JPS60206524A - Extrusion forming method of composite material - Google Patents

Abstract

PURPOSE:To prevent wear of a die and to improve the quality of a product by extruding indirectly composite billets composed of aluminum (alloy) and ceramic material contained in a cylindrical container made of aluminum (alloy). CONSTITUTION:Composite billets 2 are prepared by compressing a mixture of ceramic material and power of aluminum (alloy) or by soaking the ceramic material in molten metl of aluminum (alloy). The billets 2 are contained densely in a cylindrical container 4 made of aluminum (alloy) and covered, and charge in a container 10 of a specified indirect extruding device. Then, the billets are extruded indirectly preventing occurrence of relative displacement between the container 10 and container 4. Thus, a composite material 20 in which the container 4 became the skin part 22 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of extrusion molding a composite material, and more particularly to a method of extrusion molding a desired composite material from a composite billet made of a ceramic material and aluminum or an alloy thereof.

In the past, various studies have been carried out on forming elongated, predetermined shaped objects from composite materials of ceramic and aluminum or their alloys. A composite billet made of the material is inserted as is into the container of an extruder, and extrusion molding is attempted using a direct extrusion method.

However, in the method of directly extruding such a composite billet as it is, since the composite billet itself is very hard and contains ceramic with poor workability, there is a problem that the die bearing part may be worn out or damaged during extrusion. Moreover, during extrusion, the composite material formed has problems with roughening and cracking of the surface. Furthermore, in this direct extrusion method, friction occurs between the outer periphery of the billet and the container, so the flow of material is faster at the center of the billet than at the outer periphery, resulting in fir tree-like cracks. Because of the inherent problems and the occurrence of cracks, the extrusion speed could not be increased, making it extremely difficult to improve productivity.

The present invention has been developed against the background of the above, and its purpose is to extrude a composite material from a composite billet made of ceramic and aluminum or an alloy thereof. , while preventing wear and damage to the extrusion die hair ring part.
The object of the present invention is to provide a method that can effectively prevent surface roughening and cracking of a composite material (product) after extrusion, improve its quality, and further improve its productivity.

That is, in order to achieve such an object, the present invention provides a composite billet made of a ceramic material and aluminum or an alloy thereof, which is tightly housed in a cylindrical container made of aluminum or an alloy thereof, and then covered with a lid. By loading the containers of the extrusion device and indirectly extruding them through a predetermined chair in such a manner that no relative displacement is substantially induced between the containers and the binding receptacle, said containers become skin parts. Further, the present invention is characterized in that an extrudate having a predetermined shape is formed from the composite billet.

As described above, according to the method of the present invention, a predetermined composite billet made of a ceramic material and aluminum or an alloy thereof is extruded by an indirect extrusion method, and the composite billet is housed in a container and extruded. As a result, the dead metal portion becomes minute and the container covering the outer surface of the composite billet is simultaneously extruded along with the composite billet, remaining as the skin of the extruded material (product) and forming its surface. Therefore, unlike extruded products such as the conventional direct extrusion method, in which the container material enters the composite billet during the extrusion operation, problems such as entrainment of the skin do not occur, and therefore, The extruded product can be easily removed by machining such as surface cutting, thereby making it possible to advantageously obtain the desired elongated composite material.

In addition, since the composite billet is extruded with its surface covered with a cylindrical container made of aluminum or its alloy, which is a material with good workability, the bearing part of the extrusion die is There is no contact with the ceramic materials that make up the composite billet, and therefore,
Wear and damage to such extrusion dies can be effectively prevented, and the surface roughness and cracking of the composite material due to friction between the die and the molded composite material can also be prevented by the presence of the skin made of such container material. In addition, this indirect extrusion method reduces the difference in material flow between the billet center and the outer periphery, making it possible to effectively prevent Cracks and the like can also be effectively suppressed.

Furthermore, since problems such as die wear and cracking of the extruded composite material can be effectively resolved, it is possible to increase the extrusion speed, thereby significantly improving productivity. It became.

