Method for producing a composite material of metal and plastic to form a plastic-metal hybrid component, and use of the hybrid component produced according to the method.

Abstract

A method for producing a composite material of metal and plastic to form a plastic-metal hybrid component, in which macroscopic undercuts with microscopic undercuts having stochastically random roughness shapes and depths are introduced into the metal surface by means of short-pulse laser radiation to improve the adhesion between the metal surface and at least one plastic component, wherein the shapes and depths of the laser structuring of the metal surface are produced by changing the guidance and / or speed of the laser beam movement and simultaneously adjusting the power and / or the repetition rate of the short-pulse laser radiation, and the stochastically random roughness shapes are each at least partially filled with the at least one plastic component in an injection molding process such that the latter is gripped in the macroscopic and / or microscopic undercuts.wherein, following the roughening of the metal surface prior to the injection molding process of the at least one plastic component, at least the roughened surface of the metal is heated to a temperature which, in the processing range from room temperature to 100°C, is above the processing temperature of the at least one plastic component.

Description

[0001] The invention relates to a method for producing a composite material of metal and plastic to form a plastic-metal hybrid component.

[0002] In a process known from JP 2014-051041 A, macroscopic and / or microscopic undercut-like slits are introduced into the metal surface in a first process step to roughen it using short-pulse laser radiation in order to improve the adhesion between a metal surface and at least one plastic component. The concave opening area of ​​these slits, both in plan view and in longitudinal section, is intended to have a repeating, geometrically precisely defined shape. For the opening area of ​​the slits to be introduced into the metal surface, defined, always repeating shapes such as circle, ginkgo leaf shape, boomerang shape, ellipse shape, square shape, polygon shape, or the like are specified in plan view, and for the longitudinal section of the slits, triangular shape, quadrilateral shape, or trapezoidal shape are specified.In a second process step, the slots precisely formed in the metal surface are then at least partially filled with the at least one plastic component in an injection molding process, so that improved adhesion between the latter and the slots in the metal surface is achieved.

[0003] From DE 10 2011 100 449.5 A1, a method for producing a composite body from at least one prefabricated metal component and at least one plastic component is also known, in which, for a surface of the metal component that is to be brought into contact with the plastic component and in which a toothing arrangement with a plurality of toothing elements arranged at a distance from each other is to be embossed, and from which the individual toothing elements are subsequently to be bent out of the surface of the metal component by means of a bending edge, forming a meshing element, the profile of the individual toothing elements of the toothing arrangement to be bent out of the surface of the metal component and / or their number and / or their distribution within the toothing arrangement and / or their position in space (x, y,The force flow-oriented design of the gear elements (z coordinates) and / or their area and / or surface structure and / or roughness is determined by means of numerical simulation according to the predicted static and / or dynamic forces acting on the composite body at each positive-locking connection of the composite body. Then, the multitude of gear elements of the gear arrangement are profiled according to the numerical simulation, spaced apart from each other, and aligned and imprinted into the surface of the metal component. Each gear element is then bent out of the surface of the metal component around the bending edge into its force-flow-oriented position in space, as determined by the numerical simulation. Finally, the metal component and the plastic component are positively connected to form the composite body. Subsequently, the metal component, from which the multitude of gear elements of the gear arrangement have been bent,fixed in an injection mold and injected into the plastic component of the composite body using a standard injection molding process onto the surface of the metal component, from which the multitude of gear elements are bent out, whereby each gear element of the gear arrangement is embedded in the plastic of the plastic component injected onto the metal component in its force-flow-oriented position in space, as predetermined by numerical simulation, and firmly anchored in it when the plastic of the plastic component solidifies.

