DE102016206005A1 - Process for the production of wires - Google Patents

Abstract

The present invention relates to a method of manufacturing a wire wound on a reel (11) having a plurality of windings and a wire accordingly made, the length of the wire being much larger than the diameter or a maximum dimension of a cross section of the wire across Wire longitudinal direction, wherein in the method at least two wire parts (1,2) are provided, which are connected to end faces of the wire parts which extend transversely, in particular perpendicular to the wire longitudinal axis, wherein the joining of the end faces by welding or soldering.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to a method of manufacturing a wire wound on a spool having a plurality of windings, and to a wire made accordingly.

STATE OF THE ART

Generative manufacturing processes, in which components are produced in layers by layer-wise deposition of material, enable effective and rapid production of components. In addition, they allow the production of components from materials that would otherwise not be available through other manufacturing processes. For these reasons, additive manufacturing processes are becoming increasingly popular in the industry.

In generative manufacturing processes, one can distinguish powder bed processes and processes with direct local supply of powder or wire to the deposition site. For some manufacturing processes in which the materials used are to be supplied directly locally, such as generative electron beam deposition welding, only wire can be used, since powder could be distributed uncontrollably in a corresponding vacuum chamber. In addition, there could be adverse effects from electrostatic charges in the electron beam welding process.

In addition, the supply of the material for layer-wise deposition in wire form is more advantageous because the wire has a substantially lower surface area than powder, based on the amount of material, and as a result fewer oxides can be incorporated into the melt during layer-wise melting. Furthermore, welding wires provide a continuous supply of material without negative inclusions, such as pores, so that the process stability is better than with the use of powder.

However, there are materials that are not available in wire form because of their brittleness or low elongation at break, since they are not accessible to the usual drawing process for the production of wires, so that either certain generative manufacturing processes such as electron beam welding can not be used and / or the disadvantages of powder use described above can not be eliminated.

In particular, it is a problem if wires can not be provided in a sufficient length, since the provision of a sufficiently long wire, which is usually wound on a spool, is a prerequisite for a reasonable implementation of the corresponding methods.

DISCLOSURE OF THE INVENTION

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a method of manufacturing a wire so that the wire is wound in a sufficient length on a spool. The corresponding method should be simple and effective feasible and a correspondingly be provided wire should be provided without affecting the material properties.

TECHNICAL SOLUTION

This object is achieved by a method having the features of claim 1 and a wire having the features of claim 10. Advantageous embodiments are the subject of the dependent claims.

The invention proposes, in the case of materials in which only relatively short wire parts can be provided, since they do not have sufficient deformability for pulling the wire, for example, at least two, preferably a plurality of wire parts at their end faces which extend transversely, in particular perpendicular to the wire longitudinal axis to connect with each other, wherein the joining of the end faces by welding or soldering takes place. This makes it possible to provide a correspondingly long wire, which can be wound according to its deformability on a suitable coil in order to be available for different applications. Winding on a spool can also be done with materials of limited ductility, ie elongation at break, taking into account that the deformation introduced into the wire during winding of the wire is smaller than the breaking elongation. Accordingly, care must be taken only that the minimum radius of the wound wire does not exceed a certain value.

Before joining the wire parts, which have a much greater length than width or thickness or diameter, in particular a length in the order of more than 100 times, in particular more than 1000 times or 10,000 times the maximum dimension of the wire in a direction transverse to the wire longitudinal axis, in particular perpendicular to the longitudinal axis of the wire, the end faces can be prepared so that the end faces represent plane, clean surfaces that allow an exact juxtaposition of the end faces without inclusion of impurities. The preparation of the end faces to have a plane, clean and only the material of the wire having surface can be achieved by cutting the wire parts to be connected transversely, in particular perpendicular to the wire longitudinal axis. This means that a short end piece of the respective wire parts can be cut off prior to joining in order to produce a smooth and clean surface on the end faces to be joined.

The cutting can be carried out in particular by laser beam cutting, preferably with ultrashort pulse lasers, for example a femtosecond laser. Ultrashort pulse lasers, such as the femtosecond lasers, are therefore particularly advantageous because they allow cold material to be cut by direct material sublimation, so that no material changes due to heat input and melting of the material in the region of the cut edge are to be feared.

As an alternative to laser beam cutting, the cutting can also take place by electrochemical material processing, wherein the material of the wire part to be cut is anodically oxidized and dissolved by a cathode and a suitable electrolyte. This also makes it possible to produce a clean and even cut surface and thus end face of the wire part to be joined.

