EP1748865B1 - Filler for joint and method for the production thereof - Google Patents

Abstract

The invention relates to a filler material for a thermal production of a joint or of a material layer metallically connected to the base material of or on objects of light metal and/or zinc alloys with a thermal conductivity of more than 110 W/mK, and to a method for producing the same with means for the preparation thereof in situ and/or storage. To improve the quality of the connection, it is provided according to the invention that the filler material is formed as unwindable filler wire, built up of a sheath optionally provided with a surface layer formed from polymer(s) and graphite and comprising aluminum and/or magnesium and/or zinc or a deformable alloy of these metals with a thermal conductivity of more than 110 W/mK and a core of compacted powder, whereby the core material comprises a metal powder and/or a powder of at least one metal compound and/or a non-metallic compound and/or an agent giving off gas at increased temperature and/or at least one component forming slag. The production is characterized by a filler wire production known per se, but with an optionally coated sheath of a ductile light metal or the like alloy, with a correctly positioned winding on coils and providing the same with a protection against moisture.

Description

The invention relates to an additional material for a thermal production of a joint connection or a metal support metallically connected to the base material of or on objects made of light metal and / or zinc alloys with a thermal conductivity of higher 110 W / mK,

Furthermore, the invention comprises a method for producing a filler material for bonding or application of, or on objects made of light metal and / or zinc or an alloy of these metals having a thermal conductivity of higher 110 W / mK with means for providing on site and / or Storage of the same.

Finally, the invention relates to the use of filler material, formed as a filler wire for a thermal production of a joint connection.

A joining is according to DIN 8593 a permanent bringing together of workpieces, the invention has a joining by welding or by soldering to the content. Fitting by welding in accordance with DIN 1910 of the subject invention relates to fusion welding with filler metal and brazing according to DIN 8505 relates to a hard joint brazing.

Joining of parts or objects or application of a material thereto by fusion welding or brazing with filler material has long been state of the art and is widely used in manufacturing technology.

When welding the cohesion is achieved by Stoffverelnigung, the parting line between two workpieces by fusing their materials is done with a filler and by Hifsstoffe, such as gases, welding powder or paste, can be promoted.

During soldering, the parting line between two workpieces becomes liquid Completely filled metal and so made a cohesive connection, Löthitfsstoffe or solder usually find use.

For joining parts with the desired high quality of the connection by welding or soldering, the materials or their properties are of great importance. In other words, not all materials or metals have sufficiently good welding or soldering properties.

The quality of a welded joint can be highly adversely affected by a high thermal conductivity and / or a high oxygen activity of the material and / or a surface tension of the liquid metal and / or the vapor pressure of a phase or the like.

It is known to the person skilled in the art that during joining or surfacing of aluminum parts and aluminum alloys with rod or solid wire electrodes, a connection of base material and weld metal often does not reach the edge of the same and in the outer zones of the weld material layer there is a region without metallic bond arises.

If, in order to reduce this bonding error, the welding energy is increased, the porosity in the weld metal increases or increases, which can lead to a mechanical weakening of the same.

In the case of soldering, despite soldering, there is often no sufficient penetration of solder into the gap between the parts or a connection of the same with the solder. These error phenomena are often associated with the high thermal conductivity of the materials and / or the melting and oxidation behavior of the solder and / or the Lötflächenpassivierung

Flux cored electrodes with a cladding of aluminum and a core of metal compound or alloy powder disclosed EP 1 197 288 The core material may contain some of the elements Si, Cu, Mg, Mn, Ba, Ti, Fe, Cr, Al, where Ba and / or manganese nitride should eliminate or reduce pore formation by hydrogen in the weld seam.

To overcome connection errors, it is also known to have a pulsating To use energy supply for welding or soldering, but this can usually only an energy input regulated, but not the energy distribution at the welding or soldering advantageously be formed such that the weld metal has up to the outer edge of a metallic bond with the base material or , the solder is distributed homogeneously in the parting line.

Here, the invention seeks to eliminate the deficiencies in the prior art in a thermal production of a joint or connected to the base material material support of or on objects made of light metal and / or Zinkleglerungen with a thermal conductivity of higher 110 W / mK and sets itself the goal to provide a filler which has improved suitability for welding and brazing of the above materials.

