DE2243819A1 - METHOD OF CONNECTING WIRES FROM COMPOSITE MATERIAL - Google Patents

Description

PATENT Attorneys ^ g

DiPWNOt RICHARD SCHLEE ^ -SS ^ frÄssJJ

DiPL-iNG. HELMUT MISSLING phone: (ρβιυ τιοιβ

DR.-ING. JOACHIM BOECKER S / B 11.278

Allmänna Svenska Elektriska Aktiebolaget _? Västeras / Sweden

Method for connecting wires made of composite material

The invention relates to a method of joining of wires made of composite material with a core made of aluminum and a sheath made of copper, with two wire ends joined together are, preferably by cold butt welding, so that the cores of the two wire ends pass over homogeneously and the connection point, after removing a possibly formed there Bead, with a facing metal in IOrm of copper or other metallic material with good plastic working properties and good electrical contact properties, e.g. Silver or gold, is occupied.

When pulling wire on a draw bench for. Manufacture of wire with smaller diameters, it is common that one successively connecting pieces of the thicker wire to make the drawing process continuous and the finer wire in unlimited. Stomach. It is special

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desirable this method in the manufacture of composite wire with a core made of aluminum and a sheath made of To be able to use copper, not least because it It is advisable to use the first generation of hydrostatic wire from this material with a diameter of 5 to 10 mm To manufacture extrusion presses. This gives you material in limited lengths that can be used for most purposes finer dimensions are drawn

It has proven very difficult to clad wire out of copper To connect em aluminum in such a way that the wire can be drawn and the connection point after deji Draw has satisfactory electrical, mechanical and physical properties. Connecting with rtilfe welding methods in which the wire is heated has led to such changes at the joint, that the wire breaks when pulled. A major contributor to this The reason for this is that hard and brittle alloys easily form between the components when the wire is heated. Man has therefore tried to avoid such methods in the case of dens the wire is heated to a high temperature.

It is known to carry wire made of copper-clad aluminum Cold butt welding (cold head welding) of aluminum cores at the wire ends that are to be connected

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add, and replace the copper that is removed from the connection point after aas butt welding with new copper. This is done by attaching a copper sleeve over the exposed aluminum surface and the adjoining surfaces, the copper jacket and joining the sleeve with the illuminium core and thine . copper jacket by Sprengschwei.Sen the explosive is doing as an outer sleeve U: .n placed aie copper sleeve a slightly greater material thickness than the copper jacket of the wire B, however, has shown that this method also has Geesthacht hurry can _namely.?. certain cases problems occur here, connection points with a reproducibly good connection between the placed at the junction of the copper and the underlying aluminum obtained au. This may result in that the launched copper is peeled off when pulling or peeling. 13s should be mentioned ₅ that an electrolytic Applying copper to the ver Binding site results in significantly worse results than the blasting method described, since the connection with the aluminum. becomes completely unsatisfactory.

The invention is based on the object of a method to propose the type mentioned above, with which a better connection between the applied material and the core is achieved than this with the known methods of Pa

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This object is achieved according to the invention in that the covering metal is applied by means of cathode sputtering will. In this case, after the cores of the wire ends have been joined together, no heating is necessary for the formation of brittle alloy layers. The atomization is also carried out below the harmful temperature mentioned. The better bond is the large energy content of the copper atoms on impact with the aluminum surface, and the property that the copper layer is effectively anchored to the substrate at each point. A mechanical one This means that the load on the copper layer is evenly distributed over the entire connection point. That leads to the fact that the tendency of the copper layer to be peeled off or peeled off during drawing is significantly reduced. One Another important property of the cathodic sputtering method is that it is possible to apply any desired thickness of the coating Produce copper layer. So, contrary to what is the case with the blasting method, you have the Possibility of applying very thin copper layers if necessary. Such a thin layer of copper that is firmly attached to the Underlay is anchored, follows a lOrm change of Underlay lighter without damage than a thicker layer.

In addition to cold butt welding, the wire ends can also be welded using friction welding or electron beam welding

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be joined together. ■

As I said, besides copper, other facing metals can also be used. The condition is that they are plastically deformable so that they can follow the change in shape of the wire without tearing, and also that they have good contact properties and thus a low contact resistance to the connecting element. This assumes that they are not covered with insulating oxide layers in air and that they have sufficient electrical conductivity in themselves. In addition to copper, which is preferred, silver, gold, tin and several tin alloys with more than 50 percent by weight tin can be used.

According to an advantageous embodiment of the invention the copper sheath is removed from the wire ends to be connected before the cores of the wire ends in question are joined together will. Bs has proven to be particularly useful for achieving a good quality connection part that the Copper sheath is tapered on each wire end, e.g. by cutting or grinding towards the ends, before the facing metal is applied. ,.

As can be seen from the above, the covering metal can be applied in the form of a thin layer. The shift can

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much thinner leg than the sheath of the wire and with Advantageously, it can be applied in a block of 0.1 to 100 / rev. In many cases a thickness of 0.1 to 10 / U is preferred. At least when using a facing metal cover that is much thinner than the thickness of the jacket, it is advisable to compress the wire ends when joining, so that the diameter of the core at the junction is at least as large as the original diameter of the wire, as well as that possibly over the original Any parts protruding from the wire diameter must be removed before the covering is applied.

The invention is illustrated below through a description of an exemplary embodiment with reference to the accompanying drawings described. Show it;

Fig. 1 in longitudinal section two wire ends that are connected should be

Pig. 2 the same wire ends after they have been pretreated for joining,

Pig. 3 the pretreated wire ends in a joining tool before joining,

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Pig. 4 the ones removed from the dear tool, with one another connected wire ends,

5 post-treatment of the same wire ends for the purpose of application of the covering metals,

ig. 6 coated the same wire ends with copper and

. 7 a visual sketch of a cathode sputtering device, with which the application can be carried out.

