Method and system for joining workpieces

Abstract

A method (100) for joining several workpieces (10, 12), the method (100) comprising: Application (102) of adhesive material (14) to a first workpiece (10); Bringing (104) a second workpiece (12) into contact with the adhesive material (14) so ​​that the adhesive material (14) is located between the first workpiece (10) and the second workpiece (12); Contacting (106) of the first workpiece (10) with a first electrode (36) prior to generating (106) a resistance heating; Contacting (106) the second workpiece (12) with a second electrode (40) before generating (106) the resistance heating; Generating (106) resistance heating in the first workpiece (10) and the second workpiece (12) under initial processing conditions to partially cure the adhesive (14) and to join the first workpiece (10) and the second workpiece (14) together to form a partially cured workpiece assembly (44) bonded with adhesive (14); and Exposure (108) of the partially cured workpiece assembly (44) bonded with the adhesive (14) to heat under second processing conditions in order to substantially cure the adhesive (14); wherein the adhesive (14) is a thermosetting adhesive system containing polymers, polymer precursors and / or reactive components, and is in the form of a liquid or paste which cross-links or otherwise hardens depending on temperature and time; wherein the first processing conditions comprise an electric current between the first electrode (36) and the second electrode (40) of 1.5 kA to 2.5 kA, which is generated for a time of 1.5 seconds to 2.5 seconds and is effective to generate a temperature of about 200°C to about 375°C in the first workpiece (10) and the second workpiece (12); wherein the first processing conditions involve applying a force of about 3 kN to about 5 kN through the first electrode (36) and the second electrode (40) to the first workpiece (10) and the second workpiece (12); and where the second processing conditions include a temperature of approximately 150°C to approximately 200°C and a duration of approximately 15 minutes to approximately 25 minutes.

Description

Technical field

[0001] The present disclosure relates generally to joining technologies and in particular to methods and systems for joining multiple workpieces using adhesive material. introduction

[0002] Spot welding is a common and successful method for joining steel workpieces. Its success was primarily due to the fact that the materials being joined were either identical or very similar. In recent years, newer, more advanced high-strength steels have been developed, possessing many desirable properties. However, when the materials to be joined are not identical or similar (e.g., a high-strength steel workpiece being joined to a workpiece made of structural steel or an aluminum alloy), spot welding the two materials presents a greater challenge. For example, when spot welding metal workpieces that differ significantly, insufficient penetration often occurs in at least one of the metal parts.If the resistances of the individual metal parts differ significantly, the weld may be inadequate and the weld joint may easily break apart. One solution is to mechanically join the two dissimilar materials, for example, with self-piercing rivets. However, if one of the workpieces is made of high-strength steel, using self-piercing rivets to join the two workpieces is sometimes impractical, as the high-strength steel has a relatively high hardness, and the rivets may have difficulty penetrating the much harder, high-strength steel workpiece.

[0003] EP 3 670 564 B1 describes a method for bonding parts, comprising the following steps: (a) providing a two-component adhesive composition precursor, comprising part (A) comprising at least one first dye and at least one epoxy hardener; part (B) comprising at least one second dye, different from the first dye, and at least one epoxy resin; (b) mixing part (A) and part (B) of the two-component adhesive composition precursor to obtain an adhesive composition; (c) applying the adhesive composition to a first part; (d) applying a second part to the adhesive composition applied to the first part; (e) carrying out a first curing step at a first temperature, whereby the adhesive composition undergoes a first color change;Performing a second curing step at a second temperature higher than the first temperature, thereby fully curing the adhesive composition to obtain a structural bond between the first and second parts, with the adhesive composition undergoing a second color change.