By the way, the composite billet made of a ceramic material used in the present invention, such as powder, long fibers, short fibers, whiskers, etc. and aluminum or an alloy thereof, has -i a combination of such a ceramic material and aluminum or an alloy powder thereof. A cylindrical compression-molded body obtained by compression-molding a mixture, but also a cylindrical compression-molded body obtained by a molten metal forging method in which a predetermined molded body of a ceramic material is impregnated with molten aluminum or its alloy are also suitable. It can be used for. The ceramic material constituting such a composite billet is used in an appropriate size and mixed with aluminum or its alloy, but in general, in powder form, the size is 0.1 μm.
In the case of long fibers, the diameter is about 0.1 μm to 100 μm, and in the case of short fibers, the size is 0.1 μm-1.
00 μm, length: 1 μm to 50+++*, and for whiskers, thickness: 0.1 μm
They will be used in dimensions of approximately 10 II m and length slum of approximately 100 μm.

Furthermore, this ceramic material typically has a capacity of 50
% or less, especially about 10 to 30% in the billet.

Then, such a composite billet made of ceramic material and aluminum or its alloy is tightly housed in a cylindrical container made of predetermined aluminum or its alloy and covered with a lid, so that its entire surface is completely coated. It is considered a state.

For example, an example is shown in FIGS. 1 and 2(a) and (b), in which a cylindrical composite billet 2 is formed by a cylindrical body 4 made of aluminum or its alloy.
The composite billet 2 is inserted into the inside and its both ends are covered with a disc-shaped lid 6 made of a similar aluminum material, so that the entire surface of the composite billet 2 is completely covered with aluminum or its alloy material. This results in a structure that is similar to the above.

Note that as the material for the cylindrical body 4 and the lid body 6, any aluminum or alloy thereof can be used, but it is particularly recommended to choose a material with good extrudability such as A6063 or A1050. desirable. The wall thickness of the cylindrical wall of the cylindrical body 4 is generally about 1 to 5 members, and its axial length is approximately equal to the sum of the length of the composite billet 2 and the thickness of the lid 6. It looks like this.

The lid 6 that covers both ends of the cylindrical body 4 is generally about 1 to 5 mm thick, and its outer diameter is 0.2 to 0.5 mm thicker than the inner diameter of the cylindrical body 4. - It is made to be somewhat smaller. This is to facilitate fitting of the lid 6 into the end portion of the cylindrical body 4 and to enable gas (mainly air) within the cylindrical body 4 to be discharged to the outside during extrusion.

Furthermore, the composite billet 2 charged into the container composed of the cylindrical body 4 and the lid 6 is made such that the surfaces of the cylindrical body 4 and the lid 6 are adjusted to prevent eccentricity of the skin after extrusion. They will be inserted and positioned closely so that the clearance between them is as small as possible. In general, the clearance between them will be less than or equal to Q, 5 +*@. In addition, after inserting the composite billet 2 into the cylindrical body 4 and covering both ends with the lid 6, a clearance portion between the end of the cylindrical body 4 and the lid 6 is used to fix them. are welded at multiple locations (here, three locations). In addition, in FIG. 2, 8 is the welded portion.

The composite billet 2 thus tightly housed within the cylindrical body 4 is then subjected to 300 m
It will be preheated to a temperature of ~500°C. The heating temperature of this heat treatment 2 is generally the preheating temperature of the aluminum base material before extrusion. Then, the containers (4, 6) containing the composite billet 2 preheated in this manner are loaded into the billet loading hole 12 of the container 10 of a predetermined indirect extrusion device, as shown in FIG. 3, for example. Furthermore, a die 14 is preset in the billet loading hole 12 to give the desired extruded shape of the composite material. Then, the loaded composite billet 2 container (4, 6) is pressurized by the stem 18 via the press plate 16, and extrusion is started.

During this pressurized extrusion, the container IO is moved at the same speed as the stem 18 in the extrusion direction indicated by the arrow by a moving mechanism driven separately as shown in the figure, thereby opening the billet loading hole 12 of the container 10. Indirect extrusion is carried out in such a way that virtually no relative displacement is induced between the inner surface and the outer surface of the billet container, in particular the cylinder 4.

