JP3171287B2 - Fiber molding for reinforced metal and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber molded product for a reinforced metal which is most suitable for producing a fiber reinforced metal by filling and compounding into a light alloy casting and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a vacuum suction method has been widely practiced as a method for producing an inorganic short fiber molded article. In the vacuum suction method, the inorganic short fibers and a required amount of a binder are uniformly dispersed in a large amount of water to form a slurry, a metal mold for molding is submerged in the slurry, and the slurry is suction-filtered from the inside of the metal mesh to perform a wire mesh. This is a method in which fibers are laminated on the surface of a mold and dried to obtain a molded body.

[0003]

However, in the vacuum suction method, it was difficult to produce a small compact and a solid compact having accurate dimensional accuracy. Furthermore, since the binder was dissolved or dispersed in a solvent such as water, the concentration of the binder was low, and a molded article having sufficient strength to withstand handling could not be obtained. For dehydrating slurry under pressure
A method has been proposed, but similar to the vacuum suction method, slurry
As long as it is in a state, the binder can be dissolved or
And the concentration will be low due to
Is it possible to obtain a molded body with sufficient strength to withstand?
Was.

[0004] In view of the above-mentioned problems of the prior art, the present invention provides a method for producing a fiber molded product for a reinforced metal capable of mass-producing a relatively small molded product with high dimensional accuracy.
Another object of the present invention is to provide a fiber molded product for a reinforcing metal which is solid, has high strength, and has a high porosity.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a fiber for reinforced metal.
Fibers and their manufacture without slurry
Is the way.

The first invention of the present application has a length of 0.01 to 3 mm.
Aluminosilicate fiber, mullite whisker
ー, one kind selected from aluminum borate whiskers or
At least two types of inorganic short fibers, colloidal alumina,
Kind selected from idal silica and colloidal zirconium
Or containing two or more binders, the water content is 5 to 25 weight
% Of the mixture is pressed and dewatered during the pressing.
No dewatering treatment by heating after pressure molding.
The gist of the invention is a method for producing a fiber molded product for a reinforced metal . The second invention of the present application has a length of 0.01 to 3 mm.
Te, Aruminoshi Riketo fiber, mullite whisker, the boron
One or more selected from aluminum phosphate whiskers
Top inorganic short fiber, colloidal alumina, colloidal
One selected from silica, colloidal zirconium or
It is formed of two or more binders and has a porosity of 60 to 95%.
Has a compressive strength of 4.6 kgf / cm ² or more
SUMMARY OF THE INVENTION Furthermore, the third invention of the present application has a length of 0.01 to 3 mm.
Formed of an inorganic short fiber and a binder, and having a porosity of 60 to
It is a molded product of 95%, and 10 to 70 weight
% Mullite whiskers and 30-90% by weight boric acid
Colloidal as binding material using luminium whiskers
Fiber molding for reinforced metal characterized by using alumina
The body is the gist.

[0007]

The aluminum borate whisker used as the inorganic short fiber has a characteristic of largely expanding (spring back) when the pressure is released after press molding. The reason is that the whisker has a tensile strength of 800 kgf / m
This is because the whisker does not break even when pressed because the m ² and the elastic modulus are as large as 40,000 kgf / mm ² .

[0008] Mullite whiskers used as inorganic short fibers tend to have increased bulk density and reduced porosity during press molding. The reason is that the aspect ratio is smaller than aluminum borate whiskers,
This is because the whisker breaks when pressed because the tensile strength and the elastic modulus are small, and the aspect ratio is further reduced.

Therefore, the object of the present invention can be achieved by appropriately using these inorganic short fibers.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

The fiber shaped article for reinforcing metal of the present invention comprises inorganic short fibers having a length of 0.01 to 3 mm and a binder. As the inorganic short fibers, one or two selected from aluminosilicate fibers, mullite whiskers, and aluminum borate whiskers are used. As a binder,
One or two selected from colloidal alumina, colloidal silica, and colloidal zirconium are used. The porosity of the fiber molded body for reinforcing metal is set in the range of 60 to 95%.

According to the method of the present invention for producing a fiber molded product for a reinforced metal, the length is 0.01 to 3 mm, and one or two selected from aluminosilicate fibers, mullite whiskers, and aluminum borate whiskers. A molded article having a desired shape is obtained by pressure-forming a mixture containing the above-mentioned inorganic short fibers and one or two or more binders selected from colloidal alumina, colloidal silica, and colloidal zirconium. At this time, the water content of the mixture is adjusted within the range of 5 to 25% by weight. Thereafter, the molded article is heated and subjected to a dehydration treatment to produce a fiber molded article for reinforced metal.

[0013] By forming a molded body by pressure molding, a solid body having substantially the same dimensions as a mold can be obtained. Further, according to the pressure molding, a binder having a higher concentration can be used as compared with the conventional vacuum suction method, and a molded article having high strength can be obtained.