[0004] DE 10 2022 124 345 A1 describes methods for resistance welding, resistance-welded assemblies, and vehicles with resistance-welded assemblies. An exemplary resistance welding process involves compressing a stack of workpieces with an interface material between a first and a second workpiece to reduce the thickness of some of the interface material. After the workpiece stack is compressed, the first welding electrode contacts the first workpiece in an operating contact area between the first welding electrode and the first workpiece that is larger than an initial contact area.The process also includes passing an electric current between the welding electrodes to form a molten weld pool in the workpieces, and stopping the passing of the electric current between the welding electrodes so that the molten weld pool can solidify into a weld blob that forms all or part of a weld joint between the workpieces. Description of the invention

[0005] The invention is defined by the claims.

[0006] According to a first aspect of the invention, a method for joining several workpieces is provided. The method comprises applying an adhesive material to a first workpiece. The method further comprises bringing a second workpiece into contact with the adhesive material, such that the adhesive material is positioned between the first and the second workpiece. The method further comprises contacting the first workpiece with a first electrode before generating resistance heating, and contacting the second workpiece with a second electrode before generating resistance heating. The method further comprises generating resistance heating in the first workpiece and the second workpiece under first processing conditions to partially cure the adhesive material and to join the first and second workpieces together to form a partially cured, adhesive-bonded workpiece assembly.The process further comprises subjecting the partially cured, adhesive-bonded workpiece assembly to heat treatment under second processing conditions to substantially cure the adhesive. The adhesive is a thermosetting adhesive system containing polymers, polymer precursors, and / or reactive components, and is in the form of a liquid or paste that cross-links or otherwise cures depending on temperature and time. The first processing conditions include an electric current of 1.5 kA to 2.5 kA between the first and second electrodes, generated for a time of 1.5 to 2.5 seconds, which is effective in generating a temperature of approximately 200°C to approximately 375°C in the first and second workpieces.The first processing conditions further include applying a force of approximately 3 kN to approximately 5 kN through the first and second electrodes to the first and second workpieces. The second processing conditions include a temperature of approximately 150°C to approximately 200°C and a duration of approximately 15 minutes to approximately 25 minutes.

[0007] In some embodiments, both the first and second workpieces contain metal.

[0008] In some embodiments, the first workpiece comprises either a steel or an aluminum alloy, and the second workpiece comprises the other steel or aluminum alloy.

[0009] In some embodiments, the application includes the application of the adhesive, which is selected from a polyurethane adhesive system, an epoxy adhesive system, and an acrylic adhesive system.

[0010] In some embodiments, generating resistance heating includes generating resistance heating in the first and second workpieces under the first processing conditions, in which the first and second electrodes exert a force on the first and second workpieces to squeeze the adhesive material between the first and second workpieces to a thickness of about 100 micrometers (µm) to about 4000 µm.

[0011] According to a further aspect of the invention, a system for joining multiple workpieces is provided. The system comprises a dispenser with which adhesive material can be applied to a first workpiece, wherein the adhesive material is a thermosetting adhesive system containing polymers, polymer precursors, and / or reactive components, and is in the form of a liquid or paste that cross-links or otherwise cures depending on temperature and time. The system further comprises a holder that supports the first workpiece while a second workpiece is brought into contact with the adhesive material, such that the adhesive material is located between the first and the second workpiece. The system further comprises a first electrode that can be operated to contact the first workpiece. The system further comprises a second electrode that can be operated to contact the second workpiece.The first and second electrodes work together to generate resistance heating in the first and second workpieces under first processing conditions to partially cure the adhesive and bond the first and second workpieces together to form a partially cured, adhesive-bonded workpiece assembly. The system further includes a heating arrangement that can be operated to generate heat to be applied to the partially cured, adhesive-bonded workpiece assembly under second processing conditions to substantially cure the adhesive.The first processing conditions include an electric current of 1.5 kA to 2.5 kA between the first and second electrodes, generated for a duration of 1.5 to 2.5 seconds, effective in generating a temperature of approximately 200°C to 375°C in the first and second workpieces. The first processing conditions further include the application of a force of approximately 3 kN to 5 kN by the first and second electrodes to the first and second workpieces. The second processing conditions include a temperature of approximately 150°C to 200°C and a duration of approximately 15 to 25 minutes.