The joining of the wire parts can be done by induction welding or induction soldering. Through induction welding or induction soldering, a sufficient amount of heat for the connection can be introduced in a locally limited manner.

When joining by means of soldering, a solder foil can be arranged between the end faces in order to provide the necessary solder material.

The wire parts can be fixed during the joining in the vicinity of the end faces to be joined in order to avoid bending of the ends of the wire parts by the amount of heat introduced. The free ends of the wire parts to be joined together may have a length in the range of up to 30 times, preferably up to 20 times and in particular up to 10 times the maximum dimension of the end faces or the maximum dimension transverse to the wire longitudinal axis. The fixing of the wire parts in the vicinity of their ends, whose end faces are to be connected to each other, can be done by mechanical clamping or stapling by spot welding or gluing. The spot welding or gluing should be done so that the fixation after connecting the wire parts can be easily solved again, without the wire parts are damaged. For example, adhesives can be used, which evaporate without residue with appropriate heat, such as adhesives, which are also used for fixing components in high-temperature soldering.

In order to avoid introduction of foreign substances during the joining process, welding or soldering can be carried out under a protective gas atmosphere, for example under an argon or helium atmosphere or, depending on the materials used, also under a nitrogen atmosphere. The inert gas atmosphere may be a local inert gas atmosphere, which is locally limited to the area of the joint. Alternatively, the protective gas atmosphere can also be set in a chamber in which the wire parts are completely accommodated.

As already mentioned, the inventive method for producing a wound on a coil wire in particular for brittle materials with a limited elongation at break, in which short wire parts can be produced by cutting, for example, from a plate. The elongation at break of such materials may be less than or equal to 5%, in particular less than or equal to 2.5%, preferably less than or equal to 1%. In particular, wires made of intermetallic compounds or alloys based on intermetallic compounds can be produced by the method according to the invention, which have a high strength but low deformability due to their particular type of bonding. Accordingly, the method can preferably be used for titanium aluminides and TiAl alloys whose main constituents are titanium and aluminum and whose microstructure has intermetallic phases with titanium and aluminum. In particular, their structure can predominantly have intermetallic phases with a proportion of more than 50 percent by volume.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings show in a purely schematic manner in FIG

1 a representation of a device for induction welding of ends of wires to be joined and in

2 a plan view of a part of the device 2 ,

Embodiment

Further advantages, characteristics and features of the present invention will become apparent in the following detailed description of an embodiment. However, the invention is not limited to this embodiment.

1 shows in a purely schematic, perspective view of an apparatus for welding wire ends by induction welding. The wire parts 1 . 2 , which are only partially shown for the sake of simplicity, are each in a guide arrangement with two parallel spaced guide blocks 4 arranged, with the end faces of the wire parts 1 . 2 at the junction 3 lie flat against each other or define a narrow gap between them.

The front sides of the wire parts 1 . 2 are before arranging the wire parts 1 . 2 in the guide arrangements by cutting the wire parts 1 . 2 transverse to the longitudinal direction of the wire parts 1 . 2 created with a flat and level surface. The cutting of the wire parts 1 . 2 can be done for example by laser beam cutting, in particular ultrashort pulse lasers, such as femtosecond lasers can be used, which allow cutting of the material by pure evaporation of material, so no melting of the cut material and thus no heat stress of the material takes place at the edge regions of the cutting edge. As an alternative to the laser beam shaving, the preparation of the end faces of the wire parts can also be carried out by separating a remainder of a wire part by electrochemical material processing, in which case the material is dissolved in the region of a cathode-connected electrode in the presence of an electrolyte by an anodic oxidation. This allows a flat, metallically bright surface at the parting surfaces of the wire parts 1 . 2 generate, which is suitable for a subsequent joining process.

The in the guide arrangement with the guide blocks 4 arranged wire parts 1 . 2 at the junction 3 lie flat against each other with their faces, are connected to each other in the illustrated embodiment by induction welding, wherein an induction coil 6 in the area of the joint 3 arranged around the joint and with an induction generator 7 connected is. Inductive heating causes the wire parts to melt 1 . 2 in the area of the joint 3 and for welding the end faces of the wire parts 1 . 2 ,

In order to avoid oxidation of the molten material during welding, and thus the incorporation of oxides at the joint 3 takes place, the welding can be erflogen under inert gas, but not the entire device with the wire parts 1 . 2 must be located within a protective gas atmosphere, even if this is of course a possibility, but it can be made a local inert gas atmosphere characterized in that inert gas from a protective gas reservoir 8th via a nozzle arrangement 9 in the area of the joint 3 is directed.

