DE102020213303A1 - Process for treating surfaces - Google Patents

Abstract

The invention relates to a method for treating surfaces (12) of metal parts (34) or of extruded profiles (10), the surfaces (10) serving as a joining zone (24) for a metal-plastic connection (30) in a subsequent process step . On the surface (12) forming the joining zone (24), a) targeted surface defects are produced and/or b) the surface (12) of the extruded profile (10) is structured and/or c) macroscopic structures (36) are formed introduced into the surface (12). This improves the formation of the metal-plastic connection (30) between a plastic part (32) and a metal part (34) or an extruded profile (10). The invention also relates to a metal-plastic connection (30) between a plastic part (32) and an extruded profile (10), the surface (12) of which forming the joining zone (24) is produced according to the method used in the production of the extruded profile (10 ) is pretreated.

Description

technical field

The invention relates to a method for treating the surfaces of metal parts or extruded profiles, with the surfaces serving as joining zones for a metal-plastic connection in a subsequent process step. Furthermore, the invention relates to a metal-plastic connection between a plastic part and an extruded profile, whose surface forming the joining zone is pretreated according to the method during the production of the extruded profile.

State of the art

DE 10 2010 005 489 A1 relates to a strand component and a method for its manufacture. The extruded component is produced in particular by extrusion, continuous casting, roll forming or the like, a cross-sectional profile of the extruded component being formed using a shaping tool and at least one contour element being produced in an outer wall of the extruded component during shaping. The contour element is only produced over partial lengths of the strand component in its outer wall. In order to achieve a micro form fit, the surface can be roughened by sandblasting or the like.

DE 10 2013 020 527 A1 has a hybrid component and a method for its production as its subject. A hybrid component is disclosed, in particular an instrument cross member for a motor vehicle with a metal profile part which has a surface structure at least in regions. In its area, the metal profile is at least partially provided with plastic, the surface structure of the metal profile being formed by a longitudinal profile running in the direction of extent, which is provided with a transverse profile. The longitudinal profiling can have a plurality of longitudinal grooves, which each form undercuts.

DE 10 2016 120 355 A1 relates to a composite component for a motor vehicle. The composite part comprises a first section and a second section connected thereto. The first section has a metallic material, the second section a plastic. The first portion has a first base portion and protrusions provided on the first base portion and extending from the first base portion toward the second portion. Undercuts are anchored in the second section to effect the connection between the first section and the second section.

US 2015/0328815 A1 relates to a method for extruding a microstructure.

Direct connections between metal and plastic components are mostly based on a modification of the interface of the components, with which the connection properties are defined. Common methods are chemical pre-treatment processes such as etching or the application of an adhesion promoter layer. Mechanical processes include, for example, embossing or blasting with abrasive media, alternatively, machining processes are also conceivable. Another tool for surface modification is the laser, which can be used to create different surface structures. The joining process follows the surface pre-treatment. The molten plastic component is brought into contact with the metal in such a way that the surface structure of the metallic joining partner is completely filled. As soon as the liquid plastic solidifies on the metal component or, in the case of duroplastics, crosslinks, the connection is complete.

The extrusion process is an economical manufacturing process for the manufacture of profile structures. In principle, all metals can be extruded, but aluminum alloys make up the majority. Areas of application for extruded profile parts range from structural components for vehicle bodies to construction profiles and heat sinks to window frames. In the extrusion process, attempts are usually made to achieve the best possible surface quality.

Presentation of the invention

1. a) gezielt Oberflächendefekte erzeugt werden und/oder
2. b) eine Strukturierung der Oberfläche des Strangprofils erfolgt und/oder
3. c) makroskopische Strukturen in die Oberfläche eingebracht werden,

die eine Verbesserung der Ausbildung der Metall-Kunststoffverbindung zwischen einem Kunststoffteil und einem Metallteil oder einem Strangprofil bewirken.According to the invention, a method for treating the surfaces of metal parts or extruded profiles is proposed, with the surfaces serving as joining zones for a metal-plastic connection in a subsequent process step and on the surface forming the joining zone

1. a) targeted surface defects are generated and / or
2. b) the surface of the extruded profile is structured and/or
3. c) macroscopic structures are introduced into the surface,

which bring about an improvement in the formation of the metal-plastic connection between a plastic part and a metal part or an extruded profile.

