Method for directly bonding metals to polymer / polymer composites using functionally active insert layers

Abstract

A method of joining a metal component and a polymer / polymer composite component, the method comprising: providing a metal component; providing a polymer or polymer composite component; inserting an insertion layer between the metal component and the polymer or polymer composite component; and applying heat to the metal component to reach a temperature higher than the melting temperature of the polymer or polymer composite component and the insert layer and lower than the degradation temperature of the polymer or polymer composite component and the insert layer, and simultaneously applying pressure to the combination of the metal component, the polymer or polymer composite component, and the insert layer to combine the metal component and the polymer or polymer composite component into a bonded assembly having a chemical bond therebetween.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Patent Application No. 18 / 223,829, filed on July 19, 2023, which claims the benefit of U.S. Provisional Application No. 63 / 391,030, filed on July 21, 2022. The entire disclosure of the above application is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to joining materials and, more particularly, to methods of directly joining metals to polymers and / or polymer composites using functionally active insert layers. Summary of the invention

[0004] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0005] According to the principles of the present teachings, methods are provided for directly bonding a polymer or polymer composite to a metal using an intercalation layer of a functionally active polymer under various heating and pressure application mechanisms on the metal side without requiring any kind of surface or material pretreatment or medication on the metal or polymer / polymer composite side. In general, polyolefin polymers are difficult to bond to any known metal, primarily due to its non-polar nature. Specifically, these methods successfully demonstrate the use of a functionally active intercalation layer to bond a polyolefin polymer or polyolefin polymer composite to bare metal and e-coated metal with significant bond strength.

[0006] Further areas of applicability will become apparent from the description provided herein.The description and specific examples of the present invention are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0008] Figure 1 is a schematic diagram of the present teachings, showing the bonding of a metal or metal alloy to a polymer and / or polymer composite, according to some embodiments.

[0009] Figure 2is a schematic diagram of a system for joining a metal or metal alloy to a polymer and / or polymer composite according to the present teachings, according to some embodiments.

[0010] Figure 3 is a schematic diagram of a system of the present teachings showing the bonding of coated / uncoated ferrous / non-ferrous metals to a polymer composite, according to some embodiments.

[0011] Figure 4 is a schematic diagram of a system of the present teachings showing bonding of an electrophoretically coated metal to a polymer and / or polymer composite, according to some embodiments.

[0012] Figure 5 is a schematic diagram of a system of the present teachings showing the bonding of uncoated metal to a polymer, according to some embodiments.

[0013] Figure 6 is a schematic diagram of a system of the present teachings showing the bonding of an uncoated metal to a polymer composite, according to some embodiments.

[0014] Figure 7 is a schematic diagram of a system of the present teachings showing bonding of a coated metal to a polymer and / or polymer composite, according to some embodiments.

[0015] Figure 8 is a schematic diagram of a system of the present teachings showing the joining of metal to a polymer and / or polymer composite during an extrusion process, according to some embodiments.

[0016] Fig. 9 is a schematic diagram of a system of the present teachings, showing the joining of metal to a polymer and / or polymer composite during an injection molding process, according to some embodiments.

[0017] Fig.10 is a schematic diagram of a system of the present teachings, showing the joining of metal to a polymer and / or polymer composite during an injection compression molding process, according to some embodiments.

[0018] Fig.11 is a schematic diagram of a system of the present teachings, according to some embodiments, illustrating the joining of metal to polymer and / or polymer composite during an additive (3D printing) molding process.

[0019] Fig.12 is a schematic diagram of a system of the present teachings, illustrating the thermal flow process and the melting and flow mechanisms, according to some embodiments.

[0020] Fig.13 Experimental demonstrations related to uncoated metal and polymer composites according to the present teachings are shown.

[0021] Fig.14 Experimental demonstrations related to uncoated metal and polymer composites according to the present teachings are shown.

[0022] Fig.15 Experimental demonstrations related to coated metal and polymer composites according to the present teachings are presented.

[0023] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0024] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0025] Example embodiments are provided so that the disclosure will be thorough and the scope will be fully conveyed to those skilled in the art. Many specific details, such as examples of specific components, devices and methods, are set forth to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be used, and that the example embodiments may be embodied in many different forms, and neither should be construed as limiting the scope of the present disclosure. In some example embodiments, known processes, known device structures and known techniques are not described in detail.

