fiber preform does not deform during pouring and pressurization, and that the added aluminum alloy powder is absorbed into the matrix metal. It was confirmed that it was completely dissolved and did not retain its original shape.

In addition, a tensile test was conducted on the FRH, and the tensile strength was 85K.
The result was that the elastic modulus was 11.500 Kgf/m 2 .

If no aluminum alloy powder was used under the same conditions (same conditions), agglomeration of m fibers would occur in step (2), resulting in the desired 12 m
A cross-sectional shape of n+φ could not be obtained. As a result of molding FRH using the 4111 preform, the matrix metal did not penetrate into the fiber agglomeration area, resulting in casting defects, the tensile strength was 17 kg/ma+2, and the elastic modulus was 5700 k (1,/a
It was m2.

High-strength carbon fiber with a diameter of 7 μm and Ni plating with a thickness of 0.4 μm (manufactured by Celanese, product name: Selion 6)
A fiber preform was formed under the same conditions as in Example 1, except that aluminum alloy (
Pressure casting was performed using JIS AC4C) under the same conditions as in Example 1 to obtain FRH.

Good FRH was obtained as in Example 1, and according to the tensile test, the tensile strength was 82 #f/aw2 and the elastic modulus was 14.0.
OOK9r/rtm".

11 Pitch-based high-strength carbon fiber (P55 manufactured by LJCC) with a diameter of 11 μm was heated to a diameter of 12M1φ in the same manner as in Example 1.
Aiming for 30%, they made a bundle of 360,000 pieces.

■Polymethyl methacrylate resin (manufactured by Toyo Ink n)
100g/J of pure A1 in a binder solution (solid content 34x) diluted with toluene (trade name: BXX4720)
A powder (particle size of 10 uTrL or less) was added, a carbon fiber bundle was immersed in the solution, and the penetration of the binder solution between the fibers was measured in the same manner as in Example 1.

(2) The carbon fiber bundle pulled out from the binder solution was passed through a glass tube with an inner diameter of 12 mm, dried and hardened, and then fired at 300° C. for 30 minutes in the atmosphere. The residual organic matter component was 7χ before firing.

(2) The fired fiber preform was composited with an aluminum alloy (JIS AC5A) under the same conditions as in Example 1.

The thus obtained FRH was as good as in Example 1, with a tensile strength of 70 and 9r/1ea2; elastic modulus of 17.0
It was 00Kgf/#llI2.

Support i ■ A ■ α alumina IIfi (Fiber FP manufactured by DuPont) with a diameter of 20 μm, iomφX 100m +, V, =
In order to obtain a 50% round fiber preform, 125,000 fibers were bundled.

■Add 50o/j pure AJ powder (particle size of 10μTrL or more) to a binder solution made by diluting silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd.) with toluene, and immerse the α-alumina fiber bundle in the solution. Then, in the same manner as in Example 1, the penetration of the binder solution between the fibers was measured.

■The α-alumina fiber bundle drawn from the binder solution is
It was passed through a die of 0 awφ, dried and cured, and then heated and baked at 500° C. for 2 hours in a nitrogen atmosphere. The residual organic component was 35% of that before firing, and as a result of analysis, silicon, carbon, and oxygen were detected.

■Already fired! The IN preform was set in a ceramic mold with good heat retention, preheated at 700°C, placed in a vacuum chamber, and heated at 750°C at a pressure of 10-2 Torr.
AJ of ℃! The alloy (JIS AC4C) was drained, and after pouring, it was immediately pressurized with an inert gas using a pressure cuff Kgr/ci to obtain FRH.

The thus obtained FRH had fibers uniformly dispersed without agglomeration, a tensile strength of 50/(9f/a+"), and an elastic modulus of 21.0OQN9f/am2.

Back Cover ■1 ■ 300,000 silicon carbide long fibers (manufactured by Nippon Carbon ■, trade name: 22 Calon) with a diameter of 14 μm were bundled to obtain a round rod-shaped fiber preform of 12#lIφX 100m.

■In the same binder solution as in Example 1, 150 g/J!
The S! 3N+ powder (particle size of 5 μm or less) was added and a carbon-silicon material was immersed in the solution, and the penetration of the binder solution between the fibers was measured in the same manner as in Example 1.

■The silicon carbide fiber bundle pulled out from the binder solution is
It is handled through a glass tube of m + φ, and then heated in the atmosphere for 1
It was cured by drying at 50° C. for 1 hour, and then heated and fired at 400° C. for 1 hour in a nitrogen gas atmosphere.

■The fired fiber preform is made using the pressurized F7 method.
Magnesium alloy (equivalent to ASTHA131 or JI
S 831 equivalent).

The thus obtained FRH has fibers uniformly dispersed without agglomeration, a tensile strength of 43, 9 f/rtm2, and an elastic modulus of 9. It was QQQK9f/Ki2.

