JPH02263938A - Manufacturing method and device for dispersion-strengthened copper molded products - Google Patents

Abstract

PURPOSE: To economically produce a dispersion strengthened copper formed product without developing segregation by forming boride in overheated molten copper, stably dispersing therein, weighting and charging this molten copper in a press-base die and forming through a stamper.

CONSTITUTION: Into the overheated molten copper at the max. 300°C, the boron together with the boride forming element till exceeding 1.5wt.% to the stoichiometrical content to form the boride, are added. As the boride forming element, one or more kinds among IVA, VA and VIA group elements, aluminum, etc., are used, e.g. Al, Ti, Zr, Hf, V, Nb, Cr, etc., is suitable. By adding these elements, the dispersed quality molten metal holding 1-35vol% boride in copper matrix, is obtd. This molten metal is weighed and charged into the press-base die 3 or conditioned in this die and just after this operation, this molten metal is cast-formed through a stamper 4. At this time, it is desirable to apply the press-pressure at 5-70 bar. Thereafter, the formed product is taken out from the die 3 with an ejecting device 6. By this method, the dispersion-strengthened copper formed product having uniformly dispersed boride, is obtd.

COPYRIGHT: (C)1990,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing dispersion-strengthened shell molded parts and an apparatus for carrying out the method.

BACKGROUND OF THE INVENTION Dongdian dispersion-strengthened materials are used industrially in applications requiring a combination of properties of high heat resistance and high electrical and thermal conductivity, such as in the electronics and welding and automotive engine industries. This is extremely important.

Nevertheless, these materials have not really been of any particular value to date (1) because, as soils, the powder metallurgical processes usually employed for these materials are not always economically viable; The point is that it's not enough.

For example, a reinforced mold material is used for the oxide chamber 11 using the internal oxidation method:
(The semi-finished product obtained by the manufacturing method of Cu-1/!□0.
Because of their low ductility, they can only be made into molded parts by post-processing in a strain-free state. However, with this processing method, a product close to the final shape is produced with a large amount of material t.
The original advantages of the non-metallurgical process are lost.

To date, no economical manufacturing methods, such as casting, are known for dispersion-strengthened copper materials, which are suitable for minute W1 qualities, such as AI! 03 and BeO gravitational segregation (Schwer
This is due to the fact that it cannot be homogeneously suspended in molten copper without oxidation. Attempts to limit gravitational segregation in the f8 melting barrel by the action of ultrasonic waves have not yet yielded concrete results.

The present invention provides an economical method for producing reinforced copper molded parts based on a melting process;
And to provide equipment for carrying out the method! ! i! Based on the subject.

(Means for Solving the Problems) These problems are solved by the method of claim 1 and the device of claim 13.

The present invention satisfactorily overcomes the problem of zero-gravity segregation, resulting in an economical process for producing molded parts or parts close to final shape based on a melt process with low material loss. The manufactured parts exhibit even better material properties.

The inventors have determined that if a dispersed phase that exceeds the precipitation reaction is obtained at that location in the melt, a uniform distribution of the fine fraction nk'ff in the molten liquid metal matrix can be achieved very easily. I left. However, the prerequisite for this is that the formation of dispersoid nuclei takes place uniformly,
and the critical radius of the nucleus is kept small 0
The present inventors found that the above material system corresponds to this, and in that case, Cu-^1-B, Cu-T! -B, Cu-Z
r-B, Cu-1ff-B, Cu-V-B.

In the study of Cu-Nb-8 and Cu-CrB t8 melts, the above prerequisites are the system Cu-AIDI, Cu-T
i1lz, Cu-Zr11g, Cu-HfBz+Cu
-VBg, Cu-NbB1 and Cu-CrBz were shown to be particularly highly filled. Due to their extremely small solubility products in the molten liquid shell and their extremely high melting temperatures, the intermediate compounds AIBx, TiBt, zr[li, l1fBi, She,
, sbn.

and CrBg always form homogeneous nuclei from molten copper and precipitate at a small critical radius, with molecules of various dispersoid shapes, e.g.
fi may be generated.

