JPS60208401A - Production of seamless hollow material made of powder material - Google Patents

Abstract

PURPOSE:To obtain effectively a long-sized seamless hollow material from a powder material by sealing the compressed powder material formed by compression molding in a jig into a cylindrical vessel, loading the vessel in a container and subjecting the material to indirect mandrel extrusion. CONSTITUTION:A mixture composed of metallic powder, etc. is packed into a jig such as a rubber vessel 8 or the like contg. an arbor 2 and the jig is compressed to form a hollow compressed powder material 24. The compressed material 24 is contained tightly into an annular cylindrical vessel and is heated to evaporate moisture, etc. and is subjected to evacuation to a vacuum to form a hollow billet 38 for extrusion. Such billet 38 is loaded into the billet-loading hole 42 of a container 40. A mandrel 48 is inserted and positioned into the hollow part of the billet 38 and the billet 38 is pressurized via pressure plate 46 by a stem 50 by which the billet is subjected to indirect mandrel extrusion. The seamless hollow exstrudate having the torus-shaped cylindrical vessel as the skin part is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a seamless hollow material made of a powder material, and in particular to extruding a powder material by indirect mandrel extrusion to effectively produce a long seamless hollow material. It is about the method.

Forming a long, predetermined shaped object from a powdered material such as a metal powder such as aluminum or its alloy powder, or a mixture formed by adding a ceramic material to the metal powder is as follows:
This has traditionally been considered extremely difficult, and it has been recognized that various problems are inherent in not only extrusion processing methods but also other processing methods.

For example, compression molding, which has traditionally been used as a means of molding powdered materials, is generally carried out using a double-acting press with a built-in mold, and presses from one direction. Therefore, it is extremely difficult to form long objects (long objects), and it is not easy to form compressed objects of irregular shapes other than cylinders, rectangles, and square blocks. Even if you try to process the molded product after it has been sintered, there is a problem in that because it is already hardened, a huge amount of processing force is required or only a very small degree of processing can be achieved. Since material i is highly brittle, its processing is also extremely difficult.

For this reason, the applicant of this application has previously filed Japanese Patent Application No. 54-39030.
No. 1400 (Japanese Unexamined Patent Publication No. 1400), we proposed a new extrusion processing method for powdered materials. In other words, after filling powdered materials into capsules made of metal material prepared in advance and pre-compressing them, is an extrusion processing method for powdered materials, which is characterized by deaerating and sealing such capsules and extruding them using a hydrostatic extrusion method. Although it became possible to form elongated objects of various shapes arbitrarily from powdered materials, this method was very difficult to form into special shapes such as hollow extruded materials such as seamless pipes. It is not easy to form t-■.

The HR invention was made against this background, and its purpose is to provide a method for advantageously manufacturing seamless hollow materials from powdered materials, and Another purpose is to advantageously form a hollow compressed powder material for extrusion, which is then housed in an annular billet container to form a hollow billet. The purpose of the present invention is to provide a method for manufacturing hollow materials, especially pipes, with good quality.

In order to achieve the above object, the method for producing a seamless hollow material made of powder material according to the present invention has the following advantages: (b) storing the hollow compression dynamic forming jig filled with the predetermined powder or mixture in a pressurized container that can be pressurized with high-pressure liquid; (c) compressing the jig by applying a predetermined high-pressure liquid to form a hollow compressed powder material for extrusion; (c) compressing the hollow powder material taken out from the jig; The compressed powder material was coated in the annular cylindrical container by tightly accommodating and sealing the product in an annular cylindrical container having approximately the same shape, and then evacuation under heating conditions. (d) loading the hollow billet into a container of a predetermined indirect mandrel extrusion device, inserting and positioning a mandrel into the hollow part of the hollow billet; and the borrow billet so that substantially no phase displacement is caused,
The present invention is configured to include the step of forming a hollow extrudate having a predetermined shape in which the annular cylindrical container serves as a skin portion by indirect mandrel extrusion through a predetermined die.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