[0026] The terms used herein are only used for the purpose of describing specific example embodiments and are not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms "a / an" and "the" may be intended to include plural forms. The terms "comprises", "comprising", "including" and "having" are inclusive, and therefore specifically refer to the presence of the features, integers, steps, operations, elements and / or components, but do not exclude the presence or increase of one or more other features, integers, steps, operations, elements, components and / or combinations thereof. Unless explicitly identified as an execution order, the method steps, processes and operations described herein should not be interpreted as having to be performed in the specific order discussed or illustrated. It should also be understood that additional or optional steps may be adopted.

[0027] When an element or layer is referred to as being "on another element or layer," "engaged to another element or layer," "connected to another element or layer," or "coupled to another element or layer," the element or layer may be directly on, directly engaged to, connected to, or coupled to another element or layer, or there may be intervening elements or layers. Conversely, when an element is referred to as being "directly on another element or layer," "directly engaged to another element or layer," "directly connected to another element or layer," or "directly coupled to another element or layer," there may be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0028] Although the terms first, second, third, etc. can be used to describe different elements, components, regions, layers and / or sections in this article, unless otherwise specified, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer and / or section from another region, layer and / or section. When used in this article, unless the context clearly indicates, terms such as "first", "second" and other numerical items do not imply order or sequence. Therefore, without departing from the teaching of the example embodiment, the first element, the first component, the first area, the first layer or the first section discussed below can be referred to as the second element, the second component, the second area, the second layer or the second section.

[0029] For ease of description, spatially relative terms such as "inside," "outside," "beneath," "below," "lower," "above," and "upper" may be used herein to describe the relationship of one element or feature to another element or elements or another feature or features, as shown in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the figure is turned over, an element described as being "below" or "beneath" other elements or features will subsequently be oriented to be "above" the other elements or features. Thus, the example term "below" is able to encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or oriented in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

[0030] According to the principles of the present teachings, there is provided a method and product made by the proposed process having advantageous steps and configurations related to the bonding of uncoated and / or uncoated metals to polymers and / or polymer composites using functionally active thin film intercalation layers. Figure 1 In some embodiments schematically illustrated in the drawings, the present teachings provide a joining method 10 in which a metal part 12 is joined to a polymer and / or polymer composite part 14 via an insert film 16 using applied heat 100 and pressure 102 to produce a joint 18 formed between the metal part 12 and the polymer / polymer composite part 14 using the insert film 16.

[0031] In some embodiments, the metal component 12 can include coated and / or uncoated metal (see Figures 5 to 7 ). That is, in some embodiments, the metal component 12 can include surface treatment and / or modification, such as but not limited to any form, for example physical, chemical, thermal, laser, optical, electrochemical, electromagnetic and / or a combination thereof. It should be understood that the surface of the metal component 12 can be cleaned using any chemical solvent. For example, at least the bonding surface can be degreased using a non-caustic chemical without changing the surface roughness of the bonding surface of the metal component. In some embodiments, the non-corrosive chemical is ethanol, acetone, or any surface degreasing non-caustic agent. However, it should also be understood that in some embodiments, surface cleaning of the metal component 12 may not be necessary or desirable. It should also be understood that the coating (see at least Figure 7 ) can include, but are not limited to, any type of electrophoretic coating (e-coating), galvanic coating, corrosion resistant (or atmospheric protection) coating, or any such coating, including compatible or incompatible adhesive coatings. In some embodiments, the metal surface has a roughness of less than Ra 0.76 micrometers (μm).

[0032] In some embodiments, the metal component 12 can include any type (see Figures 5 to 7 ), such as but not limited to pure metal, ferrous metal or non-ferrous metal, any kind of metal alloy, treated (including but not limited to any kind of physical, chemical or metallurgical treatment) or untreated. In addition, in some embodiments, the metal component 12 can be configured in any shape, size or form and used for any type of application.