Furthermore, it is an object of the invention to provide a method for producing a duality preservation of a filler material for a joining of the type mentioned, with which a quality of the material connection can be increased.

Furthermore, the invention aims to indicate a particular use of a new, improved filler material.

The object of the invention is achieved in that the filler material as a rewindable cored wire, constructed of a sheath made of aluminum and / or magnesium and / or zinc or a deformable alloy of these metals with a thermal conductivity of higher 110 W / mK and a core of compacted Is formed, wherein the core material of a metal powder and / or a powder of at least one metal compound and / or a non-metal compound and / or a gas at elevated temperature emitting agent and / or at least one slag-forming component, and in that the outer surface of the filler wire a Layer which is formed from polymers, preferably organic polymers, in particular polytetrafluoroethylene (PTFE) and graphite.

The advantages achieved by the invention are essentially in the structure of the filler material and in the vote of the same with the base material or with the material properties.

It is essential to the invention that the outer surface of the filler wire has a layer which consists of polymers, preferably organic polymers,

In particular, polytetrafluoroethylene (PTFE) and graphite is formed, whereby a protective gas cover of the liquid metal improves and a current transfer are substantially improved in the cored wire.

The favorable effect of a graphite additive can be optimized if the volumetric proportion of graphite in the layer is 15% to 45%.

It has been found that in the case of a flux-cored wire with a coating of light metal or zinc alloys with a specific conductivity ρ of 0.027 to 0.2 μΩm, an unexpectedly high current concentration is present at the surface of the electrode, so that in the area of the energy input a cross section is substantially the same or In the outer zone increased heat penetration into the base material takes place. The formed of powder core of the cored wire conducts even at a high metal content of the core material, the electric current with energy input, as was found, in a much lower outlet. Thus, with a flux-cored wire according to the invention, the specific energy input in the heat range of the base material can be distributed and in this way an improved cohesive connection can be achieved with a weld up to the edge of the weld metal.

A distribution of energy or heat input is essentially dependent on the continuous metallic sheathing of the cored wire and can thus be adjusted.

If, as may further be provided, the filler wire has a filling level with core material of 5% to 52% in parts by weight, this can be advantageous, in particular, for use in joining light metals.

Intensive tests with aluminum and magnesium and alloys with these metals have shown that a filler wire according to the invention, especially if the core material comprises polymers, preferably organic polymers, in particular polytetrafluoroethylene (PTFE), substantially reduces the porosity of the weld metal and / or reduces the pore size.

When, as in a particular embodiment of the invention, the cored material of the cored wire comprises alkali metal compounds, for example, sodium and / or potassium compounds, especially fluorides and / or chlorides of alkali metals, a flux or capping agent, such as slag, which acts favorably on a metal compound can be created even if the individual compounds are not pre-melted.

The quality of a joining connection between aluminum and aluminum alloys can be optimized if the cored wire used for this purpose has a core material with a content of 8% by weight to 24% by weight, formed from metal powder and fluoride (e), and the jacket has a surface layer of polymer (s) and graphite.

The flux-cored wire has proved to be particularly suitable as a welding additive for the production of a fusion weld for the abovementioned materials, because protection and / or reaction gases can advantageously be formed by the core material in the arc, and a desired alloy composition of the weld metal is melt-metallurgically formed by adding metal powder can be.

If the cored wire is used as a soldering additive or solder for creating a solder joint, then this agent has the advantage of a central introduction of Löthilfesubstanzen directly into the parting line and can thereby significantly promote the formation of a material connection of the parts.

It may be favorable in view of a high quality of the solder joint, if the shell material of the filler wire has a lower target temperature than the (the) base material (s).

The further object of the invention in a method of the type mentioned is achieved when a metal strip of aluminum and / or magnesium and / or zinc or a ductile alloy each of these metals in a conventional manner bent in the longitudinal direction to a groove, charged with filler, formed into a tube and this to a diameter of more than 0.5 mm, however less than 3.5 mm, after which, after bending the filler-loaded channel to a tube, this tube is externally coated with a mixture of polymers, preferably organic polymers, in particular polytetrafluoroethylene (PTFE) and graphite, and subsequently to a smaller one Diameter of less than 2mm is further deformed, the cored wire produced in such a way wound on a bobbin and the wound coil (s) provided with a moisture protection stored and / or provided on site (will).