First, any general metal powder can be used as the powder material constituting the hollow extrusion powder material compact formed according to the present invention, but in the present invention, In particular, it can be advantageously applied to powder compacting operations of aluminum or its alloy powder. In addition to the above-mentioned metal powder, the powder material to be subjected to such molding may be a mixed powder material in which such metal powder is mixed with a ceramic material. The material is, for example, in the form of powder, long fibers, short fibers, whiskers, etc., and is generally mixed into the metal powder at a rate of 50% or less, especially about 10 to 30% by volume. It will be. In addition, such ceramic materials generally have 0% in powder form.
．． In the particle size of about 1 μrn-100 μm, and in the case of long fibers, the thickness is about 0.1 μm-100 μm, and in the case of short fibers, the thickness is 0.1 μm-t.
o.

μm, length: about 1m to 50mm,
And for whiskers, the thickness: 0.1 μm ~ 1
0/jm and length lpm-100 μm, respectively.

Then, in order to obtain a bundle-like compressed material (such powdered material (A material is then used for hollow extrusion) For example, as shown in No. 11-1, the compression dynamic forming jig has a core bar 2 in the center, an upper lid 4 and a bottom plate 6 on the upper and lower sides, and a cylindrical rubber container on the upper M4 and the bottom plate 6. Both ends of the metal core 8 are tightly pressed and attached by hands 10 and 10, respectively, so that a donut-shaped powder material filling space extending in the axial direction of the core metal 2 is formed.

In this jig, the core metal 2 is a member that determines the inner diameter dimension of the obtained compressed powder material, and its material is generally carbon steel, and after the powder material is compressed, it is extruded into a hollow shape. In order to make it easier to extract the compressed powder material, the core metal 2 has a taper of about 1/100 that tapers toward the top cover 4. The upper lid 4 and the bottom plate 6 are a part (A) that fixes the core metal 2 and the rubber container 8, and the material thereof is usually carbon steel and is connected to the core metal 2 with screws. ing.

Further, the rubber container 8 is a container filled with a predetermined powder material f412, and both ends thereof are fitted and fixed to the upper ri 4 and the bottom plate 6 as described above.
The circumferential portion is usually reinforced with fibers such as canvas. In addition, this rubber container 8
The wall thickness will be determined appropriately, but is generally about I
Q+u is commonly used, and the inner diameter and length are determined in consideration of the amount of shrinkage after compression processing (CIP), which will be described later.

Furthermore, the band 10 in such a jig is attached to the rubber container 8
is brought into close contact with the upper M4 and the bottom plate 6, and subjected to compression processing (CI
P) It acts to prevent water, which is a pressure medium, from seeping into the powdered material 12 inside, and is located outside the rubber container 8 between the top cover 4 and the bottom plate 6. , a guide pipe 14.14 having a half-split structure is provided to surround the rubber container 8, thereby performing compression processing (
This prevents the top cover 4 and bottom plate 6 from deforming during CIP.

The material of this guide pipe 14 is usually carbon steel, and the hydraulic pressure applied during compression processing (CI P) is
It is made to act on the rubber container 8 through the gaps between the guide pipes 14, 14, holes provided therein, etc., so that the rubber container 8 receives a compressive force in the radial direction, and the inside of the rubber container 8 receives a compressive force in the radial direction. Powdered material 1 filled in
2 is compressed.

Further, the filling of the powder material 12 into the hollow compression dynamic forming jig is carried out by putting a predetermined powder material 12 into the rubber container 8 with the upper M4 open. However, in this case, it is desirable to apply vibration using a suitable vibrating filling machine or the like, which can improve the packing density and can expect uniform filling.

Then, it is poured seven times in this way, and the prescribed powder I is placed inside.
The jig for forming a hollow compressed object filled with the material A 12 is housed in a pressurized container that can be pressurized with a high-pressure liquid, and is compressed by the action of a predetermined high-pressure liquid to achieve the purpose. A compressed bundle of material (hollow extrusion tube) is formed, and the operation is usually performed using a cold isostatic pressure step (Cold l5ostat step).
IC Processing (CIP).