Friend i■ヱ■ (0.3~μmφ) x several hundred μm silicon carbide whiskers (manufactured by Tokai Carbon ■, trade name: TOKAMAX) 1
60g was added to a binder solution containing AJ powder having the same composition as in Example 3 and stirred.
Pour into a mold with a length of 100#, pressurize with a plunger to remove excess resin, 50mrn x 100mt
A fiber preform of n x 50 mm was obtained.

(2) After drying and curing the preform in the atmosphere, it was fired at 300° C. for 1 hour in the atmosphere. Obtained m
The apparent specific gravity of the cloth g/a molded product was 0.65.

■Set the fired fiber preform in a pressure casting mold and cast it into an aluminum alloy (JIS A) at 150°C.
C4D), and immediately after pouring, the pressure was increased to 1100O.
Pressure was applied for 60 seconds at N/cd.

In the thus obtained FRH, silicon carbide whiskers were uniformly dispersed without agglomeration. For comparison, an FRH obtained using a fiber preform of silicon carbide whiskers formed without using a binder exhibited soaking and cracking of the fiber preform. In addition, the FRH of this example has a tensile strength of 45, 9f/#2, and an elastic modulus of 10.7008.
It was fl fits 2.

An annular m-fiber preform was prepared using the same fibers and binder solution as in Example 1 of the supporting cast and using a simple filament winding apparatus as shown in FIGS. 2 and 3. The high-strength carbon fiber bundle 30 wound around the fiber supply bobbin 32 is guided by a plurality of idle rollers 34, passes through a binder solution (mixture of acrylic resin and AJI alloy powder) 18, and then is passed through a die 36. , setting ``Aiming for ``, the excess resin is removed.

Thereafter, the carbon fiber bundle 30 is wound onto a winding mandrel via a guide 38 that moves in synchronization with the winding mandrel 40. The binder solution 18 binds the resin and A1 into the fiber bundle.
In order to promote the penetration of the powder, it is stirred by blowing air, rotating blades, etc. Further, a synchronous feeding device (not shown) is designed to prevent the fibers from changing in amm diameter due to excessive tension being applied to the fibers after being drawn by the die 36 and before being wound around the mandrel 40.

The annular fiber preform thus obtained was heated and fired under the same conditions as in Example 1, and then composited with an Mg alloy (equivalent to ASTHAZ31) by pressure casting in the same manner as in Example 1. The obtained FRH has an inner diameter of 40maφ and an outer diameter of 50+u.
When machining +φ and applying compressive load “
MQ alloy (ASTHA
231 equivalent)). As a result, the amount of deformation under the same load was reduced to 1/3, confirming a significant improvement in rigidity due to fiber reinforcement.

As is clear from the above explanation, fine powder made of metal or inorganic material is added and dispersed in a solution of an organic compound or an organometallic compound, or a solution thereof diluted with an organic solvent,
Reinforcement III is immersed in the solution, then the reinforcing fibers are taken out from the solution, the reinforcing fibers are formed using the solution as a binder, and then dried, hardened, and fired by heating to remove the organic compound or organic A method for producing a fiber preform has been proposed, which is characterized by decomposing most of the organic components in the metal compound.

According to the method of the present invention, the fiber volume content V is 10
It is possible to obtain a fiber preform suitably selected in the range of ~80%, and the IAG preform has fibers uniformly dispersed without agglomeration, and has high strength and rigidity.
There is no need for jigs such as containers or holders to hold the shape, and i! A high quality FRH can be obtained without damaging the shape of the fiber molded body.

[Brief explanation of drawings]

FIG. 1 shows a manufacturing procedure for a fiber preform according to one embodiment of the present invention, FIG. 2 is a side view showing a manufacturing procedure for a fiber preform according to another embodiment, and FIG. - ■ line arrow view. DESCRIPTION OF SYMBOLS 10... Hand-crank winder, 12... Carbon long fiber, 14... Fiber bundle, 16... Container, 18... Binder solution, 20... Glass tube, 22... - Fiber preform, 24... Electric furnace, 30... Carbon fiber bundle, 32.
...Fiber supply bobbin, 34...Guide roller, 36
...Dice, 38...Guide, 40... Winding mandrel. Agent: Patent attorney Nozomi Ehara, 2 people

Claims (1)

[Claims] A method for producing a fiber preform for fiber-reinforced metals, comprising adding and dispersing fine powder made of a metal or inorganic material into a solution of an organic compound or an organometallic compound, or a solution thereof diluted with an organic solvent. Then, the reinforcing fibers are immersed in the solution, the reinforcing fibers are taken out from the solution, the reinforcing fibers are formed using the solution as a binder, and then dried, hardened, and heated to remove the organic compound as the binder. Alternatively, a method for producing a fiber preform, which comprises decomposing most of the organic components in the organometallic compound.