[0004] German patent DE 10 2007 023 418 B4 describes a method for roughening component surfaces, particularly those made of metal, plastic, or ceramic, to improve the adhesion of thermally applied spray coatings. This method involves roughening the surface by creating microscopic undercuts. Specifically, pulsed laser beams with angles of inclination in the range of 20° to 80° are used to create inclined pockets on the surface. These pockets are dimensioned such that at least one edge forms an undercut relative to the metal surface. Furthermore, the surface is treated, at least in certain areas, multiple times with pulsed laser beams exhibiting different direction angles, angles of inclination, and / or different laser energies. The patent describes it as advantageous for the coating quality that the spray jet should be directed across the surface at the same angle as the pockets.For this purpose, the mold pockets should be formed parallel to each other with only one undercut edge relative to the surface. The deeper the mold pockets, the more precisely a suitable spray jet angle must be defined. The tolerances for the angle setting decrease accordingly. An unsuitable spray jet can therefore lead to incomplete filling of the mold pockets, which negatively affects or reduces the adhesion strength of the sprayed coating.

[0005] German patent DE 10 2006 004 769 A1 discloses a known method for roughening metal surfaces to improve the adhesion of thermally sprayed coatings. In a first process step, recesses or depressions are created in the surface by a material removal or abrasion treatment, so that the protruding metal forms raised microstructures, in particular projections, grooves, protrusions or bulges. In at least a second process step, these microstructures are further processed by deformation and / or fracturing such that a significant proportion of the structures form undercuts with respect to the surface.

[0006] German patent application DE 10 2008 040 782 A1 further discloses a known method for manufacturing a component assembly, particularly for automotive applications, comprising at least one first component with a first contact surface and at least one second component with a second contact surface adjoining the first contact surface, wherein a surface structure is generated on the first contact surface of the first component by means of a laser such that it has a microstructure superimposed on a nanostructure. After the surface structuring of the first contact surface of the first component, it is positively joined to the second component, which is made of plastic material, in particular a thermoplastic material, by at least partial overmolding of the first component with the second component.

[0007] DE 10 2011 111 745 A1 further discloses a control housing module for an internal combustion engine consisting of a metal-plastic hybrid composite, which has at least one metal insert, wherein the rib structure consists of injection-molded reinforcing ribs made of a thermoplastic polymer comprising short fibers of a reinforcing material with a volume fraction of at least 305.

[0008] Furthermore, a method for producing a composite part reinforced by a profile hollow body is known from DE 10 2010 055 824 A1, wherein the following process steps are to be carried out: 1. Providing a profile body, 2. Inserting the profile body into a cavity of an injection mold, 3. Shaping the composite component by injecting plastic material into the cavity, wherein the profile hollow body is supported during injection by a reinforcing medium in the inner volume of the profile hollow body, 4. Curing of the injected plastic material.

[0009] From DE 10 2009 028 583 A1, a method for producing a component composite is also known, comprising a first component with a first contact surface, wherein the first contact surface is provided with a surface structure having a microstructure superimposed on a nanostructure, and at least one second component with a second contact surface, wherein a medium, in particular an adhesive layer, is applied between the two contact surfaces for the metallurgical bonding of the two contact surfaces. The surface structure on the first contact surface or on both contact surfaces is generated by means of electromagnetic radiation.

[0010] Finally, DE 10 2011 121 545 B4 describes a process for producing a chemically modified metal- <oder Metalllegierungsoberfläche oder Metalloxid- oder Metalllegierungsoxidschicht auf der Oberfläche, die Oberflächenstrukturen mit Abmessungen im Sub-Mikrometerbereich aufweist, beschrieben, wobei die gesamte Oberfläche des Metalls oder der Metalllegierung oder der Metall- oder der Metalllegierungsoxidschicht auf dem Metall oder der Metalllegierungsoxidschicht, auf der die Strukturen zu erzeugen sind und die für eine Laserbestrahlung zugänglich sind, mit einem gepulsten Laserstrahl in einer Atmosphäre aus einem mit der Oberfläche reagierenden Gas oder Gasgemisch ein- oder mehrmals auf solche Weise abgetastet, das benachbarte Lichtflecke des Laserstrahls lückenlos aneinander stoßen oder sich überlappen und ein bestimmter Bereich einer vorgegebenen Relation zwischen Verfahrensparametern eingehalten wird.