The aluminosilicate fiber used as the inorganic short fiber is composed of 30 to 60% by weight of Al ₂ O ₃ and 30 to 60% by weight.
60 wt% of SiO _2, an amorphous ceramic fiber composed of 0 to 25 wt% other ingredients. Aluminosilicate fibers generally have heat resistance even at 1200 to 1500 ° C., and exhibit abrasion resistance when Mohs hardness is in the range of 5 to 7.

The mullite whiskers used as the inorganic short fibers are 3Al ₂ O ₃ .2SiO _{2 to} 2Al ₂ O ₃ .S
It is a needle-like crystal having a chemical composition shown in the range of iO ₂ and containing mullite as a main component. The aspect ratio is 10
That is all.

The aluminum borate whiskers to be used as the inorganic short fibers is a compound of aluminum oxide and boron oxide, the chemical composition has a needle-like crystals be _{9Al 2 O 3 · 2B 2 O} 3.

The length of the inorganic short fibers used in the present invention is preferably 0.01 to 3 mm. Fiber length is 0.01mm
That is, if it is shorter than 10 μm, the density of the molded body increases and the porosity decreases. On the other hand, if the length of the fiber is longer than 3 mm, the filling property into the press mold becomes poor.

The porosity of the molded product is preferably 60 to 95%. When the porosity is smaller than 60%, the metal filling property is deteriorated.
Conversely, if the porosity exceeds 95%, the strength of the fiber reinforced metal cannot be sufficiently increased.

The mixing ratio of mullite whiskers and aluminum borate whiskers is such that the ratio of mullite whiskers is 10 to 70% by weight, more preferably 20 to 50% by weight. If the aluminum borate whisker exceeds 90% by weight, the expansion (spring back) becomes too large when the pressure is released after press molding. On the other hand, if the mullite whisker exceeds 70% by weight, the bulk density increases and the porosity becomes too small.

Hereinafter, Examples 1 to 6 will be described.

Mullite whiskers and aluminum borate whiskers were blended at a predetermined ratio, mixed with a stirrer until uniform, a predetermined alumina sol was added, and the mixture was further mixed for several minutes. The mixture was filled in a mold of a press molding machine and press-molded at a pressure of 50 to 100 kgf / cm ² . After drying in a drier, heat treatment was performed at 1200 ° C. for 3 hours.
To 6 were obtained. And Examples 1 to
Compressive strength and porosity of the fiber molded product for reinforced metal No. 6 were measured. Table 1 shows the mixing ratio of the mixture thus prepared and the measurement results.

[0022]

[Table 1] As a method for filling the molded body with metal according to the present invention, generally used molten forging, low pressure casting, die casting, and the like can be employed. Here, the metal to be filled is aluminum,
Magnesium, copper, zinc, tin and alloys containing these as main components can be used.

The fiber reinforced metal can be used, for example, for sliding parts of various machines to improve specific strength and abrasion resistance and to reduce weight.

[0024]

According to the fiber molding for reinforced metal and the method for producing the same according to the present invention, the slurry
Since it is manufactured without being in a state, a relatively small formed body can be easily produced with high dimensional accuracy, and a solid body with high strength and high voidage can be obtained.

Further, by applying the molded product according to the third aspect, as compared with the conventional silicon carbide whisker or fiber-reinforced metal to which aluminum fiber is applied, the abrasion characteristics are excellent and the aggressiveness to the counterpart material is small. A fiber reinforced metal can be obtained.

Continuation of the front page (56) References JP-A-5-213681 (JP, A) JP-A-2-156030 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B28B 3 / 02

Claims (3)

(57) [Claims] 1. One or two or more inorganic short fibers selected from aluminosilicate fibers, mullite whiskers, and aluminum borate whiskers having a length of 0.01 to 3 mm, colloidal alumina, colloidal silica,
Includes a selected one or two or more of the binder from the colloidal zirconium, moisture content mixture is 5 to 25% by weight pressure-molding, without dehydration during the pressure molding, after pressing <br/> A method for producing a fiber molded product for a reinforced metal, wherein a dehydration treatment is performed by heating. 2. A length of 0.01 to 3 mm, one or two or more inorganic short fibers selected from aluminosilicate fibers, mullite whiskers, and aluminum borate whiskers, colloidal alumina, colloidal silica,
Formed by one selected from colloidal zirconium or two or more kinds of the binder, porosity of Ri 60% to 95% der, or
One, reinforced metal fibers molded compressive strength, characterized in der Rukoto 4.6 kgf / cm ² or more. 3. An inorganic short fiber having a length of 0.01 to 3 mm.
And a molded product formed of a binder and having a porosity of 60 to 95%
A fiber molded body for a reinforcing metal, wherein mullite whiskers of 10 to 70% by weight and aluminum borate whiskers of 30 to 90% by weight are used as inorganic fibers and colloidal alumina is used as a binder.