[0012] In some embodiments, the first and second electrodes each have a corresponding longitudinal axis. The first and second electrodes each have a corresponding electrode surface that comes into contact with a corresponding first or second workpiece. The corresponding electrode surface has a maximum area perpendicular to the corresponding longitudinal axis of approximately 8 millimeters (mm) to approximately 40 mm. The first and second electrodes also each comprise a corresponding electrode body that carries the corresponding electrode surface. The corresponding electrode body has a maximum body dimension perpendicular to the corresponding longitudinal axis of approximately 8 mm to approximately 13 mm.

[0013] In some embodiments, the first electrode and the second electrode each comprise a corresponding electrode surface that comes into contact with a corresponding workpiece of the first and second workpieces. The corresponding electrode surface has a shape selected from a circular shape, an oval shape, a polygonal shape, a curved shape, and combinations thereof.

[0014] In some embodiments, the heating device is an oven.

[0015] The above features and advantages, as well as other features and advantages of the present disclosure, are readily apparent from the following detailed description of the best ways of carrying out the disclosure in conjunction with the accompanying drawings. Brief description of the drawings

[0016] The accompanying drawings, which are part of this description, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0017] The Fig. Figures 1-7 show a method and a system for joining multiple workpieces according to one or more embodiments of the disclosure. Fig. Figure 1 shows in cross-section a first workpiece in an early stage of the joining technology according to one or more embodiments of the disclosure; Fig. Figure 2 shows in cross-section a first and a second workpiece during a further advanced joining manufacturing stage according to one or more embodiments of the disclosure; Fig. Figure 3 shows a cross-sectional view of a first and a second workpiece during a further advanced joining manufacturing stage according to one or more embodiments of the disclosure; Fig. 4A is a graphical representation of the nodal temperatures generated by resistance heating at various locations within a stack containing the first and second workpieces during a manufacturing stage of interfacing according to one or more embodiments of the disclosure; Fig. Figure 4B shows a cross-section of the stack containing the first and second workpieces, corresponding to the graphical representation of the node temperatures in Fig. 4A in accordance with one or more embodiments of the disclosure; Fig. 5 is a graphical representation of the processing conditions that are applied to the stack during the process. Fig. The manufacturing stage of intermediate joining shown in 4A-4B is applied in accordance with one or more embodiments of the disclosure; Fig. Figure 6 shows a cross-sectional view of a first and a second workpiece during a further advanced joining manufacturing stage according to one or more embodiments of the disclosure; and Fig. Figure 7 is a flowchart of a method for joining multiple workpieces and a graphical representation of the percentage curing rate (%) of the adhesive material used to join the workpieces by means of the method according to one or more embodiments of the disclosure. Detailed description

[0018] As required, detailed embodiments of the present disclosure are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the disclosure, which can be embodied in various and alternative forms. The illustrations are not necessarily to scale; some features may be exaggerated or reduced in size to show details of certain components. Therefore, specific structural and functional details disclosed herein are not to be understood as limiting, but merely as a representative basis to show the person skilled in the art how to apply the present disclosure in various ways.

[0019] Unless explicitly stated in the context, the term "approximately" here means within a normal tolerance range, e.g., within two standard deviations of the mean. "Approximately" can be understood as within 10%, 5%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. "Approximately" can also be understood as stating the exact value. Unless otherwise indicated in the context, the numerical values ​​given here are modified by the term "approximately."

[0020] The present disclosure relates to methods and systems for joining multiple workpieces. According to one or more embodiments of the disclosure, an adhesive is applied to a first workpiece, for example, via a dispenser connected to a fluid source of the adhesive. In some embodiments, the adhesive is a thermosetting adhesive system containing polymers, polymer precursors, and / or reactive components, and is in the form of a liquid or paste that cross-links or otherwise hardens, for example, when exposed to elevated temperatures for a certain period of time to form a solid mass that bonds to the adjacent surface(s) of the workpiece(s) in contact with the adhesive.