Formation of a stable dispersoid dispersion is confirmed over a wide saturation range of the above additive elements. Due to the low melting temperature and relatively low selected supersaturation, the tendency for zero gravity segregation can be delayed for long periods of time.
In the case of the element recited in claim 4, the difference in the density of the produced boride with respect to copper is small, so that the density difference r (++r
n, there is no essential difference), there is almost no tendency for gravitational segregation.

This is because some amount of boride floats in the melt.

Since the dispersoids in the melt do not agglomerate and are unlikely to become coarse, in principle these melts are post-processed by casting into molded parts. However, this cannot be done by conventional casting methods because of the low fluidity of the melt - which is associated with high viscosity due to significant supersaturation and low superheating.

According to the invention, this is solved by shaping the melt between the stamper and the press mold, whereby a good degree of mold filling is achieved. The necessary equipment can be easily made, and the molten liquid can be simultaneously solidified by a stamper using a mold. There are few solidified parts (
Both already have a form close to the final shape and can be finished in any way or used as initial material for semi-finished products.

The melt Ω processing method according to the present invention is easy to operate and can be automated as is;
The equipment described in section 2.1 is suitable.

To summarize the advantages of the melt composition used and the processing of the melt into cast parts, the advantages of high productivity, high structural quality, form accuracy and surface quality in a process with moderate material rtt efficiency and flexibility are summarized. be.

Steel casting parts of high quality value are obtained if materials such as hot-worked steel and materials based on molybdenum, tungsten or consisting of hard alloys are used for the press mold and the stamper.

A pressing pressure of 5 to 70 bar ensures solidification of the copper matrix, especially in finely divided form. A slight stoichiometric excess of the boride-forming elements provides additional age hardening effect.

In many applications, it is advisable to meter the melt or to prefeed the melt material in the form of a powder compact to the press mold.

This allows particularly small casting parts to be produced,
Alternatively, an additional melting device can be omitted, and melting, shaping and solidification can take place in one mold block.

According to the invention, various molded parts, for example those according to claim 11, can be produced economically, and instead of copper removal, gold or silver can also be charged.

In the following, the invention will be explained in more detail with reference to the drawings.

FIG. 1 shows a first embodiment for explaining the device and method of the invention by means of their individual processing steps.

FIG. 2 shows an advantageous variant of the device described in accordance with FIG. 1 for automating the method according to the invention.

FIG. 3 shows three different configurations of the loading device shown in FIG.

FIG. 4 shows a second embodiment of the apparatus and method of the invention, in which the melt is obtained in a press mold.

Figure 58 shows the tube! ! Figure 5B shows a tube piece manufactured according to Figure 5A;

In all the methods of the invention and the apparatus for implementing them, which will be explained below with reference to FIGS.
Sprayed copper supersaturated with Group A boride-forming elements and/or aluminum is used. For example, the composition of the molten system is C□In□.

Cu-Ti[1g, Cu-ZrBz+Cu-11rBz
, Cu-V[lt, Cu-NbBg or Cu-Cr
One or more systems of R1 are used. boron,
and the supersaturation of the melt f'l with boride-forming elements or aluminum up to 300
A homogeneous boride dispersion is suddenly formed in the melt heated to 'C.

Uniform nucleation and a variety of shapes, including small rod-like, fibrous or prismatic dispersoids produced at a very small critical radius, 1iIf,'! Stable and homogeneous boride dispersions of T can be produced over a wide range of supersaturation. For example, the above types of chemistry! ] The supersaturation by the additive of monotheoretical ■ is
A boride dispersion of 1 to 35% by volume retained in the copper matrix is chosen to produce.

Furthermore, in order to further increase the strength of the molded part, it is preferred to process with a slight excess of the boride-forming element over the chemical composition required for boride formation;
This excess can amount to up to 1.5% by weight.

Preferably the boride-forming elements and/or aluminum mentioned above are present in the melt in an amount of 2 to 17% by volume, especially 2 to 14% by volume.
% by volume of boride is charged for production.

The sprayed copper containing the boride-forming elements is further melted, preferably with the melt heated to 50 to 150'C.