[0011] The present invention is based on the novel objective of providing a method of the type mentioned at the outset with which a highly resilient, robust plastic-metal hybrid component can be produced that is extremely insensitive with regard to the surface cleanliness of the metal before processing and with regard to stresses caused by temperature changes and corrosion.In particular, it should be ensured that, in order to optimize the bond strength of the plastic-metal hybrid component to be joined, premature freezing of the at least one plastic component is avoided during injection molding onto the roughened metal surface, and that maximum adhesion stability of the at least one plastic component to the structured metal surface is guaranteed.

[0012] This problem is solved according to the invention by the entirety of the features of the method according to claim 1. Further developments of the method according to the invention are described in the dependent claims.

[0013] According to the invention, to improve the adhesion between a metal surface and at least one plastic component, macroscopic undercuts with microscopic undercuts of stochastically random roughness shapes and depths are introduced into the metal surface by means of short-pulse laser radiation. The shapes and depths of the laser structuring of the metal surface are generated by changing the guidance and / or speed of the laser beam movement and simultaneously adjusting the power and / or repetition rate of the short-pulse laser radiation. The stochastically random roughness shapes are then at least partially filled with the at least one plastic component in an injection molding process such that the latter is gripped in the macroscopic and / or microscopic undercuts.wherein, following the roughening of the metal surface before and / or during the injection molding process of the at least one plastic component, at least the roughened surface of the metal is heated to a temperature which, in the processing range from room temperature to 100°C, is above the processing temperature of the at least one plastic component.

[0014] Preferably, a scanner with a suitable focal length and beam path is used to generate the macroscopic undercuts of the metal surface using short-pulse laser radiation. The scanner and the metal surface to be roughened can be moved continuously relative to each other at a predetermined speed. The scanner's movement is superimposed on an axis movement of a robot or the axis system or coordinate system of the object being processed, so that the scanner optics guide the laser beam in an endless loop across the metal surface within its working field, creating a uniform roughening (structuring) across the entire metal surface during continuous relative movement.

[0015] Preferably, the temperature to which the roughened surface of the metal is heated is in the range of 100°C below the processing temperature of the at least one plastic component.

[0016] The heating of the roughened metal surface can be carried out to a temperature higher than the glass transition temperature, preferably in the range of the latter for thermoplastics.

[0017] Preferably, the temperature to which at least the roughened metal surface of the metal is heated is selected depending on parameters such as process duration, viscosity of the melt and fineness and depth of the roughening (structuring) of the metal surface.

[0018] In a preferred embodiment of the method according to the invention, the metal can be heated in an injection mold, preferably inductively. Inductive heating of the metal side of the composite material in the injection mold allows for very precise temperature control and ensures uniform heating of the metal side of the composite material, thus guaranteeing maximum process stability.

[0019] However, the heating of the metal side of the composite material can also take place outside the injection mold, e.g., in an oven. This allows for the use of a significantly simpler injection mold in the process according to the invention, provided that the process steps are performed in a temporally immediate sequence. Furthermore, the use of a comparatively inexpensive injection mold is possible when the metal side of the composite material is heated by controlled temperature control using water, oil, or gas in an internal high-pressure (IHU) process.

[0020] The temperature achievable on the metal side of the composite material through variable temperature control depends on the properties of the chosen plastic component. For example, when using thermosets for the plastic component, the heating of at least the roughened metal surface can preferably be achieved to a temperature above the glass transition temperature of the plastic component and below the maximum processing temperature of the plastic component during injection molding of the roughened metal surface. This temperature is selected based on process parameters such as injection molding duration, melt viscosity, and the fineness and depth of the roughening (structuring) of the metal surface. Crucially, the undercuts of the roughened metal surface must be at least partially filled by the plastic component.

[0021] Both thermoplastic molding compounds and post-curing molding compounds such as thermosets, as well as multi-component systems, are used as plastic components. These can be modified in terms of type and composition to meet the specific requirements of the application environment of the plastic-metal hybrid component manufactured according to the invention. A lower viscosity of a polymer component or a corresponding resin system proves advantageous for filling the cavities of the structured metal surface.