FIG. 2 shows a schematic diagram of such a CIP process, in which a hollow compression dynamic forming jig filled with the above-mentioned predetermined powder material 12 is placed under high pressure having an upper lid 16 and a lower lid 18. is charged into the cylinder 20 and the water is transferred to the pressure medium 2
2, high pressure is applied to the charging jig. Note that this pressurizing pressure will be determined appropriately depending on the 120 types of powder materials and the required compaction density, but in the case of aluminum alloy powder, in order to obtain a compaction density of 65 to 70%, the pressurizing pressure should be 15kll. /
mm" or more is required. Also, this pressurization holding time is 5"
About a second is sufficient, but such a rapid increase in pressure to the target pressure will cause a difference in the compressed density of the powdered material 12 within the jig, so such a rapid increase in pressure should be avoided. desirable.

Further, the hollow compressed powder material obtained by such compression operation is taken out from the jig taken out from the compression device (high-pressure cylinder 20) by removing the top cover 4, etc., and then it is roughly removed. It will be tightly housed and sealed in an annular container of the same shape, an example of which is shown in FIG.

That is, in FIG. 3, the hollow compressed powder material 24 taken out from the jig has an inner cylinder 26, an outer cylinder 28,
The parts constituting the container are tightly housed and packed together in a toroidal (doughnut-shaped) cylindrical container composed of a bottom plate 30 and an upper lid 32, and each part is designed to prevent leakage due to vacuum evacuation, which will be described later. It will be completely welded and sealed.

Note that the hole 34 provided in the upper M32 is an exhaust hole for evacuation, and a vacuum exhaust pipe 36 is attached to this exhaust hole 34 as shown in FIG.

Further, as the material of the inner tube 26 and outer tube 28 of the cylindrical container accommodating the compressed powder material 24, a metal material with good extrudability is suitably used.
When 12 is a powder of aluminum or its alloy, or a mixed powder material of aluminum and a ceramic material,
It is desirable to select an aluminum material with good extrudability, such as A6063 or A1050. In addition, those inner cylinders 26,
The thickness 17 of the cylinder wall of the outer cylinder 28 is generally about 2 to 51 mm, and the length in the axial direction is the same as that of the compressed powder material 2.
The length is about 10 to 30 dragons longer than the length of 4.

Moreover, even if the bottom plate 30 and the upper lid 32 cover both ends of the inner cylinder 26 and the outer cylinder 28, the inner cylinder 26 and the outer cylinder 28
A material similar to that used is used, and the above A6063, A1
A material such as aluminum material with good extrudability such as 050 is selected. In addition, their shape is a perfect circular disk shape, and their wall thickness is generally 1 to 5 mm.
The outer diameter and inner diameter are approximately the same as that of the outer cylinder 28 and the inner cylinder 2.
6 will be selected so that the clearance between them is about 0.5 Cao Feng or less.

Furthermore, as shown in FIG. 4, a vacuum exhaust pipe 36 is attached to the exhaust hole 34 of the upper lid 32 of the container in which the predetermined compressed powder material 24 is housed.
Then, the gas in the container containing the compressed powder material 24 is removed through the evacuated trachea 36 by an evacuation device (not shown). The vacuum exhaust pipe 36 is made of a material that is easy to process, such as aluminum material such as A1050, and is made of a material that is easy to process, such as aluminum material such as A1050, and is made of a material that is easy to work with, so that there will be no leakage even if it is crimped and tightened after the vacuum exhaust operation. 1 yen of meat is 1/10 of the outer diameter
This is said to be the above.