The solution proposed according to the invention makes it possible for the surface to be finished during production, in particular of extruded profiles, in such a way that, in contrast to a high surface quality that can otherwise be achieved, microscopic roughness or macroscopic structures are introduced into the surface in a targeted manner, which result in a specific surface enlargement effect that promote the formation of a metal-plastic connection between a polymer part and a metallic component, in particular an extruded profile.

According to the solution proposed according to the invention, microscopic roughnesses are produced on or in the surface according to a) and/or b). The roughness is in the range between 1 µm and 500 µm (roughness depth). The superimposition of larger structures (1 µm to 1 mm) with fine structures (1 µm to 100 µm) is particularly advantageous.

In a development of the method proposed according to the invention, the macroscopic structures according to c) are introduced into the surface as undercuts, depressions or bulges. For example, macroscopic structures can be created by the die during extrusion, for example a dovetail structure with undercuts.

In the method proposed according to the invention, the macroscopic structures can be introduced into the surface in a regular orientation or in a stochastic distribution.

• - tropfenförmige Aufwürfe,
• - offen Poren,
• - Risse in der Oberfläche,
• - Riefen oder Werkzeuglinien,
• - Säume rekristallisierte Körner auf einer Profilaußenseite oder
• - Orangenhauteffekte

ausgeführt.In a further development of the method proposed according to the invention, the surface defects in the surface of the extruded profile or the metal part according to a) are

• - teardrop-shaped mounds,
• - open pores,
• - cracks in the surface,
• - Scratches or tool lines,
• - Rims recrystallized grains on a profile outside or
• - Orange peel effects

executed.

In a further development of the method proposed according to the invention, the surface is structured according to b) by means of a laser, in particular by means of an ultra-short pulse laser.

Alternatively, in the method proposed according to the invention, structuring of the surface of the extruded profile according to b) can be achieved by embossing, grinding, milling, by a coating or by additive or chemical methods.

In one embodiment of the method proposed according to the invention, chaotic structures according to b) are produced on the surface by breaking up the surface in the kneaded state of the cooling material of the extruded profile or the metallic component with a nail plate performing a rotational movement and/or a transverse movement. With such a tool placed on the surface to be pre-treated, undercuts can be produced in the micro range, which are in an arbitrary, d. H. irregular stochastic patterns can be executed and which significantly increase the surface area pretreated in this way.

In the method proposed according to the invention, the transverse movement and/or the rotational movement of the nail plate take place relative to the conveying of the extruded profile or the metal component in the conveying direction.

In a modification of the method proposed according to the invention, chaotic structures can be produced on the surface according to b) by breaking up the surface in the kneaded state of the cooling material of the extruded profile or the metal part using a plow that can be placed on the surface and removed from it.

In the method proposed according to the invention, with continuous movement of the extruded profile in the conveying direction, a continuous structure can be produced by means of a roller having a profile on the circumference, which is placed on the surface to be pretreated when the extruded profile is conveyed in the conveying direction.

The method proposed according to the invention makes it possible to produce macroscopic structures, for example dovetail geometries arranged in parallel, tooth profiles or pin geometries. Trench geometries (U-shape, V-shape), teardrop-shaped trench structures or T-groove shape or other cross-sectional configurations are also conceivable.

In addition, the invention relates to a metal-plastic connection between a plastic part and an extruded profile, the surface forming the joining zone according to the method in the production of the extruded profile for spe cific enlargement of the surface is pretreated.