[0022] Possible modifications to the composition of the polymer components include the chemical structure of the polymer molecules. Thermoplastic polymers such as polyamides, polyesters, polyacetals, polybutylene terephthalate, and polyolefins like polypropylene or polyethylene, or mixtures thereof, or polyamides such as polyamide 6 or polyamide 6.6, or polyphenylene oxide or polyetherimide are preferred. Semi-crystalline polyamide 66 has proven advantageous due to its combination of high heat resistance and flowability.

[0023] Possible combinations of the composition of the plastic component also include both the area of ​​fillers and reinforcing materials, in particular fiber- and platelet-like reinforcing materials, as well as the area of ​​additional additives, in particular with regard to an adhesion modification of the plastic or at least one plastic component on the structured metal surface.

[0024] In the area of ​​fillers and reinforcing materials, components that reduce the coefficient of linear expansion of the plastic component and decrease stresses in the interface region of the composite material caused by temperature changes are particularly advantageous. Glass fiber, carbon fiber, or aramid fiber are preferably used as fibers to reinforce the at least one plastic component. In this context, polymer-based reinforcement systems such as aramid fibers, which exhibit a negative coefficient of thermal expansion along the fiber orientation, prove to be particularly advantageous.

[0025] In the process according to the invention, plastic components can be molded without reinforcing fibers, with relatively short reinforcing fibers, for example with a fiber length of less than 1 mm, preferably less than 0.4 mm or short glass fibers, before the injection molding process, and / or with relatively long reinforcing fibers. For example, fibers with a length of 1-30 mm can be used before the injection molding process. Thermoplastic, thermoset, and elastomeric plastics can be used, with fiber-reinforced engineering plastics such as polypropylene or polyamide being preferred.

[0026] Filling the cavities of the textured metal surface during injection molding with fiber-reinforced plastic ensures high load-bearing capacity of the composite material. Surprisingly, excellent adhesion of the plastic component, particularly the glass fiber-reinforced plastic component, can be achieved in the macroscopic and / or microscopic undercuts of the roughened metal surface. Using a partially vacuum-sealed injection mold, complete filling of the textured cavities in the metal surface can be achieved.

[0027] When using steel as the metal and highly reinforced thermoplastic as the plastic component, e.g. semi-crystalline polyamide 66, the roughened steel surface is heated to a temperature in the range of 100°C below melt temperature to the melt temperature during processing before the injection molding process with the highly reinforced thermoplastic.

[0028] Preferably, the at least one plastic component is mixed with additives to increase its adhesion to the roughened and heated metal surface before injection molding.

[0029] Preferably, the production of the material composite of the plastic-metal hybrid component is numerically simulated depending on the process parameters, heating at least the roughened surface of the metal to a certain temperature, the process duration of the injection molding, the viscosity of the melt and the fineness and depth of the roughening (structuring) of the metal surface.

[0030] If aluminum is used as the metal in the composite material and, after roughening the aluminum surface, the aluminum component is internally high-pressure formed with the at least one plastic component in a combined internal high-pressure injection molding process, the forming heat of the aluminum can be used to heat the roughened aluminum surface in the injection molding process with the at least one plastic component.

[0031] The plastic-metal hybrid component producible according to the invention is preferably used as a structural component with a relatively high degree of lightweight construction in automotive engineering or in the manufacture of other means of transport or for electronic devices.

[0032] Key advantages of the invention lie in the creation of a highly resilient and robust bond between plastic and metal, which is extremely insensitive to the surface cleanliness of the metal prior to processing. The composite material proves to be extremely stable in temperature cycling tests and corrosion tests.

[0033] By inductively heating the metal side of the composite material in the injection mold, the heating temperature of the metal surface can be controlled very precisely and uniformly, thus ensuring high process stability.

[0034] Furthermore, by heating the metal side of the composite material outside the injection mold, it can be realized in a significantly simpler embodiment, provided that the process steps of the inventive method are carried out in close temporal succession.

[0035] Furthermore, specifically adapted structures with macroscopic roughening depths in the range of 100 µm to 1 mm with stochastically arbitrary microscopic roughness shapes are possible, thus ensuring optimal interlocking of plastic and metal in the subsequent injection molding process.