In addition to copper-containing melts, metallic silver and gold-containing ones can also be used, in particular the behavior of gold and silver in these melts with respect to titanium and zirconium borides. A surprising coincidence can be seen.

In the embodiment of the present invention shown in FIG. 1, FIG. 1a schematically depicts the melting process for obtaining the above-mentioned melt. Here) 8 molten material t't is placed in a crucible surrounded by an induction coil with a sleeve brick 2, the lower opening of the crucible being closed with a stopper rod l. In the melting process in the above temperature range, boron reacts with boron and boron-forming elements in the melt supersaturated with boron-forming elements to form an intermediate compound, resulting in the rapid and drastic formation of dispersoids in one volume of the melt. occurs.

In the casting process shown in FIG. 1h, the stopper rod l is lifted upwards until the stopper rod is pushed down into the outlet.
The press mold, which flows into a mold provided as a press mold 3 and placed below the sleeve brick, is formed at its bottom, in this embodiment in the form of a protruding stamper. A vertically movable ejector device 6 is provided, which closes the bottom of the press mold 3 during casting. In this form, the press mold is formed hollow.

However, in addition to this, different cavity shapes can also be considered, depending on the molded part to be produced.

In the melt pressing process shown at 114 in FIG. 1c,
A stamper 4 descends from above into the press mold 3 filled with the melt and applies a pressure of approximately 5 to 70 bar to it, whereby the melt containing the dispersoids is molded under the press pressure into the molded part. It becomes 5. The molded part 5 is solidified by the usual means in melting technology, for example with the aid of rapid solidification by water cooling, and after drawing out the stamper 4 it is
In the processing steps shown in the figure, the top 1 of the protruding device T1G. The movement causes it to be ejected from the press matrix 3.

The materials used for the stamper and the press mold are hot-working steels, in particular materials based on molybdenum or tungsten or hard metals produced by powder metallurgy.

In order to automate the manufacturing process shown in Figure 1,
Rotate multiple molds or master molds on a rotating table (Karssel l)
This can be done by filling the molds with melt stepwise, especially under a fixed feeding device, and then pressing them, especially under a similarly fixed, stamped arrangement. FIG. 2 schematically shows a corresponding turntable arrangement, which comprises a fixed charging device 8 arranged above the turntable and rotates on a rotating shaft 9. The mold block 10 is housed in the 9-turn table which is installed in a possible state. First, when the left mold block is pulled by the rotation of the turn table and is below the charging device 8, the charging device is placed in the mold block. 8 is filled with a precisely measured amount of melt 11. This corresponds, for example, to the device shown in FIG. 1 with a sleeve brick and a stopper rod.

As soon as the precisely metered amount of melt has been injected, the filled mold block 10 is guided by rotation of the corresponding turntable under the device with the stamper 4 which is also fixed. The stamper is then pushed into the melt 11 in the same way as in FIG. After pulling out the stamper 4, the molded part 5 is taken out. Fixed, turntable and stamper
As the ejecting device installed below the device with a length of 61M, an ejecting stamper 6 and an ejecting cam 7 disposed below the stamper are used. After ejecting the cast part, the now empty mold block 10 is again guided under the charging device and the production cycle is started anew. Therefore, by housing two or more mold blocks in the turntable,
Two operating steps can be performed simultaneously. If desired, two or more charging devices, stamper arrays, and ejecting devices can each be fixedly installed with respect to the rotary table at regular angular intervals.

As a charging device, for example, charging devices 8a, 8b, 8c shown in FIG. A simple solution is depicted: an induction coil surrounding the crucible with a stopper rod closing the melt; Generate temperature.

It has been found that, especially for producing small molded parts, it is better to melt just a predeterminable amount of melting material, as shown in tf& in FIGS. 3b and 30. To obtain the molten material, powders are prepared by separate nozzle extrusion of the molten melt or the copper-zirconium melt and the copper-boron melt, which are then combined and compacted. and make a compressed product of the required weight. According to FIG. 3b, a powder compact 13 of this type is melted in a crucible 2' surrounded by an induction coil 12, as in FIG. It reacts with the particles and becomes the boride of the target star. After melting, the melt containing homogeneous boride fraction 11 flows out of the opening of the crucible into a mold block 10 (FIG. 2) located below it.