[0021] According to one or more embodiments, the first workpiece is held in a holder either before and during the application of the adhesive to the first workpiece or after the application of the adhesive. A second workpiece touches or is brought into contact with the adhesive, so that the adhesive is located between and in contact with the first and second workpieces. In some embodiments, while the first workpiece is held by the device, the first and second workpieces are positioned and / or arranged relative to each other in accordance with a predetermined geometry.

[0022] A first electrode touches or is brought into contact with the first workpiece, and a second electrode touches or is brought into contact with the second workpiece. The electric current supplied by the first and second electrodes flows through the first and second workpieces to generate resistance heating under initial processing conditions. The term "resistance heating" as used here means that when an electric current passes through the conductive material (e.g., metal, electrically conductive composite, etc.), heat is generated as a function of the loss due to the specific resistance of the conductive material.The heat generated by resistance heating is conducted to the adjacent adhesive material or transferred in some other way, causing the adhesive material to partially cure and the first and second workpieces to bond together, forming a partially cured, adhesive-bonded workpiece assembly. In some embodiments, the first and second workpieces consist at least partially of metal, which may be of the same or dissimilar metals with corresponding similar or dissimilar resistance values. Advantageously, in one or more embodiments of the disclosure, the areas of the first and second workpieces near the first and second electrodes are heated rapidly, causing the adjacent adhesive material to begin reacting rapidly and to cure to a partially cured state in a relatively short time.This causes the adhesive to harden and bond the first and second workpieces sufficiently to maintain the spatial relationship between them without necessarily requiring support from the fixture.

[0023] The partially cured workpiece assembly bonded with the adhesive is removed from the device for subsequent processing. In the further processing step, the partially cured workpiece assembly bonded with the adhesive is subjected to heat under second processing conditions to substantially cure the adhesive. In some embodiments, the downstream processing includes a pretreatment process for applying an electrostatic coating (E-coating) and / or a decorative lacquer to the workpiece assembly, wherein in both cases the workpiece assembly is transferred to an oven that generates heat to cure the applied E-coating and / or decorative lacquer.Advantageously, in one or more embodiments of the present disclosure, the partially cured workpiece assembly bonded with adhesive is exposed to the heat generated as part of one or more downstream processes for curing the electrocoating and / or decorative paint, and at the same time the adhesive bonding the workpiece assembly is substantially fully cured without the need for a separate heating stage or station to complete the curing of the adhesive and without this having a negative impact on the overall manufacturing cycle time.

[0024] Fig. Figure 1 shows a cross-section of a workpiece 10 during an early joining phase according to one or more embodiments of the disclosure. Fig. Figure 7 is a flowchart of a method 100 for joining several workpieces 10 and 12 and a graphical representation of the percentage curing fraction (%) of the adhesive material 14 used to join the workpieces 10 and 12 according to the method 100 in accordance with one or more embodiments of the disclosure.

[0025] The workpiece 10 can consist of one or more workpiece sections 16 and 18, which are joined together, for example, by welding, mechanical fastening, or similar means. In some embodiments, the workpiece 10 comprises two or more workpiece sections 16 and 18 formed from conductive materials, e.g., metal, which may be the same metal or different metals. In some examples, the workpiece sections 16 and 18 are formed from an advanced high-strength steel alloy (e.g., workpiece section 18 is formed from a high-strength steel alloy, e.g., a dual-phase (DP), ultra-high-strength 980 MPa steel alloy (DP980HDG), and workpiece section 16 is formed from another high-strength steel alloy, e.g., a retained austenite (RA), ultra-high-strength 1180 MPa steel alloy (RA 1180), which are welded together).In some embodiments, the workpiece 10 is arranged and held on a support 20.

