Method for testing binding force of plating layer of aluminum-plated copper composite material

Abstract

The invention discloses a method for testing the binding force of a plating layer of an aluminum-plated copper composite material, which comprises the following steps: selecting an aluminum-plated copper composite material with a proper thickness, and carrying out low-temperature annealing pretreatment; welding a copper wire or a copper strip on the copper surface of the aluminum-plated copper composite material; 3) setting stripping test environment parameters; stripping the copper wire or the copper strip at a constant speed by adopting a stripping test system and recording a three-dimensional stripping force vector and an interface crack propagation form; the unit area binding energy is calculated through an energy integration method, and meanwhile, the binding strength is comprehensively evaluated by combining fractal dimension analysis of the stripping surface. According to the method, the aluminum-plated copper composite material is subjected to low-temperature annealing, machining stress is eliminated, then copper wires or copper strips are welded through the pulse micro-beam plasma welding technology, the heat affected zone is reduced by about 60% while the connection strength is guaranteed, interface weakening caused by traditional tin soldering is avoided, the three-dimensional stripping force vector is combined with fractal dimension analysis, and the welding quality of the copper wires or the copper strips is improved. The traditional single stripping force index is broken through, and the test precision is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a method for testing the bonding strength of a coating of an aluminum-copper-plated composite material. Background Art

[0002] Aluminum-coated copper composites are composite materials formed by continuously laminating a certain thickness of copper or copper alloy strips to one or both sides of an aluminum or aluminum alloy substrate using methods such as continuous casting, semi-molten rolling, or vacuum sputtering and water electroplating. This composite material achieves a metallurgical bond in its structure, fully leveraging the excellent properties of both copper and aluminum, retaining the electrical conductivity of copper and the thermal conductivity and lightweight properties of aluminum, thereby optimizing and improving material performance. However, since aluminum-coated copper composites are newly developed products and have not yet been applied on a large scale in the market, there are no group, industry, or national testing standards for them. The industry only uses 3M transparent tape or repeated bending to test the bonding strength between copper and aluminum. There is no quantitative data to measure this, and there are no fixed testing standards.

[0003] Based on this, the present invention discloses a method for testing the bonding strength of an aluminum-copper-plated composite material coating. Summary of the Invention

[0004] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide a method for testing the bonding strength of the coating of an aluminum-copper composite material.

[0005] In order to achieve the above-mentioned purpose and the above-mentioned technical effect, the technical solution adopted by the present invention is:

[0006] A method for testing the bonding strength of an aluminum-copper composite coating comprises the following steps:

[0007] 1) Select aluminum-copper composite material of appropriate thickness and perform low-temperature annealing pretreatment;

[0008] 2) Soldering copper wire or copper strip to the copper surface of the aluminum-copper composite material;

[0009] 3) Set the peel test environment parameters;

[0010] 4) Using a peeling test system to uniformly peel the copper wire or copper strip and record the three-dimensional peeling force vector and interface crack propagation morphology;

[0011] 5) The unit area binding energy is calculated by the energy integration method, and the bonding strength is comprehensively evaluated by combining the fractal dimension analysis of the peeling surface.

[0012] Furthermore, in step 1), the thickness of the aluminum-copper composite material is 20-100 μm, and the aluminum-copper composite material is cut into samples with a length*width of 10-15 cm*3-8 cm, and then kept at 80-130°C for 10-30 minutes to complete low-temperature annealing pretreatment.

[0013] Furthermore, in step 2), a pulsed micro-beam plasma welding process is used to weld the copper wire or copper strip to the copper surface of the aluminum-copper composite material under the protection of an inert gas, and the welding heat-affected zone is controlled within 2 times the diameter of the weld spot.

[0014] Furthermore, in step 2), when the pulsed micro-plasma welding process is adopted, the current in the arc starting stage is controlled at 55-90A / 0.1-0.3s, the current in the arc maintaining stage is controlled at 35-55A / 0.5-1s, and the current in the arc ending stage is controlled at 25-35A / 0.2-0.5s.

[0015] Furthermore, in step 2), the diameter of the copper wire is 0.5-1.5 mm.

[0016] Furthermore, in step 3), the peeling test environment parameters include:

[0017] Temperature: 25±0.5℃;

[0018] Humidity: 50±5%RH;

[0019] Vibration isolation: frequency > 100Hz.