Advantages of the Invention

The solution proposed according to the invention can be used to specifically influence the surface, in particular during the extrusion of extruded profiles, such that areas of the surface that serve as joining zones for metal-plastic connections in subsequent process steps can be produced directly in the extrusion process of the extruded profile. This means that the surface of the extruded profiles is specifically provided with a structure that is suitable for entering into a permanent bond with the plastic. Structures required for this can, on the one hand, have a microscopic roughness; alternatively, there is also the possibility of forming macroscopic structures, for example undercuts, depressions or bulges. In the method proposed according to the invention, the surface of the extruded profile can be pretreated by suitable tool modifications and/or modifications to the pressing process. In the classic extrusion process, the aim is usually to avoid surface defects. However, in the solution proposed according to the invention, surface defects are produced in a targeted manner, for example pickups, open pores, surface cracks, grooves, tool lines in the microscopic and macroscopic size range, as well as PCG defects or an orange peel effect.

The specific surface area of the metallic joining partner of the metal-plastic connection is increased both through the targeted generation of surface defects and through the structuring of the surfaces proposed according to the invention, as well as through the introduction of macroscopic structures into the surface, which increases the strength of a hybrid connection in shape a plastic-metal connection. By increasing the temperature and the complete penetration of the melted plastic into the surface defects, structured areas or macroscopic structures, an excellent strength of a metal-plastic connection can be achieved by enlarging the surface and completely filling it with the plastic material.

With the solution proposed according to the invention, both regularly oriented structurings can be produced, as well as structurings that include chaotic structures with many undercuts. Suitable, modified tools, for example rotating plate bodies with a mandrel arrangement, can be used to break up the surface while the cooling extruded profile is still in the kneadable state. The regularity of the structures produced in the surface to be treated can be increased by the tool, in the form of a rotating nail plate or a plow or the like, carrying out additional, overlapping movements. When using a tool, such as a nail plate, its rotational movement can be superimposed by a transverse movement. As a result, structures are produced in the extruded profile transported past the tool in the direction of conveyance, which enable a considerable increase in the surface area in the area of the joining zone of the metal-plastic connection.

Due to the structuring process integrated into the extrusion process, the otherwise downstream structuring process can be omitted, as well as all the associated handling, storage and cleaning steps. A faster and more cost-effective process sequence is thus possible. With the solution proposed according to the invention, macroscopic structures (via a matrix) with microscopic structures (for example surface defects) can be realized comparatively easily and in one work step.

character list

Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

• 1 eine perspektivische Ansicht eines Strangprofils mit einer makroskopischen Struktur,
• 2 eine Metall-Kunststoff-Verbindung zwischen einem Kunststoffteil und einem metallischen Teil mit einer makroskopischen Struktur,
• 3 eine Draufsicht auf einen strukturierten Bereich eines Strangprofils,
• 4 eine Seitenansicht des Strangprofils gemäß 3,
• 5 eine schematische Darstellung eines Werkzeugs in Gestalt einer Nagelplatte zur Erzeugung chaotischer Strukturen auf der Oberfläche des Strangprofils und
• 6 die Darstellung eines Pflugs zum Aufbrechen der Oberfläche des erkaltenden Materials eines Strangprofils sowie eine Darstellung einer eine Profilierung am Umfang aufweisenden Rolle.

Show it:

• 1 a perspective view of an extruded profile with a macroscopic structure,
• 2 a metal-plastic connection between a plastic part and a metallic part with a macroscopic structure,
• 3 a plan view of a structured area of an extruded profile,
• 4 a side view of the extruded profile according to FIG 3 ,
• 5 a schematic representation of a tool in the form of a nail plate for generating chaotic structures on the surface of the extruded profile and
• 6 the representation of a plow for breaking up the surface of the cooling material of an extruded profile and a representation of a roller having a profile on the circumference.

Embodiments of the invention

In the following description of the embodiments of the invention, the same or similar elements are denoted by the same reference symbols, with a repeated description of these elements being dispensed with in individual cases. The figures represent the subject matter of the invention only schematically.

1 shows a macroscopic structure of an extruded profile with dovetail-shaped undercuts.