[0036] In particular, the inventive method ensures that, in order to optimize the bond strength of the plastic-metal hybrid component to be joined, premature freezing of the at least one plastic component is avoided in the injection molding process, and that at least partial filling of the undercuts is achieved with excellent

[0037] Undercutting of at least one plastic component into the macroscopic and / or microscopic undercuts of the roughened metal surface is achieved, and maximum adhesion of the at least one plastic component to the structured metal surface is ensured.

[0038] The inventive method ensures the production of a composite material made of metal and plastic to form a plastic-metal hybrid component, which continues to exhibit excellent durability of the connection even after temperature changes and / or corrosion.

[0039] The invention will now be explained with reference to the figures in the drawings. These include: Fig. 1 a microscopic representation of a structuring of the metal surface of a first metal-polymer composite, Fig. 2 a microscopic representation of a structuring of the metal surface of a second metal-polymer composite, Fig. 3. A SEM image of the structuring of the metal surface. Fig. 4 a schematic representation of a structuring of the metal surface of an aluminum-glass fiber reinforced polymer composite, Fig. 5 a schematic representation of a structuring of the metal surface of a metal-glass fiber reinforced polyamide composite, wherein the unfilled areas are marked, Fig. 6 a schematic representation of a structuring of the metal surface of a steel-glass fiber reinforced polyamide composite, Fig. 7. A photograph of a test specimen of a plastic-aluminium hybrid component after destructive testing. Fig. 8 a schematic representation of the optics of a scanner during its movement, Fig. 9 a schematic representation of the scanner movement in the work area, and Fig. 10 a flow diagram of an embodiment of the method according to the invention, from which the optimization of the bond strength of the plastic-metal hybrid component is shown.

[0040] The invention will now be explained with reference to the figures in the drawings. These include: The Fig. 1 and Fig. Figure 2 shows a microscopic image of laser structuring on the metal surface of a first or second metal-polymer composite to be produced, respectively, with varying spacing and depth of the laser structuring patterns created to prepare the joining surface of the respective metal-polymer composite. The laser structuring is described in the following section: Fig. Figure 3 shows the material being applied over a surface to the metal surface 3 to roughen it, the size of which is determined by the forces to be transmitted in the respective metal-polymer composite to be produced. The laser structuring is carried out using short-pulse laser radiation, whereby - as shown in the Fig. As can be clearly seen in Figures 1 to 3, macroscopic and / or microscopic undercuts are randomly and stochastically introduced into the metal surface to roughen it. During the joining of the metal-polymer composite in an injection molding process, the macroscopic and / or microscopic undercuts are at least partially filled with the polymer component, such that the polymer interlocks with the undercuts, significantly improving the adhesion between the metal surface and the polymer component.

[0041] Out of Fig. Figure 4 shows a CT scan of the joining surface of an aluminum-glass fiber-reinforced polyamide composite, with the aluminum, featuring the laser-structured surface and undercuts, and the glass fiber-reinforced polyamide material, which fills the undercuts, shown at the top. Since the laser structuring of the aluminum surface cannot be completely de-vented during the injection molding process, small unfilled remnants remain (visible as dark areas in the image), which can be avoided by using a partially vacuum-sealed injection mold.

[0042] Fig. Figure 5 shows a detailed image of the joint of a steel-glass fiber-reinforced polyamide composite. The metal is shown in dark gray at the bottom, the polyamide in medium gray at the top, the glass fibers in light gray within the polyamide, and the areas of the metal-glass fiber-reinforced polyamide composite not filled with glass fiber-reinforced polyamide are marked in white. Here, too, macroscopic and / or microscopic undercuts were randomly and stochastically introduced into the metal surface prior to the joining of the metal-glass fiber-reinforced polyamide composite in an injection molding process. This roughening was achieved by short-pulse laser radiation. Short glass fibers with a length of 1-2 mm and / or long glass fibers with lengths up to 30 mm can be used to reinforce the polyamide prior to the injection molding process.Using a partially vacuum-sealed injection mold, it is possible to completely fill the laser structuring of the roughened metal surface with the glass fiber reinforced polyamide, thus ensuring a very high load-bearing capacity of the metal-glass fiber reinforced polyamide composite.