[0020] Furthermore, in step 4), a peeling tester is used and the peeling speed is controlled at 0.2-2 mm / s.

[0021] Furthermore, in step 4), the peeling test system includes:

[0022] Connectors, used to connect to copper wire or copper tape, and the bonding strength is tested by applying a force to the connector in a direction away from the aluminum layer;

[0023] Six-axis force sensor for recording the three-dimensional peeling force vector.

[0024] Furthermore, in step 5), the binding energy per unit area E b The calculation formula is:

[0025]

[0026] Wherein, w is the peeling width, L is the peeling length, and F(x) is the real-time peeling force.

[0027] Furthermore, in step 5), the fractal dimension of the peeling surface is 1.2-1.8.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention discloses a method for testing the bonding strength of the coating of an aluminum-copper composite material. The aluminum-copper composite material is first subjected to low-temperature annealing to eliminate processing stress, and then a pulsed micro-beam plasma welding process is used to weld copper wires or copper strips. While ensuring the connection strength, the heat-affected zone is reduced by about 60%, avoiding the interface weakening caused by traditional tin soldering. The method combines three-dimensional peeling force vectors and fractal dimension analysis, breaking through the traditional single peeling force indicator and achieving higher test accuracy. DETAILED DESCRIPTION

[0030] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0031] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be provided later.

[0032] A method for testing the bonding strength of an aluminum-copper composite coating comprises the following steps:

[0033] 1) Select aluminum-copper composite materials with a thickness of 20-100μm, cut them into samples with a length*width of 10-15cm*3-8cm, and then heat them at 80-130℃ for 10-30min to complete low-temperature annealing pretreatment to eliminate processing stress and improve test accuracy;

[0034] 2) Using pulsed micro-plasma welding technology, under the protection of inert gas such as nitrogen, the copper wire or copper strip is welded to the copper surface of the aluminum-copper composite material, and the heat-affected zone of the welding is controlled within 2 times the diameter of the welding point;

[0035] 3) Set the peel test environment parameters:

[0036] Temperature: 25±0.5℃;

[0037] Humidity: 50±5%RH;

[0038] Vibration isolation: frequency>100Hz;

[0039] 4) Use a peeling test system to uniformly peel the copper wire or copper strip at a speed of 0.2-2 mm / s, and record the three-dimensional peeling force vector and interface crack propagation morphology;

[0040] 5) Calculate the binding energy per unit area by energy integration method, the binding energy per unit area E b The calculation formula is:

[0041]

[0042] Wherein, w is the peeling width, L is the peeling length, and F(x) is the real-time peeling force;

[0043] At the same time, the fractal dimension of the peeling surface (1.2-1.8) is combined with the analysis to comprehensively evaluate the bonding strength. The larger the fractal dimension of the peeling surface, the more irregular the peeling surface, and the more complex the branching and interlacing of the crack propagation path. If the interface bonding is strong, more energy is required to tear the interface. The smaller the fractal dimension of the peeling surface, the smoother the peeling surface, and the crack propagation path tends to be straight. If the interface bonding is weak, brittle peeling is likely to occur.

[0044] In step 2), when the pulsed micro-plasma welding process is used, the current in the arc starting stage is controlled at 55-90A / 0.1-0.3s, the current in the arc maintaining stage is controlled at 35-55A / 0.5-1s, and the current in the arc ending stage is controlled at 25-35A / 0.2-0.5s.

[0045] In step 2), the diameter of the copper wire is 0.5-1.5 mm.

[0046] In step 4), the peeling test system includes:

[0047] Connectors, used to connect to copper wire or copper tape, and the bonding strength is tested by applying a force to the connector in a direction away from the aluminum layer;

[0048] Six-axis force sensor for recording the three-dimensional peeling force vector.

[0049] If it is necessary to record the interface crack propagation morphology, a high-speed camera can be set up.

[0050] Example 1

[0051] A method for testing the bonding strength of an aluminum-copper composite coating comprises the following steps:

[0052] 1) Select an aluminum-copper composite material with a thickness of 100 μm, cut the aluminum-copper composite material into samples with a length and width of 10 cm and 5 cm, and then perform a low-temperature annealing pretreatment at 100°C for 20 minutes;

[0053] 2) Using pulsed micro-plasma welding technology, under nitrogen gas protection, a copper wire with a diameter of 1 mm was welded to the copper surface of the aluminum-copper composite material, and the heat-affected zone of the welding was controlled within 1.5 times the diameter of the weld point;

[0054] 3) Set the peel test environment parameters:

[0055] Temperature: 25℃;

[0056] Humidity: 50% RH;

[0057] Vibration isolation: frequency 200Hz;

[0058] 4) Using a peeling test system to uniformly peel the copper wire or copper strip and record the three-dimensional peeling force vector and interface crack propagation morphology;

[0059] 5) The unit area binding energy is calculated by the energy integration method, and the bonding strength is comprehensively evaluated by combining the fractal dimension analysis of the peeling surface.