1 an extruded profile 10 can be seen in a perspective view, the surface 12 of which has a structuring 14 . The underside of the extruded profile 10 opposite the surface 12 is identified by reference number 13 . The structuring 14 of the surface 12 of the extruded profile 10 as shown in 1 comprises a parallel arrangement 22 of a plurality of groove-shaped depressions which are designed in dovetail geometry 90 and have undercuts 16 . The undercuts 16 are in the production of the extruded profile 10 according to the illustration in 1 already incorporated into the surface 12, while the underside 13 of the extruded profile 10 is essentially unprocessed. The extruded profile 10 is a metal part 34. The extruded profile 10 is conveyed in a conveying direction 60 (cf. representation of 5 and 6 ) promoted.

From the perspective view according to 1 shows that a longitudinal direction of the extruded profile 10 is identified by reference number 18 and a transverse direction running perpendicular thereto bears reference number 20 . The surface 12, which includes the groove-shaped undercuts 16 running in a parallel arrangement 22, forms a joining zone 24 of a 2 shown metal-plastic compound 30.

From the one mentioned 2 shows such a metal-plastic compound 30 in more detail. The metal-plastic connection 30 includes a plastic part 32 which is joined to a metal part 34 in the form of an extruded profile 10 . According to the illustration 2 It follows that the surface 12 of the extruded profile 10 shown there, ie of the metal part 34, has a macroscopic structure 36. The macroscopic structure 36 as shown in 2 is designed as a tooth profile 38 which includes a number of individual teeth 40 . The individual teeth 40 are shown here in a regular orientation 46, each with a tooth flank 42 which is oriented in relation to the surface 12 of the extruded profile 10 at a tooth angle 44, which can be 90°, for example.

According to the illustration 2 It follows that the metal-plastic connection 30 shown there, made up of the plastic part 32 and the metal part 34, is subjected to a load introduction 50, indicated by the arrows indicating a tensile force.

Instead of the in 2 Tooth profile 38 shown as macroscopic structure 36 can also be designed as macroscopic structures 36 with any other geometries that promote a material connection. If the plastic part 32 is heated during joining with the joining zone 24 of the metal part 34, ie the extruded profile 10, an improvement in the metal-plastic connection 30 in the area of the joining zone 24 is achieved as a result of the increased viscosity.

The representations according to 3 and 4 tab-like metal parts 34 can be seen, each having structured areas 52 .

At the in the 3 and 4 Metal parts 34 shown in top view and in side view are flat strips. The structured areas 52 can be produced, for example, using etching methods or using a treatment with a laser, in particular an ultra-short-pulse laser. The structured areas 52 can also be produced via grooves 56, i.e. tool lines, or as cracks 58 in a regular orientation 46 or in a stochastic distribution 48 within the structured areas 52 on both sides, either offset from one another or opposite one another (as in 4 shown) are formed. The structured areas 52 can increase the specific surface area of the metal part 34 embodied as a flat strip. As can be seen from the representations according to the 3 and 4 shows, there are non-structured areas 54 next to the structured areas 52 either on the top 12 or on the top and bottom 12, 13 of the metal part 34. Depending on the requirement or space required for the formation of a metal-plastic connection 30, as in 2 As shown, the size of the structured areas 52 can be designed.

Of the 5 a nail plate 64 can be seen as an example and diagrammatically. In addition to a targeted provocation and exploitation of surface defects or surface defects for the pre-treatment of the joining zone 24, in-line structuring can also be carried out using additional tool components, such as an in 5 schematically illustrated nail plate 64 and an in 6 illustrated plow assembly or a profiled role. Continuous structures can be embossed into the surface 12 of the extruded profiles 10 by such tools. Another way to be special Creating chaotic structures with many undercuts 16 is, for example, breaking up the surface 12 while the cooling metallic material is still in the kneadable state, for example with the aid of an in 5 schematically indicated nail plate 64 or an in 6 illustrated plow 76 or one in 6 shown, provided with a profile 82, rotatable roller 80.