The advantages of the method according to the invention are essentially to be seen in the fact that the cored wire is produced from a sheath material with a non-ferrous base alloy with low strength, achieving a desired core density and a ready-to-feed form for supply to the welding or soldering device as far as the heat energy input region be created and during a possibly long-term storage substantially no changes in the often hygroscopic flux-cored wire components, which influence the use parameters or the quality of the joint connection done.

With particular advantage for a production and the technology of the compound used in this case can be provided that the filled pipe is brought to a diameter of less than 2.0 mm. In order to achieve a specific and / or targeted release of gas and / or to set a particular solution behavior of the core powder fractions, it may be advantageous if the filler or components thereof at least partially pretreated prior to introduction into the metal channel and / or homogeneously mixed as a powder (be ).

In a particularly advantageous embodiment of the invention, it is provided that polymers, preferably organic polymers, in particular polytetrafluoroethylene (PTFE), are added to the filler as a component and / or are applied to the outside of the filler wire. With this method, as surprisingly the skilled person showed, a pore formation, in particular such with large volumes, can be substantially reduced in the weld metal.

It has proved to be advantageous in the production of a joint compound when sodium and / or potassium and / or magnesium and / or calcium compound (s) are (are) added to the filler as component (s) for forming slag. As a result, the Flleßelgenschaften the filler and a cohesive connection of the parts of base material can be promoted.

In particular for alloying the forming material of the filler metal with respect to modified and desired mechanical properties of the same, it can be provided that the filler is incorporated as component (s) powder of metal and / or metal compounds and / or non-metal compounds.

In order to maintain the properties of the components of the filler throughout the manufacturing process unchanged or only with insignificant changes, it has proved to be advantageous if the filler wire is produced under conditions with respect to the air atmosphere reduced oxygen and / or reduced moisture content.

For an advantageous embodiment of the invention, in which the cored wire with a mass of 2 to 10 kg wound on a bobbin and one or more coil (s) in films or in containers airtight, optionally at reduced pressure, can be packed even with a longer Storage and larger stocking the quality of the filler material for a joint connection and the high quality of the cohesive connection itself remain.

In a promotion of the cored wire with increased contact pressure of the conveyor rollers, which can serve to improve contact, it can be provided that the bent to a gutter, acted upon with filler metal strip overlapped to form a tube and this is further processed.

In order to achieve desired high filling levels of Fülldrahtes with Pulverkemmaterial, according to the invention in a favorable manner bent to a gutter, acted upon with filler metal strip with a shock in the longitudinal direction to form a tube and this world to be processed.

It is essential to the invention that after bending the filler-loaded channel into a tube, this tube is externally coated with a mixture of polymers, preferably organic polymers, in particular polytetrafluoroethylene (PTFE) and graphite, and subsequently further deformed to a smaller diameter of less than 2 mm ,

Advantageously, on the one hand favorable conditions in the further deformation of the tube to filler wire with a small diameter created by a lubricating effect of the coating, on the other hand can by a graphite part desired current transition are promoted in the Füllfdraht.

A targeted and simple in the production process afubringen the layer can take place when the outer coating of the tube by means of the same carried out by a mixture of polymer (s) and graphite.

If, according to an embodiment of the invention, prior to winding the filler wire onto a bobbin, the layer is stack-wise surface-buffed, a desired layer thickness for welding or brazing can be created over the entire generation length of the wire with high accuracy.

Ultimately, the purpose of the invention by a use of filler material, as a cored wire, with a formed from polymer (s) and graphite surface layer, composed of a sheath of aluminum and / or magnesium and / or zinc or deformable alloy of these metals having a thermal conductivity of higher than 110 W / mK and a core of compacted powder, the core material consisting of a metal powder and / or a powder of at least one metal compound and / or a non-metal compound and / or a gas at elevated temperature and / or at least one slag forming component consists, for a thermal production of a joint or a metallically associated with the base metal material support of or on objects made of light metal and / or zinc alloys with a Wärmeleitfähigeit higher 110 W / mK met.