[0060] In step 2), when the pulsed micro-plasma welding process is used, the current in the arc starting stage is controlled at 60A / 0.1-0.3s, the current in the arc maintaining stage is controlled at 40A / 0.5-1s, and the current in the arc ending stage is controlled at 30A / 0.2-0.5s.

[0061] In step 4), the peeling speed is controlled at 0.2 mm / s.

[0062] In step 4), the peeling test system includes:

[0063] Connectors, used to connect to copper wire or copper tape, and the bonding strength is tested by applying a force to the connector in a direction away from the aluminum layer;

[0064] Six-axis force sensor for recording the three-dimensional peeling force vector.

[0065] In step 5), the binding energy per unit area E b The calculation formula is:

[0066]

[0067] Wherein, w is the peeling width, L is the peeling length, and F(x) is the real-time peeling force.

[0068] In step 5), the fractal dimension of the peeling surface is 1.5.

[0069] Example 2

[0070] A method for testing the bonding strength of an aluminum-copper composite coating comprises the following steps:

[0071] 1) Select an aluminum-copper composite material with a thickness of 80 μm, cut the aluminum-copper composite material into samples with a length and width of 15 cm and 5 cm, and then heat it at 120°C for 30 minutes to complete the low-temperature annealing pretreatment;

[0072] 2) Using pulsed micro-plasma welding technology, under nitrogen gas protection, a copper wire with a diameter of 1.5 mm was welded to the copper surface of the aluminum-coated copper composite material, and the heat-affected zone of the welding was controlled within 1.5 times the diameter of the weld point;

[0073] 3) Set the peel test environment parameters:

[0074] Temperature: 25℃;

[0075] Humidity: 55% RH;

[0076] Vibration isolation: frequency 200Hz;

[0077] 4) Using a peeling test system to uniformly peel the copper wire or copper strip and record the three-dimensional peeling force vector and interface crack propagation morphology;

[0078] 5) The unit area binding energy is calculated by the energy integration method, and the bonding strength is comprehensively evaluated by combining the fractal dimension analysis of the peeling surface.

[0079] In step 2), when the pulsed micro-plasma welding process is used, the current in the arc starting stage is controlled at 80A / 0.1-0.3s, the current in the arc maintaining stage is controlled at 50A / 0.5-1s, and the current in the arc ending stage is controlled at 25A / 0.2-0.5s.

[0080] In step 4), the peeling speed is controlled at 1 mm / s.

[0081] In step 4), the peeling test system includes:

[0082] Connectors, used to connect to copper wire or copper tape, and the bonding strength is tested by applying a force to the connector in a direction away from the aluminum layer;

[0083] Six-axis force sensor for recording three-dimensional peeling force vectors;

[0084] High-speed camera used to record the interface crack growth morphology.

[0085] In step 5), the binding energy per unit area E b The calculation formula is:

[0086]

[0087] Wherein, w is the peeling width, L is the peeling length, and F(x) is the real-time peeling force.

[0088] In step 5), the fractal dimension of the peeling surface is 1.8.

[0089] The rest is the same as Example 1.

[0090] Example 3

[0091] A method for testing the bonding strength of an aluminum-copper composite coating comprises the following steps:

[0092] 1) Select an aluminum-copper composite material with a thickness of 40 μm, cut the aluminum-copper composite material into samples with a length and width of 10 cm and 5 cm, and then heat it at 120°C for 10 minutes to complete the low-temperature annealing pretreatment;

[0093] 2) Using pulsed micro-plasma welding technology, under nitrogen gas protection, a copper wire with a diameter of 1.2 mm was welded to the copper surface of the aluminum-coated copper composite material, and the heat-affected zone of the welding was controlled within 1.5 times the diameter of the weld point;

[0094] 3) Set the peel test environment parameters:

[0095] Temperature: 25.5℃;

[0096] Humidity: 45% RH;

[0097] Vibration isolation: frequency 200Hz;

[0098] 4) Using a peeling test system to uniformly peel the copper wire or copper strip and record the three-dimensional peeling force vector and interface crack propagation morphology;

[0099] 5) The unit area binding energy is calculated by the energy integration method, and the bonding strength is comprehensively evaluated by combining the fractal dimension analysis of the peeling surface.