[0033] In some embodiments, the polymer and / or polymer composite part 14 can have any kind of resin (particularly, but not limited to, polyolefin thermoplastics) and can be from any class of polymers, such as, but not limited to, natural and / or synthetic polymers. In embodiments having a polymer composite part 14, the fibers in the polymer composite can be in any form, such as, but not limited to, any kind and / or form, glass fibers, carbon fibers, aramid fibers, short fibers, long fibers, continuous fibers, spherical fibers, and any other fibers or combinations thereof. In some embodiments, the polymer and / or polymer composite part 14 can be in any form, such as sheets, blocks, tubes, pipes, or any other geometric shapes of any size or thickness. In some embodiments, the polymer and / or polymer composite part 14 can be in the form of an elastomer (natural rubber, or synthetic rubber, or front / rear form of a rubber material), such as, but not limited to, latex, natural rubber, EPDM (ethylene propylene diene monomer, ethylene-propylene-butadiene monomer (EPDM)) or a combination / mix of two or more polymers or any such form. In some embodiments, the polymer and / or polymer composite component 14 can include a polyolefin polymer, such as a polyolefin polymer produced from very simple olefin monomers without any functional groups in the chemical structure. In some embodiments, the polymer and / or polymer composite component 14 can include thermoplastic polyolefins, such as but not limited to polypropylene [PP (Polypropyelene, including homopolymers and / or copolymers)], low-density polyethylene (LDPE), linear low-density polyethylene (LDPE), very-low-density polyethylene (VLDPE), ultra-low-density polyethylene (ULDPE), medium-density polyethylene (MDPE), polymethylpentene (PMP), polybutene-1 (PB-1), ethylene-octene copolymer, stereo block PP, olefin block copolymer, propylene-butane copolymer, polyolefin elastomer, polyisobutylene (PIB), poly (α-olefin), ethylene propylene rubber (ethylene propylene rubber, etc. rubber, EPR) and ethylene-propylene-butadiene monomer (M grade) rubber (EPDM rubber, ethylene propylene diene monomer rubber) and their compositions.

[0034] In some embodiments, the insert film layer 16 can include a film or layer that can be any type of functional polymer or polar polymer (i.e., functionally active), such as but not limited to nylon (or polyamide PA, PA6, PA66, PA12, etc.), polyester (PET), polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polyimide (PI), polyaryletherketone (PAEK), polyetheretherketone (PEEK), syndiotactic polystyrene (SPS), polyphthalamide (PPA), polybutylene terephthalate (PBT), polyoxymethylene (POM), polyamide-imide (PAI), polymethyl methacrylate (PMA ...methyl methacrylate (PMA), polyim methyl methacrylate, PMMA), polyphenylsulfone (polyphenylsulfone, PPSU, PPSF), vitrimer (covalent adaptable network, covalent adaptable network, CAN), etc. or a combination thereof. In some embodiments, the inserted film layer 16 can be a functionally active inserted layer of a material different from the polymer or polymer composite component 14. In some embodiments, the thickness of the inserted film layer 16 can be a few nanometers, a few microns or a few millimeters. In some embodiments, the inserted film layer 16 can be in any form, such as but not limited to a film (solid or flexible) with a thickness of millimeters or microns, a powder form, a spray form (aerosol form), nanorods, nanoparticles, nanofilms, etc. and combinations thereof. However, it should be understood that the inserted film layer 16 is not expected to be in the form of any type of adhesive. In some embodiments, the inserted film layer 16 can be in the form of a fiber-filled prepreg and / or wherein the base polymer material is a thermoplastic polymer and the fibers can be in any form (continuous, small, long, chopped, spherical, etc.) or type (glass, carbon, aramid, natural, etc.) in the prepreg. In some embodiments, the insert membrane layer 16 can be made of fiber-filled or unfilled glass-like polymer reinforcement material. In some embodiments, the reinforcement material is selected from the group consisting of natural fibers, glass fibers, carbon fibers, glass or silica particles.In some embodiments, the intervening layer material can be mixed with the base polymer / polymer composite in situ or ex situ to form a mixture.

[0035] According to the present teachings, a method is provided in which an insert film layer 16 made of a polymer and / or a polymer composite is inserted between a metal part 12 and a polymer part 14. The method also includes heating the metal part 12 using a heating source or system 102, while applying and maintaining the assembly (i.e., the metal part 12, the polymer part 14, and the insert film layer 16) under sufficient pressure by actuating a forging force system 106 to maintain close contact between the metal part 12, the polymer / polymer composite part 14, and the insert film layer 16. That is, in some embodiments, the metal part 12, the polymer part 14, and the insert film layer 16 are joined by maintaining the metal part 12, the polymer part 14, and the insert film layer 16 under the pressure and sufficiently heating the metal side (i.e., the metal part 12) to reach the melting point of the polymer part 14 and the insert film layer 16 (but not too high to avoid the polymer flash point and the metal melting temperature). The molten polymers of the polymer part 14 and the insert film layer 16 are physically mixed (see Fig.12 and Fig.14 ) and / or can be mixed together by chemical reactions between polymer molecules. In the case of a polymer composite, the melted polymer forms an intermixed polymer composite at the interface 18 (see Fig.12 and Fig.14 ). In general, a polymer melt pool of sufficient volume is produced to chemically react / atomically react and bond closely to the metal surface of the metal component 12 (see Figure 12-15 ).