[0026] Method 100 comprises applying adhesive 14 (box 102) from a dispenser 24 to an outer surface 22 of the workpiece 10. The dispenser 24 comprises a nozzle 26 which is in fluid communication with an adhesive source 28. The adhesive source 28 contains the adhesive 14 in liquid or paste form (e.g., in an uncured state). As shown in Fig. As shown in Figure 7, in some embodiments the adhesive material has a degree of curing of approximately 0% to approximately 15% in the uncured state, for example, of approximately 0% to approximately 10%. With further reference to the Fig. 1 and Fig. 7. The adhesive 14 is conveyed from the adhesive source 28, e.g., via a pump or similar device, through the dispenser 24 and emerges from the nozzle 26 onto the outer surface 22 of the workpiece 10. In some embodiments, the adhesive 14 forms a bead 30 that is applied along a path to the outer surface 22 of the workpiece 10.

[0027] In one or more embodiments, the adhesive 14 is a thermosetting adhesive system containing polymers, polymer precursors and / or reactive components and other additives, and is in the form of a liquid or paste that cross-links or otherwise cures, for example, depending on temperature and time. Non-limiting examples of the adhesive 14 include one- or two-component adhesive systems, such as one- or two-component polyurethane adhesive systems, one- or two-component epoxy adhesive systems, one- or two-component acrylic adhesive systems, or the like.In a non-restrictive example, the adhesive 14 is a one-component, tough epoxy resin system that cures depending on temperature and time, for example, becoming substantially fully cured when exposed to a temperature of about 150°C to about 200°C for a time of about 15 minutes to about 25 minutes, while having a shelf life of about 6 months at a storage temperature of about 5°C to about 25°C (e.g., remaining substantially uncured).

[0028] With reference to the Fig. 2 and Fig. In section 7, the process 100 is continued by bringing the outer surface 32 of the workpiece 12 (box 104) into contact with the adhesive material 14 (e.g., the substantially uncured adhesive bead 30) so that the adhesive material 14 is located between the workpieces 10 and 12. As shown, the holder 20 supports the workpiece 10 while the workpiece 12 comes into contact with the adhesive material 14. In some embodiments, the holder 20 and / or structures and / or features adjacent to the holder 20 support or facilitate the positioning of the workpieces 10 and 12 relative to each other according to a predetermined geometry while the workpiece 12 is brought into contact with the adhesive material 14.

[0029] In some embodiments, the workpiece 12 is formed from a single plate or workpiece section of metal, while in other embodiments, the workpiece 12 is formed from two or more workpiece sections of metal, which may be of the same metal or of different metals. In some examples, the workpiece is made of an aluminum alloy. A non-limiting example of an aluminum alloy (AA) is an aluminum alloy of the 5000 series, e.g., AA5182 or similar, with magnesium, manganese, and optionally other alloying elements as minor constituents, wherein a substantial portion of the remaining remainder consists of aluminum.

[0030] With reference to the Fig. In steps 3-5 and 7, the process 100 is continued by contacting a surface 34 of the workpiece 10 with an electrode 36 and a surface 38 of the workpiece 12 with an electrode 40. As shown in the figure, the electrodes 36 and 40 are connected to a power source 42. Electric current from the power supply 42 is passed jointly through the electrodes 36 and 40 (e.g., anode and cathode, respectively, or vice versa) and flows through the workpieces 10 and 12 to generate resistance heating (box 106) in the workpieces 10 and 12 under processing conditions. The heat generated in workpieces 10 and 12 is rapidly transferred to the adjacent adhesive material 14 to partially cure the adhesive material 14 and to bond workpieces 10 and 12 together, forming a partially cured, adhesive-bonded workpiece assembly 44. As shown in Fig. As shown in Figure 7, the partially cured adhesive material 14 has a degree of curing of about 20% to about 75% in some embodiments, for example about 35% to about 70%.