In the case of a suspension melting process using a suspension melting coil 12' surrounding a suspension melt 13' obtained from a powder compact, as depicted in FIG. 3c, a suspension melt containing a corresponding homogeneous boride dispersion The liquid flows into the mold block after cutting off the coil current.

FIG. 4 shows a second embodiment of the invention, in which the melt is obtained directly in the mold block 10 or press master mold. This quickly molds parts by direct energization! ! ! make it possible to build A mold block 10 made of a material with low electrical conductivity is charged, as shown in the upper part of FIG. 4, with a powder compact that can be prepared according to the above description.

The protruding stamper 6 arranged movably in the lower part of the mold block 10 simultaneously acts as a positive current contact, and the current contact 14 installed at the longitudinal end of the press stamper 4 corresponds to the negative pole. ing. The compressed powder 13 is melted by directly applying current to the current contacts 6 and 14 and the stamper 4, and after the current is cut off, the cast part 5 is rapidly solidified by the pressure applied to the stamper 4 pushed into the melt. This can be removed with the aid of a protruding stamper 6. In this case, the stamper 4 is made of a material with good thermal conductivity, such as molybdenum or tungsten.
It is important that the In order to further improve the heat dissipation of the solidified melt, it should be cooled with water.

FIG. 5 schematically shows another embodiment of the form of the melt pressing apparatus, which is indicated in particular for the manufacture of tubes. Mold block lO
includes a cylindrical cutout for containing the melt;
To the bottom of this cutout, a movable projecting pin 6' extends through the bottom of the mold block 10, the end of which projects from the mold block being tensionable by means of the spring shown, and the melting of the block 10 The cutout for liquid is closed from below. Is the stamper melted? The round bar 4a which is pushed into the &ll, which has the inner diameter of the pipe piece to be produced, and the upper stamper part 4b, which is provided below the hollow fitting and the spring containing the spiral spring inside. It is equipped with a guide ``1'' for the round bar 4a.

When the stamper is lowered into the melt, the lower side of the round rod 4a protrudes and hits the bottle 6', whose diameter is approximately equal to the diameter of the round rod 4a, compressing the bottle 6' slightly downward by the action of its spring. . The spring of the stamper part 4b is also a round rod 4a.
The underside of the stamper part 4b, which has the same diameter as the flock cutout, rests on the upper surface of the rising melt, so that the melt flows between the stamper parts 4a and 4b and the mold block (the cutout). be trapped.

After the melt has solidified, the stamper moves upwards 71, and the ejector bottle 6', which is under tension due to its compressed spring, moves upwards and ejects the final tube piece 15 shown in FIG. 5R. The apparatus of FIG. 5 is suitable for the automatic production described in FIG. 2 and provides a fast, simple and unobjectionable tube piece.

In addition to the devices for melting and shaping described below, any other configurations are possible, as long as the supply of melt or melt material and shaping under press pressure is ensured.

[Brief explanation of drawings]

FIG. 1 shows a first embodiment for explaining the device and method of the invention by means of their individual processing steps. FIG. 2 shows an advantageous variant of the device described in accordance with FIG. 1 for automating the method according to the invention. FIG. 3 shows three different configurations of the charging device shown in FIG. FIG. 4 shows a second embodiment of the apparatus and method according to the invention, in which the melt is heated in a press mold (7). FIG. 5A shows a further embodiment of the apparatus according to the invention for producing tubes. , FIG. 5B shows the tube piece manufactured according to FIG. 5A. In each figure, the symbols represent the following: 1; plug rod 2.2' j crucible 3; io nibless master mold (mold block) 4; 4a, 4
b Nistambar S, tS: Molded parts 6.7.6' i Ejection device 8, 8a, 8b, 8c: Charging device amount Roll axis 11: Melt 12° 12': Induction coil 13: Powder compact 14: Electric 2-it contact Fig, 2 (4 other people) Fig, 1 Fig, 3 Fig, 4 Fig, 5A ≦ Fig, 5B