[0043] Using a partially vacuum-sealed injection mold, it is possible to completely fill the laser structuring of the roughened metal surface with the glass fiber reinforced polyamide, thus ensuring a very high load-bearing capacity of the metal-glass fiber reinforced polyamide composite.

[0044] Similarly, it shows Fig. Figure 6 shows a detailed image of the joint of a steel-glass fiber reinforced polyamide composite, with the steel shown below and the glass fiber reinforced polyamide mass above, and the undercuts of the laser-structured steel surface filled by the latter. To fill the undercuts and cavities of the laser-structured steel surface during the injection molding process, it is necessary to prevent premature freezing of the plastic mass, especially when using high-viscosity plastics. Therefore, it is necessary to heat the steel surface, roughened by short-pulse laser radiation, before or during the joining process, e.g., by induction.

[0045] For example, in a combination of steel with highly reinforced polyamide 66, a temperature of approximately 250°C for the steel has proven to be very suitable, although depending on the type of polyamide used, such as high-temperature suitable, crash-resistant, etc., the temperature may be approximately 50°C lower or 30°C higher.

[0046] Fig. Figure 7 shows an image of a plastic-metal hybrid component as a test specimen after a destructive test, where the 5 mm base width of the plastic component is visible on a metal sheet measuring 40 mm x 70 mm. If, for example, an internally high-pressure formed aluminum component is to be joined with a plastic component, the forming heat of the aluminum can be used in an integrated joining process, thus eliminating the need for additional heating of the aluminum before joining.

[0047] In connection with the test specimen, it has been shown that fillers and reinforcing materials of the plastic component used, which can penetrate the cavities of the laser-structured metal surface due to their properties, can contribute to improved force transmission near the interface of the composite.

[0048] To prevent corrosion at the joint of the plastic-metal hybrid component, a frame encompassing the joint can first be injection-molded from elastomeric material when using a two-component injection molding process. The thermoplastic or thermoset component, which creates the load-bearing bond, is then applied directly to the laser-structured metal surface of the joint. Alternatively, the elastomeric frame can be applied around the joint after it has been formed, using a suitable process such as injection molding, to create a seal.

[0049] Out of Fig. Figure 8 shows a schematic representation of the optics of a scanner during its movement, which, with adapted focal length of the scanner optics and beam guidance, is used for the stochastically arbitrary introduction of macroscopic and / or microscopic undercuts into the metal surface for roughening it by means of short pulse laser radiation.

[0050] The mechanical structure of the scanner optics 1 is known as such. According to the inventive method, the scanner 2 is moved continuously relative to the metal surface 3 to be roughened at a predetermined speed (arrow v), while its movement is simultaneously superimposed on an axis movement of a robot (not shown). The scanner optics 1 guides the laser beam 4 in an endless loop over the metal surface in its working field (x, y) 5, thereby generating a uniform stochastic roughening (structuring) over the entire metal surface to be structured during continuous relative movement.

[0051] As from Fig. As can be seen in Figure 8, a laser beam 4 emanating from a laser light cable 6 of the scanner optics 1 is guided via a collimator 7, the laser optics, and a deflecting mirror 8 arranged downstream of it in the beam direction to a galvanometer scanner system comprising an X-axis scanner 9 and a y-axis scanner 10. From there, it is deflected by a planar field lens 11 arranged downstream in the beam path onto the working area of ​​the metal surface to be structured. When the scanner optics 1 are installed on a robot arm, the joining surface to be roughened can be traversed using a distance control system.

[0052] Fig. Figure 9 illustrates that the scanner optics perform a predetermined relative movement to the workpiece surface to be structured, whereby, as shown from Fig. As shown in Figure 9, the scanner optics guide the laser beam in an endless loop across a closed structure on the workpiece surface within its working field (x, y). By superimposing the two movements, targeted stochastic structural shapes of the metal surface to be structured, adapted to the subsequent load direction, can be generated with varying depths. The shape and depth of the generated laser structuring can be defined by changing the guidance (shape) and / or speed of the beam movement and simultaneously adjusting the laser parameters such as power and / or repetition rate. Structuring depths from a few hundred micrometers to 1 mm are possible. Adapting the injection molding process to the properties of the joining partner and the specified load profile is thus possible.

