JP3000404B2 - Method of forming hybrid fiber molded product for fiber reinforced composite member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a hybrid fiber molded article for a fiber reinforced composite member, and more particularly to a method for forming a hybrid fiber molded article for a fiber reinforced composite member from two kinds of reinforcing fibers having different specific gravities. The improvement of the method.

This type of hybrid fiber molded article is used for imparting various properties to a fiber-reinforced composite member, for example, strength and abrasion resistance. In this case, the specific gravity of the reinforcing fiber often differs due to the difference in the composition.

[0003]

2. Description of the Related Art Conventionally, as a seed molding method, two kinds of reinforcing fibers having different specific gravities, for example, various whiskers are mixed and dispersed in a liquid to prepare a slurry-like molding material, and then the slurry-like molding material is prepared. Is known in which a liquid is removed and both reinforcing fibers are deposited at the same time.

[0004]

However, according to the conventional method, since the high specific gravity reinforcing fiber sinks faster than the low specific gravity reinforcing fiber, the hybrid type fiber molded body has a portion mainly composed of the high specific gravity reinforcing fiber. However, there is a problem that a hybrid-type fiber molded product formed mainly in two layers with a portion made of the fiber for low specific gravity reinforcement and in which the fiber for high specific gravity reinforcement is uniformly dispersed cannot be obtained.

[0005] In view of the above, the present invention provides the above-mentioned molding method capable of obtaining a hybrid fiber molded product in which irregular fibers are uniformly dispersed by using irregular fibers as the high specific gravity reinforcing fibers. Aim.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method of forming a hybrid fiber molded article for a fiber-reinforced composite member from two types of reinforcing fibers having different specific gravities. On the other hand, as a high specific gravity reinforcing fiber, a mixed fiber using a modified fiber having a plurality of needle-like portions extending from a core portion is dispersed in a liquid to prepare a slurry-like molding material, and then the slurry-like molding material is prepared. Inject the material into the mold,
Thereafter, the liquid is removed and the mixed fibers are deposited.

[0007]

1 and 2 show a hybrid fiber molded article 1 for a fiber-reinforced composite member obtained according to the present invention. The fiber molded article 1 is a short fiber ( low fiber) which is a fiber for low specific gravity reinforcement.
2 ) and deformed fiber 3 which is a fiber for high specific gravity reinforcement
And a substantially disk shape.

The short fibers 2 are intended to improve the strength of the fiber-reinforced composite member.
When the length is L and the diameter is D, it has a predetermined length satisfying a relationship of L / D> 1, and in this embodiment, aluminum borate whisker (9Al ₂ O ₃ .2B ₂ O ₃ whisker) ) Is used. The length L of this aluminum borate whisker is 10 to 20 μm, and the diameter D is 0.5 to 3 μm.
μm, specific gravity is 2.93. The deformed fibers 3 are intended to alleviate the strength anisotropy of the fiber-reinforced composite member. As the deformed fibers 3, a plurality extending from the core 4 as shown in FIG. In this example, a tetrapot-shaped one having four needle-like portions 5 is used, and in this embodiment, zinc oxide whiskers (ZnO whiskers) are used. In this zinc oxide whisker, the length of the needle portion 5 from the core portion 4 is 10 to 100 μm, and the specific gravity is 5.78.

In the hybrid fiber molded article 1, the short fibers 2 are randomly dispersed throughout the fiber molded article 1, and the irregular fibers 3 are uniformly dispersed in the aggregate of the short fibers 2. .

Next, a method of forming the hybrid fiber molded article 1 will be described.

FIG. 4 shows a molding die 6 used in the present invention. The molding die 6 is slidably fitted into a mold body 8 having a cavity 7 opening upward. A plurality of drain holes 10 are formed on the bottom surface of the cavity of the mold body 8.
The inlets of the drain holes 10 are covered with a filter 11, and the outlet side is connected to a suction pump 12.

First, a mixed fiber composed of the short fibers 2 and the modified fibers 3 is dispersed in a liquid, in this embodiment, water to prepare a slurry-like molding material.

Next, a predetermined amount of a slurry-like molding material S is injected into the cavity 7 as shown in FIG.

Thereafter, as shown in FIG.
2 and the pressurizing punch 9 is lowered to remove the liquid and deposit the mixed fiber to form the hybrid fiber molded body 1.

During the deposition of the mixed fiber, the irregular fiber 3 having a high specific gravity is converted into the short fiber 2 having a low specific gravity by its needle-like portion 5.
And sedimentation, the hybrid fiber molded body 1 in which the irregular fibers 3 are uniformly dispersed is obtained.

Specific examples of the molding conditions of the fiber molded body 1 are as follows.