The wire ends to be connected are in Ji ¹ Ig. 1 shown. Each wire has a core la or 1b made of aluminum and a sheath 2a or 2b made of copper. In the case of the I ¹ SiIl described as an example, the diameter of the wire is 8 mm and the layer thickness of the jacket is 0.3 mm. Before joining, the copper corn at the end of each wire end is removed as shown in 3? Ig. 2, so that an exposed aluminum surface 3a or 5b is produced. Furthermore, the copper corn is beveled in the area 4a or 4b on the exposed aluminum surface, so that the thickness of the hanteis is reduced. exposed Alumiiiiuiüflache gradually almirwit. ·

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Pie both wire ends are then as shown in FIG. 3 with jaws 5a and 5b detected, on which calibration gripping surfaces 6a and 6b are located. The wire ends are centered · the jaws with a Bridge, which considerably exceeds the yield point for aluminum, compressed. The jaws are provided with cavities 7a and 7b to accommodate burrs and with cutting edges that form the burr cut off. When pressed, the cores 1a and 1b flow together, so that they merge homogeneously into one another, which means that the The core at the junction is just as strong as the rest of the core. At the same time, how out Fig. 4 shows the cores of the wire ends compressed so that the connection point 8 of the cores has a larger diameter than the wire itself. The connection point is then smoothed with e.g. gets a uniform surface, as can be seen from FIG. The wire is now finished to apply the covering metal. The covering metal, in the present case consisting of copper, is applied to the connection point 8 by cathode sputtering. where the aluminum comes to the surface of the wire and is applied to the adjacent parts of the copper jacket 2a or 2b. The covering, denoted by 9 in FIG. 6, is very thin; its thickness is only a few / u. The thickness is therefore greatly increased in the drawing. The increase in thickness at the junction is so insignificant that it prevents the pulling of the wire in one

Drawing machine not affected.

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When applying the B3.agmetal, the in fig «, 7 sehematiseh sputtering equipment shown were used. she includes a chamber 10 containing low pressure argon. In the chamber are an anticathode 11 and a substrate holder 12 arranged, both have connecting conductors 13 and 14 for electricity. The cathode 11 consists of the material that is to be atomized, in this case copper, as well as a holder for this material. On the substrate holder

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the / coating object 15 is arranged, & »h _e in this case the in Jig. 5 shown © wire connection point. The wire is wound on both sides of the connection point on reels 16 and 17, which are rotatable with motors, not shown, in such a way that the wire in the chamber 10 can rotate about its axis. The wire runs through vacuum-tight passages 18 and 19 through the walls of the chamber. A displaceable screen 20 is also arranged in the chamber, which screen can be arranged both in the area between the cathode and the substrate holder and outside this area. This is shown in the drawing in that the screen can be rotated about a vertical shaft 21 in a vacuum-tight bushing 22. .

The sputtering arrangement works in the way that the argon gas in the chamber is ionized,

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when a voltage is applied to the cathode 11 and the substrate holder 12 is created. The positive ions that are formed are from attracted to the negatively charged cathode. At the same time, atoms are knocked out of the cathode, in this case copper atoms. The copper atoms move across the chamber and hit the object 15, i.e. the wire connection atelle, which against the substrate holder 12 is supported. When hitting the At the connection point, the copper atoms form a layer of copper on the connection point. By getting the wire at least rotated once, you get around the whole junction around a topping.

During the above-described process, the screen 20 is not used. It is in a position outside the area between the cathode and the substrate holder. The umbrella is at sogti. Used ion etching, in which the sputtering is carried out in reverse. During ion etching, the poles are opposite, so that the substrate holder 12 is negative and the part 11 is positive. The ions produced in the chamber bombard then instead the object 15 _t being cut off from its surface impurities, such as oxides. The screen 20, which in this mode of operation is shifted into a position between part 11 and substrate holder, catches the impurities.

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When occupying the connection point according to the present invention, it is expedient before the actual cathode sputtering process perform an ion etch to remove the oxide from the aluminum at the junction. To After ion etching, the screen is removed from the area between the cathode 11 and the substrate holder and the poles are removed vice versa, so that the cathode is charged negatively and the substrate holder is charged positively. This will occupy the junction started with copper, which is free of impurities thanks to the previous ion etching.

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Claims (5)

Patent claims: 1y Method of connecting wires made of composite material with a core made of aluminum and a sheath made of copper, whereby two wire ends are joined, preferably by cold butt welding, so that the cores of the two wire ends merge homogeneously into one another and the connection point after removal a possibly formed bead there, with a covering metal in the form of copper or other metallic material with good plastic working properties and good electrical properties Contact properties, e.g. silver or gold, is proven by gekenuKeicliTEfc that the covering metal (9) is sputtered using cathode is applied. 2. The method according to claim 1, characterized in that the Copper sheath (2a, 2b) is removed from the wire ends to be connected before the cores (1a, 1b) are joined together. 3. The method according to claim 1 or 2, characterized in that the copper jacket (2a, 2b) at each end of the wire e.g. cutting machining or grinding is tapered towards the ends before the facing metal (9) is applied. 4. The method according to any one of claims 1 to 3, characterized in that that the wire ends are compressed when joining, so that the diameter of the core at the connection point - 13 309812/0213 is at least as large as the original diameter of the wire, as well as that possibly over the original .Wire diameter protruding parts are removed before the covering metal (9) is applied. 5. The method according to any one of claims 1 "to 4, characterized ge kenn-. shows that the lining metal (9) with a thickness of 0.1 "to 100 / U, preferably 0.1 Ms 10 / U is applied. 3098 12/02 13