JPH10306332A - Production of molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing moldings which are not simple in shapes by a near-net method. SOLUTION: A mold 3 having an air permeable surface 2 is immersed into a slurry 1 prepd. by dispersing a reinforcing material and a binder into liquid. While the mold 3 is pulled up from the liquid surface of the slurry 1 after suction for a specified time, suction is executed to form adsorption layers 4b varying in thicknesses. The moldings having collars at sleeves may be produced if a surface of the direction orthogonal with an axis is formed on the air permeable surface 2 of the mold 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a porous compact for producing a metal matrix composite (MMC, metal matrix compound).

[0002]

2. Description of the Related Art As a method for producing a metal-based composite material in which inorganic fibers such as ceramics, metals, and intermetallic compounds, whiskers, and particles are compounded in a light alloy such as aluminum or magne, a liquid phase method is used. General. In other words, a porous compact is manufactured in advance using inorganic fibers, whiskers, particles, etc., placed in a mold, poured with a melt of a light alloy, and pressurized to form a light alloy in the void of the compact. To obtain a metal-based composite material. Conventionally, as a method for producing this porous molded body, as disclosed in JP-A-62-116738, reinforcing materials (inorganic fibers, whiskers such as the above-mentioned ceramics, metals and intermetallic compounds) are generally used. , Particles) and a binder having a fine mesh such as a wire mesh immersed in a slurry in which a binder for maintaining the shape of the molded body is dispersed in water, and the slurry is sucked from the inside of the mold. By doing so, so-called suction molding, in which a reinforcing material and a binder are attached to a mesh portion on the surface of a mold, is used.

[0003]

However, the suction molding method can be manufactured without any problem with a simple shape such as a cylindrical shape in which the outer diameter and the inner diameter are parallel to each other. When the wall pressure changes in the axial direction) or when the shape is complicated (for example, in the case of a flanged shape), a method is employed in which the material is formed into a thick wall and then subjected to cutting after forming to obtain the final shape. Therefore, there was a problem that the raw material yield was poor. An object of the present invention is to use a near net to form a molded article having a more complicated shape than a cylindrical shape having an outer diameter and an inner diameter that are parallel, such as a molded article having a different inclination of an outer diameter and an inner diameter and a molded article with a flange. The net is close to the final shape,
The present invention is intended to provide a manufacturing method for forming into a state where little processing is required.

[0004]

The present invention to achieve the above object is as follows. (1) A step of immersing a mold having a gas permeable surface on at least a part of its surface in a slurry in which the reinforcing material is dispersed in a liquid, and applying a predetermined time to apply a layer of the reinforcing material to the gas permeable surface. Forming a predetermined thickness, and then forming a reinforcing material layer whose thickness varies depending on the position on the reinforcing material layer by performing suction while pulling up a mold from the slurry. How to make the body. (2) The method for producing a molded article according to (1), wherein the molded article is produced using a molding die whose air-permeable surface extends in the axial direction of the molding die. (3) The molded body according to (1), wherein the molded body is manufactured using a molding die having a portion where the air-permeable surface extends in the axial direction of the molding die and at least a portion orthogonal to the axial direction of the molding die. Production method.

[0005] The manufacturing method (1) includes a step of performing suction while pulling up the molding die from the slurry, so that the molded body formed in this step has a thickness in the pulling direction (axial direction of the molded body). Thus, it is possible to manufacture a molded body having a portion whose inner diameter surface and outer diameter surface are not parallel to each other. When the strength of the molded body is insufficient with only the fibers, it is desirable to include a binder in the slurry. In the manufacturing method (2), since the air-permeable surface extends in the axial direction, a sleeve-shaped molded body having a tapered inner diameter, a straight outer diameter, or a straight inner diameter and a tapered outer diameter can be manufactured. . Further, depending on the manner of adjusting the lifting speed, the thickness can be changed not only linearly but also in a curved manner. In the manufacturing method of the above (3), since the air-permeable surface has a portion extending in the axial direction and a portion orthogonal thereto, the sleeve has a tapered inner diameter, a straight outer diameter or a straight inner diameter, and a tapered outer diameter. A molded article having a flange at one end can be manufactured.

[0006]

FIG. 1 shows a method for manufacturing a molded article according to a first embodiment of the present invention, FIG. 2 shows a method for producing a molded article according to a second embodiment of the present invention, and FIG. FIG. 4 shows a method for producing a molded article according to the third embodiment of the present invention, and FIG. 4 shows a method for producing a molded article according to the fourth embodiment of the present invention. Portions common to all embodiments of the present invention are denoted by the same reference numerals throughout all embodiments of the present invention.