Further, when evacuation is performed through the evacuation pipe 36 in this manner, the container containing the compressed powder material 24 needs to be heated. by this,
Volatile substances such as gases and water present in the compacted powdered material in said container are vaporized, effectively expelled, and removed outside the container, thereby This prevents the presence of gas, volatile liquids, etc., and thereby prevents troubles in the subsequent indirect mandrel extrusion process as much as possible. In addition, the heating temperature of the container at this time should be appropriately determined at a temperature not lower than the temperature of such heat history, depending on the degree of heat history that the compressed powder material 24 receives after the extrusion process. For example, in the case of heat treatment after extrusion, the heat treatment (quenching) temperature or higher temperature is adopted, and if the extrudate is not heat treated, the extrusion temperature or higher temperature is adopted as appropriate. This is what happens. Then, by evacuation under this heated state, a hollow billet 38 for extrusion is formed in the form of a circular cylindrical container (26° 28.30.32) coated with the compressed powder material 24. It will become.

Next, the hollow billet 38 for extrusion in which the powdered powder compressed material 24 obtained in this manner is sealed is preheated at 300 to 500° C. for about 1 to 5 hours for extrusion processing. The heating temperature of this billet 38 is such that -a is the preheating temperature before extrusion of the base material.
8 is loaded into a billet loading hole 42 of a container 40 of a predetermined indirect mandrel device, as shown in FIG. 5, for example. Moreover, in this billet loading hole 42, a die 44 that gives the desired hollow H extrusion shape is installed.
It is preheated to the same temperature as the billet 38 and set in advance.

Then, the loaded hollow billet 38 is inserted into the mandrel 48 that passes through the press plate 46 and reaches the die 44 position, and under such a condition, the hollow billet 38 is moved by the stem 50 to the press plate. 46
Extrusion is started by applying pressure through the . During this pressure extrusion, the container 40 is
It is moved at the same speed as the stem 50 in the extrusion direction indicated by the arrow by a separately driven movement mechanism, and thereby the inner surface of the billet loading hole 42 of the container 40 and the outer surface of the hollow billet 38 (specifically, the outer cylinder 28) Indirect mandrel extrusion is carried out in such a way that no relative displacements are induced during the process.

Therefore, in the indirect mandrel extrusion operation of the hollow billet 38 for extrusion, which is made by housing such a compressed powder material 24 in an annular cylindrical container (26, 28, 30, 32), it is necessary to No frictional force acts between the die 44 and the inner surface of the loading hole 42, and a dead metal portion formed at the abutting portion between the die 44 and the front end of the borrow billet 38 pressed by the die 44 becomes minute. As a result, the outer cylinder 28, upper lid 32, etc. that constitute the annular cylindrical container,
Compressed powder material 2 subjected to deformation action by extrusion pressure
4, and these constituent materials remain on the entire surface of the extruded product such as the hollow material 52 that is extruded through the die 44 as the skin 54, and thus the skin 54
This makes it possible to effectively obtain the hollow material 52 without any entrainment. Note that the skin 5 covering the surface of the hollow material 52
4 is made by suitable machining, such as surface cutting.
H can be simply removed, thereby making it possible to obtain the desired seamless, hollow, elongated tube.

Further, according to the manufacturing method of seamless hollow material as described above, a hollow compressed powder material for extrusion to which the indirect mandrel extrusion method is applied can be effectively formed by the above-mentioned 012 method, and It has the excellent advantage that the required compressed density is uniform and the compressed powder material 24 is difficult to break.Furthermore, since no lubricant is required during compression, the lubricant removal step is unnecessary. It is no longer necessary to consider the deterioration of the quality of the compressed powder material 24 and, ultimately, the final product, the hollow material 52, caused by such a lubricant.

Furthermore, by indirect mandrel extrusion of the thus obtained extrusion borrow billet 38 having good properties, it is possible to directly produce a seamless long hollow material with good quality. Since the container, lid, etc. of the hollow billet 38 are made of a material with good workability, wear and damage to the extrusion die 44 and cracking of the obtained hollow material 52 can be well prevented, and as a result, metal powder It became possible to obtain a seamless hollow material of good quality from a mixed powder material mixed with a ceramic material.