Dimensions of the fiber molded body: diameter 86 mm, length 25
mm; slurry-like molding material: water 1000 cc, mixed fiber 68
g (short fiber: 59.6 g, modified fiber: 8.4 g), blended amount of modified fiber: 7% by volume; pressure of pressurizing punch: 30 kg / c
m ² ; suction pressure of suction pump: 100 Torr; drying: 24 hours in cold air, 12 hours in 120 ° C. atmosphere. The blending amount (volume%) of the deformed fiber 3 depends on the volume of the mixed fiber (short fiber 2).
When the volume of the modified fiber 3 is V ₁ and the volume of the modified fiber 3 is V ₂ , it is expressed as (V ₂ / V ₁ ) × 100.

The needle-shaped portion 5 of the modified fiber 3 may be broken during handling or the like. However, if the number of the needle-shaped portions 5 is at least two, there is an effect of embracing the short fiber 2. The effect is improved as the number of the needle-shaped portions 5 increases.

FIG. 6 shows the relationship between the distance from one surface a of the cavity bottom side and the abundance of the modified fibers 3 in the hybrid fiber molded article 1 using 7% by volume of the modified fibers 3. In this case, the dimensions of the fiber molded body 1 are the same as described above. It is clear from FIG. 6 that the use of the modified fibers 3 as the high specific gravity reinforcing fibers allows the modified fibers 3 to be uniformly dispersed.

FIG. 7 shows the relationship between the compounding amount of the modified fibers 3 and the strength difference between the A and B directions in the fiber reinforced composite member. FIG. 8 is an enlarged view of the main part of FIG. The direction A is a direction parallel to the deposition direction as shown in FIG.
The direction indicates a deposition direction as shown in FIG. 1, and thus a direction orthogonal to the A direction. As a matrix forming material, an Al-Si-Cu-Mg-based alloy was used, and a molten metal forging method was applied in manufacturing a composite member. The volume fraction Vf of the fiber molded body 1 in the fiber reinforced composite member is 14%.
It is.

7 and 8, by setting the amount of the modified fiber 3 to be at least 0.3% by volume, the difference in strength between the A and B directions is reduced, and the strength anisotropy is reduced. I understand. The preferable blending amount of the modified fiber 3 for obtaining such an effect is 3% by volume or more.

The amount of the modified fibers 3 is set to 0.3% by volume or more for the purpose of reducing the strength anisotropy of the fiber-reinforced composite member as described above. Since the wear resistance of the fiber 3 is lower than that of the short fiber 2, when the amount of the modified fiber 3 exceeds 55% by volume, the wear resistance of the fiber-reinforced composite member may be impaired. In this respect, the amount of the modified fiber 3 is preferably equal to or less than 55% by volume.

[0023]

According to the present invention, by using the modified fibers having the above-mentioned specific structure as the high specific gravity reinforcing fibers, it is possible to obtain a hybrid fiber molded product in which the modified fibers are uniformly dispersed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a hybrid fiber molded product.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a perspective view of a modified fiber.

FIG. 4 is an explanatory view showing a state in which a slurry-like molding material is injected into a molding die.

FIG. 5 is an explanatory view during the formation of a hybrid fiber molded article.

FIG. 6 is a graph showing the relationship between the distance from one surface of the hybrid fiber molded article and the abundance of modified fibers.

FIG. 7 is a graph showing the relationship between the amount of modified fibers and the difference in strength in both A and B directions in the fiber-reinforced composite member.

FIG. 8 is an enlarged view of a main part of FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hybrid-type fiber molded object 2 Short fiber 3 Deformed fiber 4 Core part 5 Needle-like part 6 Molding mold S slurry-like molding material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-138426 (JP, A) JP-A-1-2422734 (JP, A) JP-A-1-242735 (JP, A) JP-A-2- 61014 (JP, A) JP 3-68090 (JP, B2) (58) Fields surveyed (Int. Cl. ⁷ , DB name) C22C 1/09 D04H 1/00-18/00

Claims (1)

(57) [Claims] 1. A short fiber (2) is used as a low specific gravity reinforcing fiber in forming a hybrid type fiber molded article for a fiber reinforced composite member from two types of reinforcing fibers having different specific gravities.
On the other hand, as a fiber for high specific gravity reinforcement, a mixed fiber using a modified fiber (3) having a plurality of needle-like portions (5) extending from a core portion (4) is dispersed in a liquid to form a slurry-like molding material ( S ) Is prepared, and then the slurry-like molding material ( S ) is poured into a molding die (6), and thereafter, the liquid is removed and the mixed fibers are deposited, whereby a hybrid mold for a fiber-reinforced composite member is prepared. A method for forming a fiber molded body.