[0100] In step 2), when the pulsed micro-plasma welding process is used, the current in the arc starting stage is controlled at 80A / 0.1-0.3s, the current in the arc maintaining stage is controlled at 50A / 0.5-1s, and the current in the arc ending stage is controlled at 25A / 0.2-0.5s.

[0101] In step 4), the peeling speed is controlled at 1 mm / s.

[0102] In step 4), the peeling test system includes:

[0103] Connectors, used to connect to copper wire or copper tape, and the bonding strength is tested by applying a force to the connector in a direction away from the aluminum layer;

[0104] Six-axis force sensor for recording the three-dimensional peeling force vector.

[0105] In step 5), the binding energy per unit area E b The calculation formula is:

[0106]

[0107] Wherein, w is the peeling width, L is the peeling length, and F(x) is the real-time peeling force.

[0108] In step 5), the fractal dimension of the peeling surface is 1.2.

[0109] The rest is the same as Example 1.

[0110] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0111] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for testing the bonding strength of aluminum-copper composite coatings, characterized in that: The following steps are involved: 1) Select aluminum-copper composite material of appropriate thickness and perform low-temperature annealing pretreatment; 2) Soldering copper wire or copper strip to the copper surface of the aluminum-copper composite material; 3) Set the peel test environment parameters; 4) Using a peeling test system to uniformly peel the copper wire or copper strip and record the three-dimensional peeling force vector and interface crack propagation morphology; 5) The unit area binding energy is calculated by the energy integration method, and the bonding strength is comprehensively evaluated by combining the fractal dimension analysis of the peeling surface.

2. The method for testing the bonding strength of an aluminum-copper composite coating according to claim 1, wherein: In step 1), the aluminum-copper composite material has a thickness of 20-100 μm, and the aluminum-copper composite material is cut into samples with a length*width of 10-15 cm*3-8 cm, and then kept at 80-130°C for 10-30 minutes to complete low-temperature annealing pretreatment.

3. The method for testing the bonding strength of an aluminum-copper composite coating according to claim 1, wherein: In step 2), a pulsed micro-beam plasma welding process is used to weld the copper wire or copper strip to the copper surface of the aluminum-copper composite material under the protection of an inert gas, and the welding heat-affected zone is controlled within 2 times the diameter of the weld spot.

4. The method for testing the bonding strength of an aluminum-copper composite coating according to claim 3, wherein: In step 2), when the pulsed micro-plasma welding process is used, the current in the arc starting stage is controlled at 55-90A / 0.1-0.3s, the current in the arc maintaining stage is controlled at 35-55A / 0.5-1s, and the current in the arc ending stage is controlled at 25-35A / 0.2-0.5s.

5. The method for testing the coating adhesion of an aluminum-copper composite material according to claim 1, wherein: In step 2), the diameter of the copper wire is 0.5-1.5 mm.

6. The method for testing the coating adhesion of an aluminum-copper composite material according to claim 1, wherein: In step 3), the peeling test environment parameters include: Temperature: 25±0.5℃; Humidity: 50±5%RH; Vibration isolation: frequency > 100Hz.

7. The method for testing the bonding strength of aluminum-copper composite coatings according to claim 1, wherein: In step 4), a peeling tester is used and the peeling speed is controlled at 0.2-2 mm / s.

8. The method for testing the coating adhesion of an aluminum-copper composite material according to claim 1, wherein: In step 4), the peeling test system includes: Connectors, used to connect to copper wire or copper tape, and the bonding strength is tested by applying a force to the connector in a direction away from the aluminum layer; Six-axis force sensor for recording the three-dimensional peeling force vector.

9. The method for testing the coating adhesion of an aluminum-copper composite material according to claim 1, wherein: In step 5), the binding energy per unit area E b The calculation formula is: Wherein, w is the peeling width, L is the peeling length, and F(x) is the real-time peeling force.

10. The method for testing the coating adhesion of an aluminum-copper composite material according to claim 1, wherein: In step 5), the fractal dimension of the peeling surface is 1.2-1.8.

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