First, portions common to all embodiments of the present invention will be described with reference to, for example, FIG. The method of manufacturing the molded body 4 according to any of the embodiments of the present invention also includes (1) a molding die 3 having a gas-permeable surface 2 at least in part of a surface in a slurry 1 in which a reinforcing material and a binder are dispersed in a liquid. And (2) performing suction for a predetermined period of time so that the air permeable surface 2
Forming a reinforcing material and binder layer 4a to a predetermined thickness, and (3) thereafter, performing suction while pulling up a mold from the slurry to further increase the thickness on the reinforcing material and binder layer 4a depending on the position. Changing reinforcement and binder layers 4
forming b.

The reinforcing material comprises inorganic fibers, whiskers, and particles such as ceramics, metals, and intermetallic compounds. The ceramic may be, for example, alumina short fiber (trade name: Safir, manufactured by ICI, containing 95% alumina, 5% silica) or alumina / silica short fiber (manufactured by Isolite Industries, trade name: Alsilon, 50% alumina) (Containing 50% of silica). Metal
Stainless steel fiber, metal silicon powder, nickel powder and the like can be used. As the intermetallic compound, an iron-molybdenum compound or the like can be used. The binder is obtained by taking any one of an inorganic binder, an organic material binder, and a mixture of both of them as a liquid (for example, water). The inorganic binder is colloidal silica, alumina sol or the like, and the organic binder is cationized starch or the like. The cationized starch disappears when the molded body is fired.
The slurry 1 is obtained by adding about 5 grams of reinforcing material to 1 liter of a liquid (for example, water). In order to maintain a state in which the reinforcing material and the binder are uniformly dispersed, a stirrer 5 such as a rotary blade is used. It is constantly stirred.

A molding die 3 immersed in the slurry 1 has a gas permeable surface 2 on a part of its surface. The gas permeable surface 2 is formed on a punched metal to maintain its shape and to have gas permeability. And a mesh material such as a fine wire net wound at least one time. The portion of the molding die 3 that is not the gas permeable surface 2 is made of a metal plate without holes (for example, a stainless steel plate). The mold 3 is a hollow mold and the inside of the mold is sucked, and the slurry is sucked into the mold together with the liquid from outside the mold.
When the slurry passes through the gas permeable surface 2, the fibrous or particulate reinforcing material and the binder are filtered by a mesh and adhere and deposit on the outer surface of the gas permeable surface 2, so that the layers 4 a and 4 b can be formed.

The suction is performed by suctioning for a certain period of time to form a layer 4a having a uniform thickness substantially uniformly over the entire area of the gas permeable surface 2 of the mold 3, and thereafter, the mold 3 is removed from the slurry while being sucked. Forming the layer 4b having a different thickness depending on the position by gradually pulling it up. In this case, by controlling the pulling speed, an arbitrary layer thickness 4b can be obtained.
For example, an inner diameter taper, an outer diameter straight, or an inner diameter straight, an outer diameter tapered surface can be formed. In a normal case, after the molded article is formed, the mold is released from the molded article. Therefore, it is convenient to taper the inner diameter. At this time, the liquid level of the slurry 1 also
Since it is lowered by suction, the pulling speed of the mold 3 is
It must be determined in consideration of the lowering speed of the liquid level of the slurry 1.

The mold 3 that has been completely lifted is further sucked for a certain period of time to dewater the layer 4 (the sum of the layer 4a and the layer 4b). The layer 4 that becomes the molded body 4 obtained as described above is still slightly moist and is soft. Therefore, the mold is removed at this stage (the mold 3 having a mesh and the layer 4 are separated).
Then, since the shape of the layer 4 is lost, the layer 4 is dried (for example, at 120 ° C. × 1) without being removed from the mold 3.
hr) and demold after drying. Thereafter, in order to sufficiently bring out the binding force of the binder, the layer 4 is fired at a higher temperature (for example, 400 to 1300 ° C. × 30 min to 1 hr),
A molded body 4 is obtained. The molded body 4 is porous and has a non-simple shape such as a sleeve whose inner and outer diameters are not parallel and a sleeve having a flange. Thereafter, if necessary, a small amount of cutting is performed to obtain a molded body 4 having a final shape. For example, in the case of the sleeve-shaped molded body 4 having an inner diameter taper and an outer diameter straight, the inner diameter may be straightened at the time of cutting to form a molded body 4 having a thickness of about 3 to 4 mm. Alternatively, depending on the application, it may be better to use the inner diameter taper without processing.

The molded body 4 is used for producing a metal matrix composite (MMC) by a liquid phase method. That is, the porous molded body 4 is placed in a mold, a molten metal of a light alloy such as aluminum or magnesium is poured, and the molten metal is impregnated into the molded body to obtain the MMC. This sleeve can be used as a cylinder liner of an aluminum cylinder block of an internal combustion engine. By using the sleeve instead of a cast iron liner, the weight of the cylinder block can be reduced. In addition, because the cylinder block base material has good fusion with aluminum, the distance between liners can be reduced as compared with the case of cast iron liners, thereby reducing the overall length and weight of the internal combustion engine, or changing the overall length. Without increasing the bore diameter, the engine output can be increased.