Since there is no die wear or cracking of the extruded material (52), it is possible to increase the extrusion speed, thereby significantly improving productivity. Since it is possible to extrude hollow materials such as pipes, it is even easier to manufacture hollow materials than the manufacturing process of hollow materials, which uses a solid billet, extrudes bar materials from it, and then cuts and drills holes in such bar materials. ,
This made it possible to significantly reduce costs.

It should be noted that the present invention is not to be construed as being limited only to the specific examples illustrated above, and various modifications and changes can 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 the present invention is subject to modifications, improvements, etc., and includes such embodiments.

For example, in the jig for forming a hollow compacted object illustrated in FIG. 1, as long as it is compressible and has an annular powder material filling space capable of forming a hollow compacted object, Jigs having various structures other than those illustrated may be used, and the compressed powder material 14 for forming the hollow fins 38 as illustrated in FIGS. 3 and 4 may be used.
4, the inner cylinder 26 and the outer cylinder 28 are integrally joined at the bottom plate 30, and are a double cylinder with a bottomed cylindrical shape. It is possible to use a combination of upper 132 for the body.

Furthermore, even in the indirect mandrel extrusion method, instead of moving the container 40 and stem 50 at a constant speed as in the previous example, the container 40 and stem 50 are fixed, and the die 44 is moved toward the stem 50. It is also possible to adopt a pressing method, in other words, a method in which the die 44 is moved to the left in FIG.

In addition, the hollow material obtained according to the method of the present invention can be used as it is (with the skin 54 still attached), and...
As mentioned above, it can be used even with the skin removed, and furthermore, the extruded hollow material can be subjected to appropriate heat treatment, sintering, etc. as necessary. be.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view showing an example of a jig for forming a hollow compressed object used in the present invention, and FIG. 2 is an explanatory cross-sectional view showing an example of a compression method using hydraulic pressure of the jig for forming a hollow compressed object. FIG. 3 is an exploded view of a hollow container for storing compressed powder material, FIG. 4 is a cross-sectional explanatory view showing the assembled and evacuated state, and FIG. The figure is a cross-sectional explanatory view showing one form of indirect mandrel extrusion according to the present invention. 2: Core metal 4 = Top lid 6: Bottom plate 8: Rubber container 11tn powder material 14 Guide vibe 16: Top lid 1
8: Lower lid 20: High pressure cylinder 22: Pressure medium 24: Compressed powder material 26: Inner cylinder 28: Outer cylinder 3'o: Bottom plate 32: Upper lid 36: Vacuum exhaust pipe 38: Hollow billet 40: Container 42: Billet loading Hole 44: Die 48: Mandrel 50: Stem 52: Hollow material 54; Skin Applicant: Sumitomo Light Metal Industries, Ltd.

Claims (1)

[Claims] A step of filling a compressible hollow compression motion forming jig with a predetermined metal powder or a ceramic material mixed therein; A compression dynamic forming jig is housed in a pressurized container that can be pressurized with high-pressure liquid, and by applying a predetermined high-pressure liquid, the jig is compressed to form a hollow powder material for extrusion. The process of forming a compressed material and the step of tightly accommodating the hollow powdery material compressed material taken out from the jig in an annular cylindrical container of approximately the same shape and sealing it, then vacuum evacuation under heating conditions. forming a hollow billet for extrusion in which the compressed powder material is coated in the annular cylindrical container; loading the hollow billet into a container of a predetermined indirect mandrel extrusion device; and , by inserting and positioning a mandrel in the hollow part of the hollow billet, and by indirectly extruding the mandrel through a predetermined die without substantially causing relative displacement between the container and the hollow billet. 1. A method for producing a seamless hollow material made of a powder material, comprising the step of: forming a hollow extrudate of a predetermined shape in which an annular cylindrical container serves as a skin portion.