[0031] In one or more embodiments of the disclosure and as described in the Fig. As shown in Figures 4A-4B and 5, the processing conditions include generating an electric current of about 1.5 kA to about 2.5 kA between electrodes 36 and 40 for a time of about 1.5 seconds to about 2.5 seconds to generate temperatures of about 200°C to about 375°C in areas of the workpieces 10 and 12 that come into contact with or are adjacent to the adhesive 14. In some embodiments, the temperatures generated in the workpieces 10 and 12 may be substantially the same or different. For example, a steel-based workpiece 10 may achieve a higher temperature (e.g., 250°C to about 375°C) than an aluminum-based workpiece 12 (e.g., 200°C to about 275°C) by resistance heating under the processing conditions.In some embodiments, the processing conditions include the electrodes 36 and 40 exerting a force of about 3 kN to about 5 kN on the workpieces 10 and 12 to press the adhesive bead 30 between the workpieces to a relatively thin adhesive thickness of about 100 µm to about 4000 µm while it is still in liquid or pasty form (e.g. before the adhesive 14 has fully or partially hardened).

[0032] As in Fig. As shown in Figure 3, the electrodes 36 and 40 each have a corresponding longitudinal axis (indicated by double-headed arrows 46 and 48), a corresponding electrode surface 50, 52 that comes into contact with the corresponding workpieces 10, 12, and a corresponding electrode body 54, 56 that supports the corresponding electrode surface 50, 52. In some embodiments, the corresponding electrode surface 50, 52 has a maximum area dimension transverse to the corresponding longitudinal axis 46, 48 of approximately 8 millimeters (mm) to approximately 40 mm. In some embodiments, the corresponding electrode body 54, 56 has a maximum body dimension transverse to the corresponding longitudinal axis 46, 48 of approximately 8 mm to approximately 13 mm. In some embodiments, the corresponding electrode surface 50, 52 has a circular, oval, polygonal, or curved shape, or a combination thereof.Advantageously, a relatively large corresponding electrode area 50, 52 with a relatively small corresponding electrode body 54, 56 improves the rapid heating of the metal areas of the workpieces 10, 12 in the vicinity of the adhesive material 14 in order to accelerate the rapid partial hardening of the adhesive material 14 within a relatively short cycle time.

[0033] With reference to the Fig. 6-7, the process 100 is continued by removing the partially cured, adhesive-bonded workpiece assembly 44 from the device 20 and conveying the partially cured, adhesive-bonded workpiece assembly 44 downstream for further processing. In one or more embodiments of the disclosure, the further downstream processing comprises exposing the partially cured, adhesive-bonded workpiece assembly 44 (Box 108) to heat under processing conditions to substantially cure the adhesive 14. In some embodiments, the processing conditions comprise conveying the partially cured, adhesive-bonded workpiece assembly 44 to an oven 58, which operates to generate an oven internal temperature of about 150°C to about 200°C.In some embodiments, the partially cured workpiece assembly 44, bonded with adhesive material, is exposed to the internal oven temperature for a period of approximately 15 to 25 minutes. As in . Fig. As shown in Figure 7, the substantially fully cured adhesive material 14 has in some embodiments a degree of curing of about 85% to about 100%, such as about 90% to about 100%, for example about 95% to about 100%.