[0036] In some embodiments, the heating source or system 102 can include any heating source, such as external, internal, direct, indirect, derived, or any combination thereof. That is, the heating source 102 can be applied from the outside of the metal part 12 in physical contact or away from it; from the inside of the metal part 12 using a polymer melt pool or by any other combination. The heating source or system 102 can include laser heating, friction heating (such as but not limited to friction points (see Figures 5 to 7 ), friction lap, friction stirring), melting (such as but not limited to 3D printers) (see Fig.11 ), hot water treatment heating, ultrasonic heating, injection molding heating (see Figures 9 and 10 ), induction heating, thermal heating, resistance heating, laser heating, high energy beam heating, high speed plastic deformation heating, extrusion heating (see Figure 8 ), extrusion molding, plastic molding, etc. and their combinations.

[0037] In some embodiments, the forging force system 106 can provide sufficient pressure to maintain intimate contact between the metal component 12, the polymer component 14, and the insert film layer 16. The forging force system 106 can include any type of system, such as but not limited to hydraulic, mechanical, electromechanical, electronic servo actuators, etc. and combinations thereof. In some embodiments, the heating source 102 and the forging force system 106 can be an integrated system. In some embodiments, the compressive force exerted by the forging force system 106 can be applied perpendicular to the joint interface. Back support can be provided to resist such compressive forces.

[0038] Therefore, it should be understood that the method of the present teaching provides direct joining of metals and difficult-to-weld polymers / polymer composites to manufacture and / or provide cost-effective metal-polymer hybrid structures for structural lightweight applications. Since no surface treatment of any type is required on the metal or composite side, significant cost savings are achieved. Due to simplified processing, the present method also provides the ability to be mass-produced.

[0039] Furthermore, the present teachings enable joining by chemical bonding to the metal rather than by mechanical interlocking (anchoring), and provide the ability to join coated / uncoated metals to polyolefin thermoplastic polymers / polymer composites. The present teachings do not require any type of special surface / bulk treatment on either the metal or polymer / polymer composite side, and provide the ability to join coated (corrosion protection layer, such as epoxy resin applied by electrophoresis, etc.) (see Fig.15 ) or the ability of uncoated metal to bond to polymer / polymer composites.

[0040] For the purpose of illustration and description, a description of the above-mentioned embodiments is provided. It is not intended to be exhaustive, or to limit the present disclosure. The individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable, and can be used for a selected embodiment, even if not specifically shown or described. The same situation can also be different in many ways. Such changes should not be considered as departures from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

Claims

1. A method for joining a metal component and a polymer / polymer composite component, the method comprising: providing the metal component; Providing the polymer or polymer composite component; inserting an interposer between the metal component and the polymer or polymer composite component; as well as Heat is applied to the metal part to reach a temperature higher than the melting temperature of the polymer or polymer composite part and the inserted layer and lower than the degradation temperature of the polymer or polymer composite part and the inserted layer, and pressure is simultaneously applied to the combination of the metal part, the polymer or polymer composite part and the inserted layer so that the metal part and the polymer or polymer composite part are combined into a joined assembly having a chemical bond therebetween.

2. The method according to claim 1, wherein: The method further comprises: The joining surfaces of the metal parts are degreased using a non-corrosive chemical without changing the surface roughness of the joining surfaces of the metal parts.

3. The method according to claim 2, wherein: The non-corrosive chemical is ethanol or acetone.

4. The method according to claim 2, wherein: The non-corrosive chemical is a surface degreasing non-corrosive agent.

5. The method according to claim 2, wherein: The metal component has a surface roughness of less than Ra 0.76 micrometers (μm).

6. The method according to claim 1, wherein: The insertion layer is a functional active polymer material layer.

7. The method according to claim 1, wherein: The insertion layer is a composite material layer having a functional active polymer as its base material matrix.

8. The method according to claim 1, wherein: The insert layer includes reinforcement.

9. The method according to claim 8, wherein: The reinforcement is selected from the group consisting of natural fibers or particles, glass fibers or particles, carbon fibers or particles, glass or silica particles.

10. The method according to claim 1, wherein: The intervening layer has a thickness in the range of 1 nanometer (nm) or more and 6 millimeters (mm) or less at the junction between the surface of the metal component and the surface of the polymer or polymer composite layer / component.

11. The method according to claim 1, wherein: The step of providing the polymer or polymer composite part comprises injection molding, wherein a molten polymer or polymer composite is placed over the metal part and the interposer is placed therebetween.

12. The method according to claim 1, wherein: The step of providing the polymer or polymer composite part comprises extrusion, wherein a molten polymer or polymer composite is placed over the metal part and the intervening layer is placed therebetween.

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