Surprisingly enough for a person skilled in the art, excellent quality results were obtained by using filler material as filler wire, with a surface layer formed of polymer (s) and graphite, composed of a sheathing of aluminum and / or magnesium and / or zinc or deformable alloy of these metals with one Wärmeleltfähigkeit of higher 110 W / mK and a core of compacted powder of at least one metal compound and / or a non-metal compound and / or a gas at elevated temperature emitting agent and / or at least one slag-forming component, for a thermal production of a joint of Parts of ceramic materials or parts of ceramic materials with metallic objects, in particular steel.

In this way, articles made of individual parts with completely different properties in the case of metallic bonding thereof can be economically produced in a simple manner.

Fig. 1 bis Fig. 3

Schweißgut auf einem Grundwerkstoff, erstellt mit Elektroden gemäß dem Stand der Technik

Fig. 4 bis Fig. 6

Schweißgut auf einem Grundwerkstoff, erstellt mit erfindungsgemäßen Fülldraht-Elektroden

Fig. 7

Schweißgut mit Poren auf einem Grundwerkstoff

Fig. 8

Schweißgut, hergestellt mit einer Fülidraht-Elektrode gemäß der Erfindung

Fig. 9

mittels erfindungsgemäßen Fülldraht-Elektroden verschweißte Teile

Fig. 10

Fülldraht mit einer überlappenden Ummantelung

Fig. 11

Fülldraht mit einem Stoß der Ummantelung

In the following the invention will be explained in more detail with reference to some results. The base material used was an AlMg5 alloy. The welds were done without impulse current technology. When using the same, in particular when the filler material according to the invention further improvements can be achieved. Show it:

Fig. 1 to Fig. 3

Welded material on a base material, created with electrodes according to the prior art

Fig. 4 to Fig. 6

Welded material on a base material, created with Fülldraht electrodes according to the invention

Fig. 7

Weld metal with pores on a base material

Fig. 8

Weld metal produced with a filler wire electrode according to the invention

Fig. 9

parts welded using flux-cored electrodes according to the invention

Fig. 10

Cored wire with an overlapping sheath

Fig. 11

Cored wire with a shock of the sheath

Out Fig. 1 is a Schweißgutauflage 1, made with a currently commercially available electrode on a base material 2, can be seen. An application smelting was carried out with a low electric current strength, whereby at a low level of shaving depth 11 in the base material 2 clear binding errors 21, 21 'are given between this and the material 1 for welding.

Fig. 2 shows a Schweißgutauflage 1 produced with an increased current strength, but otherwise similar. At a significantly increased melting or melting 11 of the weld 1 in the base material 2 by an increased energy input still binding error 21,21 'are given at the edges of the weld metal.

Even with a further increase in welding energy, such as In Fig. 3 shown, Bindefehier 21.21 'result between material to be welded 1 and base material. Due to an increased heat input, the Einschmeiztiefe are formed enlarged and increases the number and size of the pores 3. This is according to a professional opinion on a Outgassing of the liquid metal during solidification of the weld 1 due.

Out Fig. 4 is a welding layer 1, manufactured with inventive filler wire, see. Despite low electrical energy supply no binding errors are given in the outer binding area.

With an increased proportion of cladding of the filler wire with increased metal powder set in the core material and higher energy input is how Fig. 5 shows an enlarged Einschmelziefe 11 of the welding pad 1 at error-free bond between this and the base material 2 achieved.

Out Fig. 6 is a very high bondfehlierfreie melting depth 11 of the weld 1 in the base material 2 refer.

How through Fig. 4 to Fig. 6 is illustrated with a filler wire according to the invention by a choice of its geometric parameters and the Kernmateriatzusammensetzung a desired melting depth 11 in the base material 2 with a planned volume of weld metal 1 with appropriate electrical power supply error-free fabric compounds are produced as required.

In Fig. 7 a welding layer 1 with pores 3 is shown. The pores were formed during the solidification of the liquid welding filler due to the solubility jump for gases therein.

How out Fig. 8 can be removed, can be created with a core material according to the invention, which PTFE, or with a similar outside application, a cored wire, which results in a significant reduction in the proportion of pores 3 in the weld metal.