Claims (1)

[Scope of Claims] 1. Boron and one or more boride-forming elements of groups IVA, VA and VIA of the Periodic System of the Elements and/or aluminum, which rapidly Preparing molten copper that is supersaturated and heated to up to 300° C. to the point that a homogeneous, significantly stable boride dispersion is formed, and adding a predetermined amount of this boride-containing molten copper. A process for the production of dispersion-strengthened copper moldings based on the melting process, characterized in that they are prepared in a press mold or are metered into it and shaped with the aid of a stamper immediately after its preparation or charging. . 2. 1-35 in which molten copper is held in a copper matrix
Process according to claim 1, characterized in that it is supersaturated with stoichiometric amounts of additives boron and boride-forming elements to form a boride dispersion in % by volume. 3. Process according to claim 1, characterized in that the boride-forming elements are added with an excess of up to 1.5% by weight over the stoichiometric composition of the borides formed in the melt. 4. Any one of claims 1 to 3, characterized in that one or more elements among aluminum, titanium, zirconium, hafnium, vanadium, niobium and chromium are used in the melt as boride-forming elements. Method described in Crab. 5. Process according to any one of claims 1 to 4, characterized in that the molten copper is heated to 50-150°C. 6. boron and aluminum to form a 2-17% by volume retained boride dispersion in the melt;
6. The method according to claim 1, characterized in that one or more elements selected from titanium, zirconium, hafnium, vanadium, niobium and chromium are added. 7. Claims 1 to 6, characterized in that a press pressure of 5 to 70 bar is applied during casting of the dispersoid-containing melt.
The method described in any of the above. 8. For metering a predetermined amount of the boride-containing melt, a powder compact of a predetermined composition and corresponding mass is placed in an open crucible above the press mold;
8. A method as claimed in claim 1, characterized in that the melting takes place in a suspension melting coil from which the melt falls downward into the press mold after switching off the coil current. 9. Any one of claims 1 to 7, characterized in that a weighed powder compact of a predetermined composition is loaded into a press mold, melted by direct electric current, and then molded by the pressure of a stamper. Method described in Crab. 10. Preparing a powder compact by mixing nozzle-extruded copper-zirconium and/or copper-titanium alloys in the proportions necessary to supersaturate the copper-boron alloy and compressing the mixed powder. A method according to claims 8 and 9, characterized in that: 11. The method according to the invention produces the following final molded parts or at least corresponding structural parts close to the final shape: spot welded electrode caps, valve guides and valve seat rings for internal combustion engines, electrical contacts, closure parts for chemical devices, and , characterized in that it produces structural parts, elements for rocket drives and nozzle drives, ingot cases for strand casting, initial materials for the production of tubes, wires and profiles, drive parts such as synchronization rings, and screw blanks,
A method according to any one of claims 1 to 10. 12. The method according to any one of claims 1 to 11, characterized in that silver or gold is used in the melt 11 instead of copper. 13. A press mold (3; 10) containing the melt material into which the boride-containing melt can be metered or for preparing the boride-containing melt, and in which the melt is shaped. (4; 4a; 4b), in which the press die and the stamper are made of hot-worked steel or, in particular, of a powder metallurgically produced material based on molybdenum or tungsten, or of a hard Claims 1 to 12 characterized in that it is made of metal.
An apparatus for carrying out the method described in any of the above. 14. Two or more mold blocks (10), each with one press mold, are arranged on a rotary table, and a fixed charging device for charging a measured amount of melt into the mold blocks. (8a; 8b; 8c) one or more above the turntable and fixed ejection devices (6, 7) for ejecting the solidified molded part (5) from the mold block;
) one or more mold blocks (10) are arranged in position below the turntable, into which mold blocks (10) empty or filled with a measured amount of melt are continuously moved by the rotation of the turntable. In this case, one or more stampers (4) for molding the precisely charged amount of melt are placed above the moving mold block, in particular the ejecting devices (6,
14. The device according to claim 13, characterized in that it is installed in a position corresponding to point 7).