Claims

[1] A method (100) for joining several workpieces (10, 12), the method (100) comprising: Application (102) of adhesive material (14) to a first workpiece (10); Bringing (104) a second workpiece (12) into contact with the adhesive material (14) so ​​that the adhesive material (14) is located between the first workpiece (10) and the second workpiece (12); Contacting (106) of the first workpiece (10) with a first electrode (36) prior to generating (106) a resistance heating; Contacting (106) the second workpiece (12) with a second electrode (40) before generating (106) the resistance heating; Generating (106) resistance heating in the first workpiece (10) and the second workpiece (12) under initial processing conditions to partially cure the adhesive (14) and to join the first workpiece (10) and the second workpiece (14) together to form a partially cured workpiece assembly (44) bonded with adhesive (14); and Exposure (108) of the partially cured workpiece assembly (44) bonded with the adhesive (14) to heat under second processing conditions in order to substantially cure the adhesive (14); wherein the adhesive (14) is a thermosetting adhesive system containing polymers, polymer precursors and / or reactive components, and is in the form of a liquid or paste which cross-links or otherwise hardens depending on temperature and time; wherein the first processing conditions comprise an electric current between the first electrode (36) and the second electrode (40) of 1.5 kA to 2.5 kA, which is generated for a time of 1.5 seconds to 2.5 seconds and is effective to generate a temperature of about 200°C to about 375°C in the first workpiece (10) and the second workpiece (12); wherein the first processing conditions involve applying a force of about 3 kN to about 5 kN through the first electrode (36) and the second electrode (40) to the first workpiece (10) and the second workpiece (12); and where the second processing conditions include a temperature of approximately 150°C to approximately 200°C and a duration of approximately 15 minutes to approximately 25 minutes. [2] Method (100) according to claim 1, wherein generating (106) the resistance heating comprises generating (106) the resistance heating in the first workpiece (10) and the second workpiece (12) under the first processing conditions, which include applying a force to the first workpiece (10) and the second workpiece (12) by the first electrode (36) and the second electrode (40) to compress the adhesive material (14) between the first workpiece (10) and the second workpiece (12) to a thickness of about 100 µm to about 4000 µm. [3] A system (20, 58) for joining several workpieces (10, 12), the system () comprising: a dispenser (24) that is operational, to apply adhesive material (14) to a first workpiece (10), wherein the adhesive material (14) is a thermosetting adhesive system containing polymers, polymer precursors and / or reactive components, and is in the form of a liquid or paste that cross-links or otherwise hardens depending on temperature and time; a holder (20) that is capable of supporting the first workpiece (10) while a second workpiece (12) is brought into contact with the adhesive material (14), so that the adhesive material (14) is arranged between the first workpiece (10) and the second workpiece (12); a first electrode (36) that is operational to contact the first workpiece (10); a second electrode (40) capable of contacting the second workpiece (12), wherein the first electrode (36) and the second electrode (40) are operable together to generate resistance heating in the first workpiece (10) and the second workpiece (12) under initial processing conditions to partially cure the adhesive (14) and to join the first workpiece (10) and the second workpiece (12) together to form a partially cured workpiece assembly (44) bonded with the adhesive (14); and a heating arrangement (58) capable of generating heat to which the partially cured workpiece arrangement bonded with adhesive (14) is exposed under second processing conditions in order to substantially cure the adhesive (14); wherein the first processing conditions comprise an electric current between the first electrode (36) and the second electrode (40) of 1.5 kA to 2.5 kA, which is generated for a time of 1.5 seconds to 2.5 seconds and is effective to generate a temperature of about 200°C to about 375°C in the first workpiece (10) and the second workpiece (12); wherein the first processing conditions involve applying a force of about 3 kN to about 5 kN through the first electrode (36) and the second electrode (40) to the first workpiece (10) and the second workpiece (12); and where the second processing conditions include a temperature of approximately 150°C to approximately 200°C and a duration of approximately 15 minutes to approximately 25 minutes. [4] System (20, 58) according to claim 3, wherein the first electrode (36) and the second electrode (40) each have a corresponding longitudinal axis (46, 48) and each comprise: a corresponding electrode surface (50, 52) which forms an interface with a corresponding surface of the first workpiece (10) and the second workpiece (12), and wherein the corresponding electrode surface (50, 52) has a maximum area dimension transverse to the corresponding longitudinal axis (46, 48) of approximately 8 mm to approximately 40 mm; and a corresponding electrode body (54, 56) which carries the corresponding electrode surface (50, 52), and wherein the corresponding electrode body (54, 56) has a maximum body dimension transverse to the corresponding longitudinal axis (46, 48) of about 8 mm to about 13 mm.

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