Fig. 9 shows welded parts 2,4, whose connection was made in the course of development work. A preparation of the two welding layers 1,1 '(A35, A36) was carried out with Füllwraht electrodes according to the invention, but with different geometrical and procedural parameters. Clearly the image can be taken from a two-sided defect-free fusion weld joint become.

In Fig. 10 shows the cross-section of a cored wire with a lap-sheath.

Fig. 11 illustrates a flux cored wire with a substantially end-to-end shock of the sheath.

Claims (13)

1. A filler for thermally producing a joint or an overlay of material metallically bond to a basic material of or on articles of light metal and/or of zinc alloys having a thermal conductivity of more than 110 W/mK, wherein the filler is formed as a cored wire capable of being wound-up, which is constituted by a sheath of aluminium and/or of magnesium and/or zinc or of a deformable alloy of these metals having a thermal conductivity of more than 110 W/mK, and a core of a compressed powder, wherein the core material consists of a metal powder and/or of a powder of at least one metal compound and/or of a non-metal compound and/or of an agent which emits a gas under an elevated temperature and/or of at least one slag forming component, characterised in that the outer surface of the cored wire comprises a layer formed of polymers, preferably organic polymers, particularly polytetrafluorethylene (PTFE) and graphite.
2. Filler according to claim 1, characterised in that the volume percentage of graphite in the layer is 15% to 45%.
3. Filler according to claim 1 or 2, characterised in that the cored wire has a filling ratio with core material, in percent by weight, of 5% to 52%.
4. Filler according to any of claims 1 to 3, characterised in that the core material comprises polymers, preferably organic polymers, particularly polytetrafluorethylene (PTFE).
5. Filler according to any of claims 1 to 4, characterised in that the core material comprises alkali metal compounds, for example sodium and/or potassium compounds, in particular fluorides and/or chlorides of alkali metals.
6. Filler according to claim 5, characterised in that the volume percentage of graphite in the layer is 15% to 45%.
7. Filler according to any of claims 1 to 6, characterised in that the cored wire comprises a core material having a percentage of 8% by weight to 24% by weight formed of a metal powder and fluoride(s) and a sheath having a surface layer of polymer(s) and graphite.
8. A method for the production of a filler for bonding or overlaying of or on articles according to claims 1 to 6, for bonding or overlaying of or on articles of light metal and/or of zinc or of an alloy of these metals having a thermal conductivity of more than 110 W/mK including means for making it available in place and/or for storing it, wherein a metal ribbon of aluminium and/or of magnesium and/or of zinc or of a ductile alloy of these respective metals is bent in a manner known per se in longitudinal direction into the form of a flute, is charged with a filler, is formed into pipe, which is brought to a diameter of more than 0,5 mm, but less than 3,5 mm, characterised in that the exterior of this pipe is coated by a mixture of polymers, preferably organic polymers, particularly polytetrafluorethylene (PTFE) and graphite, and is subsequently further shaped to a smaller diameter of less than 2 mm, then the cored wire, thus produced, is wound onto a bobbin in a stratified manner, and the spooled bobbin(s), provided with a moisture protection, is (are) stored and/or is (are) made available in place.
9. Method according to claim 8, characterised in that the outer coating of the pipe is effected by passing it through a mixture of polymer(s) and graphite.
10. Method according to claim 8, characterised in that the cored wire is produced under conditions of reduced oxygen content and/or decreased moisture content in comparison with the air atmosphere.
11. Method according to any of claims 8 to 10, characterised in that the cored wire is wound up on a bobbin with a mass of 2 to 10 kgs, and one or more bobbin(s) is (are) hermetically packed in foils or in containers, optionally under reduced pressure.
12. The use of a filler, formed as a cored wire according to claims 1 to 7, produced according to a method, which corresponds to claims 8 to 12, for thermally producing a joint or an overlay of material metallically bond to a basic material of or on articles of light metal and/or of zinc alloys having a thermal conductivity of more than 110 W/mK.
13. Use of a filler, formed as a cored wire according to claims 1 to 6, produced according to a method, which corresponds to claims 7 to 9, for thermally producing a joint of parts of a ceramic material or of parts of ceramic materials with metallic articles, particularly of steel.

Images