Like in the 1 it can be seen, are the wire parts 1 . 2 , which are welded together at their ends, during welding in the guide assembly via pressure cylinder 5 clamped so that they are fixed in position. Since the freely protruding ends of the wire parts 1 . 2 , whose end faces are welded together, can be kept short, can be a deformation of the ends of the wire parts 1 . 2 in the area of the joint 3 be avoided during the welding process. To set a suitable length of the free ends of the wire parts 1 . 2 can the guide blocks 4 the guide assembly to be mounted adjustably in the longitudinal direction of the male wire parts. In addition, also the distance of the guide blocks 5 be mutually changeable to different widths wire parts 1 . 2 to be able to record. In addition, the guide blocks 4 also be so flexible that not only different widths of wire parts 1 . 2 can be guided and held, but also wire parts 1 . 2 with different height. Furthermore, the gap for receiving the wire parts 1 . 2 between the guide blocks 4 also to different forms of the wire parts 1 . 2 be adapted, for example, to cylindrical wire parts 1 . 2 ,

The 2 shows in plan view parts of the device 1 , wherein for clarity, certain components have been omitted. Instead, is in 2 to see that the interconnected wire parts 1 . 2 after connecting on a spool 11 which are about a rotation axis 10 can rotate, as indicated by the arrow, can be wound up. Accordingly, a plurality of wire parts can be successively connected to each other at their end faces and the resulting long wire can on a corresponding coil 11 be wound up. This makes it possible also brittle materials that have only a limited elongation at break, such as intermetallic compounds or alloys based on intermetallic compounds, such as titanium aluminides and TiAl - alloys, in the form of one on a coil 11 coiled wire by adding individual wire parts 1 . 2 , which have been produced for example by cutting out of a plate, are joined together via joining at their end faces.

Although the present invention has been described in detail with reference to the embodiment, it will be understood by those skilled in the art that the invention is not limited to this embodiment, but rather modifications are possible in the manner that individual features can be omitted or other combinations of the features can be realized as long as the scope of protection of the appended claims is not abandoned. The present disclosure includes all combinations of the described individual features.

LIST OF REFERENCE NUMBERS

1

wire part

2

wire part

3

joint

4

guide block

5

pressure cylinder

6

induction coil

7

induction generator

8th

Inert gas reservoir

9

nozzle assembly

10

axis of rotation

11

Kitchen sink

Claims (10)

Method of making a coil on a coil ( 11 ) wound wire having a plurality of windings, so that the length of the wire is much larger than the diameter or a maximum dimension of a cross section of the wire transverse to the wire longitudinal direction, wherein in the method at least two wire parts ( 1 . 2 ) are provided, which are connected to end faces of the wire parts, which extend transversely, in particular perpendicular to the wire longitudinal axis, with each other, wherein the joining of the end faces is carried out by welding or soldering. A method according to claim 1, characterized in that the end faces of the wire parts are provided before joining by cutting the wire parts transversely to the wire longitudinal axis with a flat, clean surface. A method according to claim 2, characterized in that the cutting by laser beam cutting, in particular with an ultrashort pulse laser, preferably a femtosecond laser, or by electrochemical material processing. Method according to one of the preceding claims, characterized in that the joining takes place by induction welding or induction soldering. Method according to one of the preceding claims, characterized in that during the joining a solder foil is arranged between the end faces. Method according to one of the preceding claims, characterized in that the wire parts are fixed during joining in the vicinity of the end faces to be joined, in particular by clamping or stapling by spot welding or gluing. Method according to one of the preceding claims, characterized in that the joining under a protective gas atmosphere, in particular local inert gas atmosphere at the joint ( 3 ) he follows. Method according to one of the preceding claims, characterized in that the wire parts ( 1 . 2 ) are formed of a brittle material whose elongation at break is less than or equal to 5%, in particular less than or equal to 2.5%, preferably less than or equal to 1%. Method according to one of the preceding claims, characterized in that the wire parts ( 1 . 2 ) are formed from TiAl or a TiAl alloy whose main constituents are Ti and Al and whose microstructure exhibits intermetallic phases with Ti and Al, in particular predominantly intermetallic phases in the microstructure. Wire produced by a method according to any one of the preceding claims.

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