[0053] Fig.Figure 10 illustrates the possibilities for optimizing the bond strength of a composite material made of metal and plastic to form a plastic-metal hybrid component, as produced according to the invention. According to the test specifications of a test station (Block A) of the composite material to be produced, a change in the metal structuring (Block B) as well as a modification of the plastic granules used (Block C) of the respective joining partner, metal or plastic component, is possible by means of a respective so-called external optimization (direction arrow I or II).Furthermore, according to the test specifications of the workpiece assembly to be produced (Block A), after the metal component with laser-structured surface (Block B) is introduced (direction arrow III) into an injection mold (Block D) for heating (Block E) within the latter, and after the plastic granules (Block C) are introduced (direction arrow IV) into the injection mold (Block D) to produce a melt (Block F) of the plastic granules before joining the two joining partners in an injection molding process (Block G), a change in the metal temperature (direction arrow V) or a change in the melt temperature (direction arrow VI) is possible by means of a respective internal optimization, so that the injection molding process (Block G) after input of optimized values ​​from the heating of the metal component (direction arrow VII) orfrom the melt of the plastic component (direction arrow VIII) and the material composite with optimized bond strength is produced, which is taken from the injection mold (block D) and fed back to the test station (block A) (direction arrow IX). List of reference symbols 1 Scanner optics 2 scanners, galvanometer scanner 3. Metal surface to be roughened 4 Laser beam 5 Working area of ​​the scanner optics 6 laser light cables 7 Collimator 8 deflecting mirrors 9 X-axis scanners 10 Y-axis scanners 11 Plan field lens v Arrow for scanner speed Block A Test station of the workpiece assembly to be manufactured Block B: Change in metal structuring Block C: Modification of the plastic granules Block D injection mold Block E Heating Block F Melt Block G Injection Molding Process Arrow I external optimization of the change in metal structuring Arrow II external optimization of the change in the plastic granules Arrow III: Insertion of the metal component with laser-structured surface into the injection mold. Arrow IV: Introduction of the plastic granules into the injection mold Arrow V Change in metal temperature Arrow VI Change in melting temperature Arrow VII internal optimization of the heating of the metal component Arrow VIII internal optimization of the change in melting temperature Arrow IX Feeding the composite material to test station A