The schematic in 5 Nail plate 64 shown comprises a plate body 66, on the underside 13 of which a mandrel assembly 68 is located. If the nail plate 64, the drive of which is not shown here in detail, is set in a rotary movement 72 as part of a pivoting movement after completing a contact movement 74 on the surface 12 of the extruded profile 10, and a transverse movement 70 of the plate body 66 of the nail plate 64 is superimposed on this rotary movement 72 , a structuring 14 can be produced on the surface 12 in a stochastic distribution 48 . The structuring 14 of the surface 12, which forms the later joining zone 24 in which the metal-plastic connection 30 is made, has a stochastic distribution 48 of the undercuts 16, which is further supported by the fact that the extruded profile 10 moves in the conveying direction 60 moved on a conveying device 62, only indicated schematically, within the plane of the drawing. This means that when the rotating mandrel arrangement 68 is placed on the surface 12 of the extruded profile 10, a chaotic arrangement of undercuts 16 and accordingly a specifically enlarged surface 12 on the extruded profile 10 can be produced.

As in 5 indicated, the plate body 66 of the nail plate 64 with the mandrel arrangement 68 can also be turned off from the surface 12 to be treated by, for example, 90° in accordance with the on/off movement 74 .

Another way of breaking up the surface 12 of the cooling material of the extruded profile 10 and creating a structure 14 is to treat the surface 12 with a plow 76 or a plow share 78, which, when applied to the surface 12, which will later become the joining zone 24 forms, tool lines are generated. If the plow 76 or the ploughshare 78 is arranged in a stationary manner, the tool lines or the grooves 56 are generated by the conveying movement of the extruded profile 10 in the conveying direction 60 by the conveying device 62 .

Alternatively, there is the possibility of a structure 14 on the surface 12, d. H. the subsequent joining zone 24, applied by a roller 80. The roller 80 is able to perform an on/off movement 74 on the surface 12 of the extruded profile 10 and includes a profiling 82 on its circumference 84 structuring of the surface 12, d. H. their specific surface area increase.

In addition to the procedures for generating microscopic roughness, the macroscopic structures 36 can be generated in the surface 12, for example in 1 indicated dovetail geometry 90 can be formed directly in the production of the extruded profile 10 in the surface 12. Furthermore, structuring 14 can be produced in the surface 12 of the extruded profile 10, which reduces the shrinkage of the plastic (cf. plastic part 32 according to 2 ) make use of, and thereby particularly intimate metal-plastic connections 30 arise.

Due to the solution proposed according to the invention, the joining zone 24 can be prepared directly in the pressing process of the extruded profile 10 for metal-plastic connections 30 to be formed later. This means that the surface 12 of the extruded profiles 10 can be provided with a structuring 14 in a targeted manner. The structures required for this are distinguished on the one hand by a microscopic roughness and on the other hand by the formation of macroscopic structures 36 .

Contrary to the usual procedure of achieving surfaces 12 that are as smooth as possible, the method proposed according to the invention aims at the opposite and provokes surface defects which are normally to be avoided in the production of classic extruded profiles. Such surface defects are, for example, pickups, open pores, cracks 58, tool lines/grooves 56, PCG defects or orange peel effects.

With the method proposed according to the invention, the surface structuring in the microscopic and macroscopic range can be used to increase the specific surface area, which considerably improves the quality of a metal-plastic connection.

For example, while microscopic structures can be formed in the order of magnitude of roughness between 1 μm and 500 μm (measured surface roughness), coarser structures can be designed with a roughness between 100 μm and 1 mm. Particularly favorable effects can be achieved by superimposing finer structures (1 µm to 100 µm) on coarser structures of a size between 100 µm and 1 mm. In addition to the above for macroscopic structures already In addition to the above-mentioned dovetail geometries 90 and tooth profiles, pin geometries are conceivable, as are trench geometries in a U or V shape, teardrop-shaped trench structures or T-groove shapes.