Next, parts unique to each embodiment of the present invention will be described. In the first embodiment of the present invention, as shown in FIG. 1, the mold 3 is a male mold and has a gas permeable surface 2 on the outer peripheral surface. The molding die 3 is immersed in the slurry 1 with the axial direction being vertical as shown in step A of FIG. The portion of the air permeable surface 2 of the mold 3 is a tapered surface whose diameter decreases as the inner diameter surface approaches the lower end. As shown in Step B of FIG. 1, a layer 4 a having the same thickness is formed over the entire permeable surface 2 in a first suction step performed while the entire permeable surface 2 is immersed in the slurry. For example, 10
Hold suction for 20 seconds to obtain a layer thickness of 5-7 mm. Then, as shown in step C of FIG. 1, in a second suction step performed while pulling the gas-permeable surface 2 out of the slurry, a layer 4b whose thickness is increased toward the lower end is formed, and the layer 4b is formed on the layer 4a. It is formed. As a result, a sleeve-shaped layer 4 having a straight outer diameter and a tapered inner diameter and containing moisture is obtained. For example, when the height of the mold is 160 mm, it is pulled up in 20 to 30 seconds (at a speed of 0.5 to 0.8 cm / sec). Step D in FIG. 1 shows a completely pulled state. Thereafter, the layer 4 is dried, demolded, and fired to obtain a molded body 4 having an inner diameter taper (the lower end is reduced in diameter) and an outer diameter straight as shown in Step E of FIG. If the air permeable surface 2 of the mold 3 is straight, a tapered shaped body 4 is obtained in which the inner surface is straight and the outer diameter increases as the outer surface goes down.

In the second embodiment of the present invention, as shown in FIG. 2, the molding die 3 is a female die, and has a gas permeable surface 2 on its inner peripheral surface. The molding die 3 is immersed in the slurry 1 with the axial direction being vertical as shown in step A of FIG. The portion of the air-permeable surface 2 of the mold 3 is a straight surface extending parallel to the axis. As shown in Step B of FIG. 2, a layer 4a having the same thickness is formed over the entire permeable surface 2 in a first suction step performed in a state where the entire permeable surface 2 is immersed in the slurry. Next, as shown in step C of FIG. 2, a second step is performed while pulling the gas permeable surface 2 out of the slurry.
Is formed, a layer 4b whose thickness becomes thicker toward the lower end is formed, and the layer 4b is formed on the layer 4a. Step D in FIG. 2 shows a completely pulled state. Thereafter, the molded body 4 is dried, removed from the mold, and fired to obtain a molded body 4 having an inner diameter taper (the lower end is reduced in diameter) and an outer diameter straight as shown in Step E of FIG. Also in the case of this embodiment, it is possible to make the inside diameter straight and the outside diameter taper (the outside diameter of the lower end is large) by making the gas permeable surface 2 taper with a larger inside diameter toward the bottom.

In the third embodiment of the present invention, as shown in FIG. 3, the molding die 3 is a male die, and its outer surface has a portion 2a extending in the axial direction of the molding die and a portion 2b extending in a direction perpendicular thereto. And a gas permeable surface 2 comprising: The molding die 3 is shown in FIG.
As shown in the step A, the substrate is immersed in the slurry 1 with the axial direction being vertical. Portion 2a of air-permeable surface 2 of mold 3
Is a tapered surface whose diameter decreases as the inner diameter surface approaches the lower end. As shown in step B of FIG.
In a first suction stage, which is carried out entirely in the slurry, a layer 4a of the same thickness
Is formed. Next, as shown in Step C of FIG. 3, in a second suction step performed while pulling the gas-permeable surface 2 out of the slurry, a layer 4b whose thickness is increased toward the lower end is formed, and the layer 4b is formed on the layer 4a. It is formed. Thus, a sleeve-like layer 4 containing an outer diameter straight, an inner diameter taper, and a flange (flange) and containing moisture is obtained. Step D in FIG. 3 shows a completely pulled state. Thereafter, the layer 4 is dried, removed from the mold, and fired. As shown in step E of FIG. 3, a molded body 4 having an inner diameter taper (lower end is reduced), an outer diameter straight, and a flange (flange) at the upper end. Get. In the illustrated example, the flange is shown extending outward in the radial direction. However, the flange may extend inward in the radial direction. In this embodiment, the air-permeable surface forming the flange includes a portion 2a extending in the axial direction and a portion 2a orthogonal thereto.
b, but also as shown in FIG.
2 extending in the axial direction and facing the portion 2a
c may be provided. In this case, the presence of suction surfaces in three directions eliminates variations in the shape of the flange portion.