Therefore, a container (4) containing such a composite billet 2 is used.
, 6), no frictional force acts between the inner surface of the billet loading hole 12 of the container IO, and the abutting portion between the die 14 and the front end of the billet storage container pressed by the die 14 The dead metal portion formed in the billet storage container becomes minute, thereby preventing the lid 6 and the cylindrical body 4 constituting the billet storage container from being mixed into the composite billet 2 that is deformed by the pressing force. The constituent materials of the cylindrical body 4 and the lid 6 remain as they are on the entire surface of the composite material 20 (extruded material) as the skin 22 that is extruded from the die 14, thereby making the composite material 20 without any involvement of the skin 22. It is possible to obtain the desired results. In addition,
The skin 22 covering the surface of this composite 20 can be easily removed by suitable machining, e.g. surface milling, etc., thereby allowing the desired shape of the ceramic material and the aluminum Alternatively, a long composite material 20 of a predetermined shape made only of the composite material 20 or its alloy can be taken out.

Moreover, according to the method of the present invention, the billet loading hole 12
Since there is no relative displacement between the surface and the billet storage container (4, 6) and no frictional force acts, the difference in material flow between the billet center and the outer periphery is small, and therefore the fir In addition, a billet storage container, that is, a cylindrical body 4 and a lid 6 are interposed between the composite billet 2 and the billet loading hole 12 or the die 14, so that main-shaped cracks can be prevented. Since the composite billet 2 is subjected to extrusion molding, problems such as wear and tear of the extrusion die 14 and surface roughening and cracking of the resulting composite material 2o can be effectively solved.

Note that the present invention is not to be construed as being limited to the above-mentioned specific examples (and various modifications and changes may be made based on the knowledge of those skilled in the art without departing from the spirit of the present invention).
It goes without saying that modifications, improvements, etc. can be made to the invention, and that it also includes such embodiments.

For example, a container for accommodating the upper composite billet 2 is composed of a cylindrical body 4 and two disc-shaped lids 6.6 fitted into both ends of the cylindrical body 4. Of course, instead of this, a cylindrical body with a bottom may be used, and a single lid body may be combined with the cylindrical body. Furthermore, the elongated composite material 20 extruded from the die 14 generally has a round bar shape, but may have any other cross-sectional shape.

Furthermore, even in the indirect extrusion method, instead of moving the container 10 and stem 18 at a constant speed as in the previous example, the container 10 and stem 18 are fixed and the die 14 is pressed toward the stem 18. It is also possible to adopt a method in which the die 14 is moved to the left in FIG. 3.

In addition, the composite material obtained according to the method of the present invention can be used as it is (
In addition to being used with the skin 22 still attached (with the skin 22 still attached), it can also be used with the skin removed as described above, and furthermore, the extruded composite material may be subjected to appropriate heat treatment or sintering. Operations such as the following may be added as necessary.

[Brief explanation of drawings]

FIG. 1 shows an exploded view of a container containing a composite billet used in the present invention, FIG. 2(a) is a vertical cross-sectional view of such a composite billet storage container, and FIG. 2(b) is a left side view thereof, and FIG. 3 is a cross-sectional explanatory view showing one form of indirect extrusion according to the present invention. 2: Composite billet 4: Cylindrical body 6: Lid body 8: Welding part 10: Container 12: Billet loading hole 14: Dice
16: Push plate 18: Stem 2o: Composite material 22: Skin Applicant: Sumitomo Light Metal Industries, Ltd.

Claims (3)

[Claims] (1) A composite billet made of a ceramic material and aluminum or its alloy is tightly housed in a cylindrical container made of aluminum or its alloy and covered with a lid, and then loaded into a container of a predetermined indirect extrusion device, and then the container is and a billet storage container by indirect extrusion through a predetermined die in a manner that substantially no relative displacement is caused between the composite billet and the billet storage container, thereby forming an extrudate of a predetermined shape of the composite billet, with the container serving as a skin part. A composite material extrusion molding method characterized by: (2) The extrusion molding method according to claim 1, wherein the composite billet is a compression molded body obtained from a mixture of a ceramic material and aluminum or its alloy powder. (3) The extrusion molding method according to claim 1, wherein the composite billet is obtained by impregnating a ceramic material with a predetermined molten aluminum or alloy thereof using a molten metal forging method.