The surface defects that are present or are created in the surface 12 of the extruded profile 10 can be drop-shaped bulges (pick-ups) that run parallel to the extraction direction. In general, the length of such a droplet-shaped bulge varies from 0.5 µm to 3 mm and can be found anywhere on the surface. The size of these drop-shaped bulges depends on the process parameters. Another surface defect, in addition to open pores, cracks 58 in the surface 12, grooves 56 or tool lines, are seams of recrystallized grains on the outside of profiles, which are also referred to as PCG defects (peripheral coarse grain defect). A fringe of recrystallized grains forms on the outside of profiles, since the deformation speed and the local degrees of deformation are higher here than in the center of the corresponding profile.

The invention is not limited to the exemplary embodiments described here and the aspects highlighted therein. Rather, within the range specified by the claims, a large number of modifications are possible, which are within the scope of expert action.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102010005489 A1 [0002]
• DE 102013020527 A1 [0003]
• DE 102016120355 A1 [0004]
• US 2015/0328815 A1 [0005]

Claims (13)

Method for treating surfaces (12) of metal parts (34) or of extruded profiles (10), the surfaces (12) serving as a joining zone (24) for a metal-plastic connection (30) in a subsequent process step, characterized in that that on the surface (12) forming the joining zone (24) a) surface defects are produced in a targeted manner and/or b) structuring of the surface (12) of the extruded profile (10) takes place and/or c) macroscopic structures (36) in the surface (12) are introduced in such a way that the formation of the metal-plastic connection (30) between a plastic part (32) and a metal part (34) or an extruded profile (10) is improved. procedure according to claim 1 , characterized in that according to a) and / or b) microscopic roughness or structures are produced on / in the surface (12), preferably in the order of between 1 micron to 500 microns. procedure according to claim 1 , characterized in that the macroscopic structures (36) according to c) are introduced into the surface (12) as undercuts, depressions or bulges. procedure according to claim 3 , characterized in that the macroscopic structures (36) in the surface (12) are introduced in a regular orientation (46) or in a stochastic distribution (48). procedure according to claim 1 , characterized in that the surface defects in the surface (12) of the extruded profile (10) or the metal part (34) according to a) as - drop-shaped bulges - open pores - cracks (58) in the surface (12) - grooves (56) or tool lines, - fringes of recrystallized grains on a profile outside (PCG defects) or as - orange peel effects. procedure according to claim 1 , characterized in that a structuring of the surface (12) according to b) is carried out by means of a laser, in particular by means of an ultra-short pulse laser. procedure according to claim 1 , characterized in that a structuring of the surface (12) according to b) is carried out by embossing, grinding, milling, coating or additive or chemical processes. procedure according to claim 1 , characterized in that to produce chaotic structures according to b) on the surface (12), breaking up the surface (12) in the kneaded state of the material of the extruded profile (10) or the metallic component (34) with a rotational movement (72) and /or a transverse movement (70) executing nail plate (64). procedure according to claim 8 , characterized in that the transverse movement (70) and/or the rotational movement (72) of the nail plate (64) takes place relative to the conveying of the extruded profile (10) or the metallic component (34) in the conveying direction (60). procedure according to claim 1 , characterized in that according to b) chaotic structures are created on the surface (12) by breaking up the surface (12) in the kneaded state of the cooling material of the extruded profile (10) or the metal part (34) by means of a carried out by this detachable plow (76, 78). procedure according to claim 1 , characterized in that according to b) with continuous movement of the extruded profile (10) in the conveying direction (60), a continuous structure is produced by means of a profiling (82) on the circumference (84) having roller (80). procedure according to claim 1 , characterized in that according to c) the macroscopic structures (36) are designed as dovetail geometries (90) arranged in a parallel arrangement (22), as a tooth profile (38) or trench geometries in a U shape, V shape, drop-shaped trench structures, T-slot shapes . Metal-plastic connections (30) between a plastic part (32) and an extruded profile (10), whose surface (12) forming the joining zone (24) according to the method according to one of Claims 1 until 12 is pretreated in the production of the extruded profile (10).

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