In the fourth embodiment of the present invention, as shown in FIG. 4, the molding die 3 is a female die, and its inner surface has a portion 2a extending in the axial direction of the molding die and a portion 2b extending in a direction perpendicular thereto.
And a gas permeable surface 2 comprising: As shown in step A of FIG.
Immersed in. The portion 2a of the air permeable surface 2 of the mold 3 is
It is a straight surface extending parallel to the axis. As shown in Step B of FIG. 4, a layer 4a having the same thickness is formed over the entire permeable surface 2 in a first suction step performed in a state where the entire permeable surface 2 is immersed in the slurry. Next, as shown in step C of FIG. 4, in a second suction step performed while pulling the gas-permeable surface 2 out of the slurry, a layer 4b whose thickness is increased toward the lower end is formed, and the layer 4b is formed on the layer 4a. It is formed. Step D in FIG. 4 shows a completely pulled state. Thereafter, the molded body 4 is dried, demolded, and fired to obtain a molded body 4 having an inner diameter taper (the lower end is reduced in diameter), an outer diameter straight, and a flange (flange) at the upper end, as shown in Step E of FIG. In the illustrated example, the flange is shown extending outward in the radial direction. However, the flange may extend inward in the radial direction.

In the above description, an example in which the outer diameter is straight or a straight with a flange, and the inner diameter is tapered has been described. However, while the mold is being pulled up, the mold is temporarily lowered at the same speed as the stopping liquid level, and thereafter, By pulling it up again, it is possible to produce a molded product having a stepped outer diameter in the male mold. In the above description, the thickness of the molded body is changed by selecting the pulling speed of the molding die. However, the thickness of the molded body is changed even when the pulling speed of the molding die is selected and the suction pressure is changed. You may.

[0018]

According to the method of manufacturing a molded article according to claim 1,
Since there is a step of performing suction while lifting the mold from the slurry, the thickness of the molded body changes in the pulling direction (axial direction of the molded body) in the molded body formed in the process, and the inner diameter surface and the outer diameter surface are changed. Moldings having non-parallel parts can be produced. According to the method of manufacturing a molded article of the second aspect, since the air-permeable surface extends in the axial direction, a sleeve-shaped molded article having a tapered inner diameter, a straight outer diameter, or a straight inner diameter and a tapered outer diameter is manufactured. can do. Further, by changing the pulling speed, it is possible to manufacture a molded body whose wall thickness changes in a curve. According to the method for manufacturing a molded article of the third aspect, since the air-permeable surface has a portion extending in the axial direction and a portion orthogonal thereto, the inner diameter is tapered, the outer diameter is straight, or the inner diameter is straight, and the outer diameter is reduced. Can produce a molded body having a tapered sleeve and a flange at one end.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a cross-sectional view illustrating a molding method according to a first embodiment of the present invention in the order of steps.

FIG. 2 is a cross-sectional view illustrating a molding method according to a second embodiment of the present invention in a process order.

FIG. 3 is a cross-sectional view showing a molding method according to a third embodiment of the present invention in a process order.

FIG. 4 is a cross-sectional view illustrating a molding method according to a fourth embodiment of the present invention in the order of steps of the method.

FIG. 5 is a cross-sectional view of a molded article to be manufactured according to the present invention having a flange 3
It is sectional drawing of a shaping | molding die when a surface has a gas-permeable surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slurry 2 Air-permeable surface 2a Portion extending in the axial direction 2b Portion extending in the direction orthogonal to the axial direction 3 Mold 4 Mold 4a layer 4b layer 5 Stirrer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiaki Kajikawa 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Automobile Co., Ltd. (72) Inventor Tatsuro Sano 7 Hagiyama Mukaiyama, Ojiwa-cho, Hoei-gun, Aichi Prefecture Isolite Industrial Co., Ltd. In-house (72) Inventor Kazuaki Kashimoto 7-member, Mukoyama, Hagi-ji, Owa-cho, Hohan-gun, Aichi Prefecture (72) Inventor Yasufumi Kinoshita 7-size, Makiyama, Hagi-shi, Otowa-cho, Hohan-gun, Aichi Inside

Claims (3)

[Claims] 1. A step of immersing a mold having a gas-permeable surface on at least a part of a surface thereof in a slurry in which a reinforcing material is dispersed in a liquid; A step of forming a layer having a predetermined thickness, and thereafter, a step of forming a layer of the reinforcing material whose thickness changes depending on the position further on the layer of the reinforcing material by performing suction while pulling up the mold from the slurry. A method for producing a molded article. 2. The method for producing a molded article according to claim 1, wherein the molded article is produced using a molding die whose air-permeable surface extends in the axial direction of the molding die. 3. The molding according to claim 1, wherein the molding is manufactured using a molding die having a portion where the air-permeable surface extends in the axial direction of the molding die and at least a portion orthogonal to the axial direction of the molding die. How to make the body.