Claims

[1] A method for producing a composite material of metal and plastic to form a plastic-metal hybrid component, in which macroscopic undercuts with microscopic undercuts having stochastically random roughness shapes and depths are introduced into the metal surface by means of short-pulse laser radiation to improve the adhesion between the metal surface and at least one plastic component, wherein the shapes and depths of the laser structuring of the metal surface are produced by changing the guidance and / or speed of the laser beam movement and simultaneously adjusting the power and / or repetition rate of the short-pulse laser radiation, and the stochastically random roughness shapes are each at least partially filled with the at least one plastic component in an injection molding process such that the latter is gripped in the macroscopic and / or microscopic undercuts.wherein, following the roughening of the metal surface prior to the injection molding process of the at least one plastic component, at least the roughened surface of the metal is heated to a temperature which, in the processing range from room temperature to 100°C, is above the processing temperature of the at least one plastic component. [2] Method according to claim 1, characterized by , that the temperature to which the roughened surface of the metal is heated is in the range of 100°C below the processing temperature of at least one plastic component. [3] Method according to claim 1 or 2, characterized by that the roughened surface of the metal is heated to a temperature higher than the glass transition temperature, preferably in the range of the latter for thermoplastics. [4] Method according to any one of the preceding claims, characterized by, that the temperature to which at least the roughened metal surfaces of the metal are heated is chosen depending on process parameters such as process duration, viscosity of the melt and fineness and the depth of roughening (structuring) of the metal surfaces. [5] Method according to any one of the preceding claims, characterized by , that a scanner with adapted focal length of scanner optics and beam guidance is used to generate the macroscopic undercuts of the metal surface using short pulse laser radiation. [6] Method according to claim 4, characterized by, that the scanner is moved continuously at a predetermined speed relative to the metal surface to be roughened, and its movement is superimposed with an axis movement of a robot, whereby the scanner optics simultaneously guide the laser beam in an endless loop over the metal surface in its working field, and a uniform roughening (structuring) is endlessly generated on the entire metal surface during continuous relative movement. [7] Method according to any one of the preceding claims, characterized by that the heating of the metal takes place inside the injection mold. [8] Method according to any one of the preceding claims 1-5, characterized by that the heating of the metal takes place outside the injection mold in an oven. [9] Method according to any one of the preceding claims, characterized by that the heating of the metal occurs inductively. [10] Method according to any one of the preceding claims, characterized by that the heating of the metal is achieved through variable temperature control [11] Method according to any one of the preceding claims, characterized by that the heating of the metal is carried out by water, oil or gas in an internal high-pressure forming process. [12] Method according to any one of the preceding claims, characterized by , that thermoplastics are used for at least one plastic component. [13] Method according to claim 11, characterized by , that thermoplastic polymers such as polyamides, polyesters, polyacetals, polybutylene terephthalate and polyolefins such as polypropylene or polyethylene or mixtures thereof or polyamides such as polyamide 6 or polyamide 6.6 or polyphenylene oxide or polyetherimide are chosen as thermoplastics. [14] Method according to any one of claims 1-10, characterized by , that at least one plastic component is made of thermosets. [15] Method according to any one of claims 1-10, characterized by that at least one plastic component uses elastomers or elastomer-like materials [16] Method according to any one of the preceding claims, characterized by that the injection molding process with at least one plastic component takes place under at least partial vacuum. [17] Method according to any one of the preceding claims, characterized by that at least one plastic component is compounded with fillers and reinforcing agents. [18] Method according to claim 15, characterized by , that fillers and reinforcing materials are used which reduce the coefficient of linear expansion of at least one plastic component. [19] Method according to claim 15 or 16, characterized by , that fibers such as glass fibers, carbon fibers, aramid fibers or natural fibers made of flax, hemp or sisal are used to reinforce at least one plastic component. [20] Method according to claim 16 or 17, characterized by that fibers with a fiber length of less than 1 mm or less than 0.4 mm or short glass fibers are used. [21] Method according to claim 16 or 17, characterized by that fibers with a fiber length in the range of 1 mm to 30 mm or long glass fibers are used. [22] Method according to claim 15 or 16, characterized by , that polymer-based reinforcement systems such as aramid fibers are used as reinforcing materials, which have a negative coefficient of thermal expansion along the fiber orientation. [23] Method according to claims 11 to 21, characterized by, that when using steel, aluminium or other metals and highly reinforced thermoplastic as a plastic component, the roughened steel surface is heated to a temperature in the range of 100°C below the melt temperature in processing before the injection molding process with the highly reinforced thermoplastic. [24] Method according to any one of the preceding claims, characterized by that at least one plastic component is compounded with additives to increase its adhesion to the roughened and heated metal surface. [25] Method according to any one of claims 1 to 21, characterized by, that an aluminum workpiece is used as the metal of the material composite, wherein, after roughening the aluminum surface, the aluminum workpiece is internally high-pressure formed into an aluminum component before injection molding with the at least one plastic component, and the resulting forming heat of the aluminum is used to heat the roughened aluminum surface for the injection molding process with the at least one plastic component, which takes place directly in the same tool. [26] Method according to any one of the preceding claims, characterized by , that the production of the material composite of the plastic-metal hybrid component is numerically simulated depending on the process parameters: heating of at least the roughened surface of the metal to a temperature, process duration of the injection molding, temperature-dependent viscosity of the melt and fineness and depth of the roughening (structuring) of the metal surface. [27] Use of the plastic-metal hybrid component produced according to the method of claims 1-26 as a structural component in automotive engineering or in the manufacture of other means of transport and for electronic devices.

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