Aluminum alloy material defect reproduction method and defect screening method

Abstract

The present application belongs to the technical field of aluminum alloy material defect detection, and particularly relates to an aluminum alloy material defect reproduction method and a defect screening method. The aluminum alloy material defect reproduction method comprises the following steps: selecting an aluminum alloy profile containing hidden impurities as a test base material, identifying and positioning defects of the test base material; sequentially performing bending processing and brazing high-temperature processing on the test base material after the defect identification and positioning; placing the test base material after the brazing high-temperature processing in an electrochemical environment for power-on processing; and performing normal temperature standing processing on the test base material after the power-on processing. The aluminum alloy material defect reproduction method can completely simulate the evolution process of hidden impurities in the aluminum alloy profile in the actual production and processing and use process, fully expand the originally hidden defects into observable leakage failure defects, solve the problem that the prior art cannot actively reproduce such defects in the early stage and is difficult to carry out root cause analysis, and provide a repeatable verification test basis for studying the defect formation and expansion mechanism.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy material defect detection technology, specifically relating to a method for reproducing defects in aluminum alloy materials and a method for screening defects. Background Technology

[0002] Currently, most water-channel radiators are assembled using aluminum alloy profiles that have been bent and brazed. Due to their advantages of light weight, high thermal conductivity, and compact structure, they are widely used in various industrial equipment and heat exchange applications. However, during mass production and actual use, leaks frequently occur in finished water-channel radiators. Preliminary fault tracing reveals that the leaks are mainly caused by inherent hidden defects in the aluminum alloy profiles. Traditional industry testing methods, relying solely on conventional non-destructive testing, cannot accurately detect these deep-seated, high-risk defects, making it difficult to achieve quality control from the outset.

[0003] Current standard inspection methods at the manufacturing stage can only detect external defects, macroscopic cracks, and visible internal defects. However, subtle internal problems within the profiles are difficult to identify at the manufacturing stage. These defects will gradually corrode and expand during subsequent processing, storage, and use, eventually causing leakage problems in the cavity. Existing technologies cannot accurately locate the root cause of the defects or clarify the mechanism of failure formation.

[0004] Furthermore, current industry practices for addressing radiator leakage issues largely rely on post-incident disassembly and analysis. This lack of comprehensive and feasible end-to-end operational simulation and verification methods makes it impossible to accurately predict the evolution and failure processes of profile defects at different stages, such as bending, high-temperature brazing, power-on operation, and room-temperature resting. Consequently, it's difficult to proactively remove defective materials and substandard semi-finished products during raw material warehousing and production. This situation not only increases product repair costs but also leads to poor overall stability of the radiator system. Summary of the Invention

[0005] The purpose of this invention is to provide a method for reproducing defects in aluminum alloy materials and a method for screening defects.

[0006] The first aspect of this application provides a method for reproducing defects in aluminum alloy materials, comprising the following steps: An aluminum alloy profile containing hidden impurities was selected as the test substrate, and the defects of the test substrate were identified and located. The test substrate, after defect identification and location were completed, was sequentially subjected to bending and high-temperature brazing treatment. The test substrate, after being brazed at high temperature, was placed in an electrochemical environment for electrochemical treatment. The test substrate, after being electrically treated, was left to stand at room temperature.

[0007] In one embodiment of this application, the latent impurity is an inclusion impurity with a particle size greater than 50 μm.

[0008] In one embodiment of this application, CT scanning is used to complete the defect identification and location.

[0009] In one embodiment of this application, the process parameters for bending include: bending angular velocity of 120±5° / s, bending angle of 95±5°, clamping time of 1s, and bending delay time of 0.3s.

[0010] In one embodiment of this application, the high-temperature brazing treatment includes placing the bent test substrate in a high-temperature brazing environment.

[0011] In one embodiment of this application, the parameters of the electrochemical environment include: applying a 24V voltage and continuously applying the voltage for 24 hours.

[0012] In one embodiment of this application, the time for the room temperature standing treatment is 6 to 10 days.

[0013] The second aspect of this application provides a method for screening defects in aluminum alloy materials, characterized by comprising the following steps: Aluminum alloy profiles containing hidden impurities of different particle sizes were selected as test substrates, and defects were identified and located on the test substrates. The test substrate, after defect identification and location were completed, was sequentially subjected to bending and high-temperature brazing treatment. The test substrate, after being brazed at high temperature, was placed in an electrochemical environment for electrochemical treatment. The test substrate after being electrically treated was then left to stand at room temperature. The minimum particle size of latent impurities that cause penetration leakage defects in waterway sections is defined as the control particle size.

[0014] In one embodiment of this application, the particle size of the latent impurity is distributed in a stepped manner.

[0015] In one embodiment of this application, at least one of the following technical features is included: The defect identification and location were completed using CT scanning. The bending process parameters include: bending angular velocity 120±5° / s, bending angle 95±5°, clamping time 1s, and bending delay time 0.3s. The high-temperature brazing treatment includes: placing the bent test substrate in a high-temperature brazing environment; The parameters of the electrochemical environment include: applying a voltage of 24V and continuously applying the current for 24 hours; The time for the room temperature standing treatment is 6 to 10 days.

[0016] The beneficial effects of this invention are: The aluminum alloy material defect reproduction method of the present invention can completely simulate the evolution process of hidden impurities inside aluminum alloy profiles during actual production, processing and use, allowing the defects that were originally hidden to fully expand into observable leakage failure defects. It solves the problem that the existing technology cannot actively reproduce such defects in the early stage and it is difficult to carry out root cause analysis, and provides a repeatable experimental basis for studying the defect formation and expansion mechanism.

[0017] The aluminum alloy material defect screening method of the present invention can identify the minimum control particle size of impurities that will eventually cause leakage failure by statistically analyzing the defect expansion results of latent impurities of different particle sizes. This provides clear control indicators for incoming inspection of aluminum alloy raw materials, helps to remove profiles containing high-risk defects in advance during the production process, reduces the risk of subsequent leakage from the source, effectively reduces the rework rate of finished products, and improves the overall stability of water-type aluminum alloy radiators.

[0018] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a preferred embodiment of the method for reproducing defects in aluminum alloy materials according to the present invention; Figure 2 This is a flowchart of a preferred embodiment of the aluminum alloy material defect screening method of the present invention; Figure 3 This is a schematic diagram illustrating the development of defects in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram illustrating the development of defects in Embodiment 2 of the present invention; Figure 5 This is a schematic diagram illustrating the development of defects in Embodiment 3 of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Water-cooled radiators are prone to leakage and failure during use. To identify the root cause of the malfunction, the inventors conducted a systematic failure analysis on the leaking radiator. They compared and tested the raw material hardness, chemical composition, and tensile strength of the leaking component and a normal component. The results showed no significant difference in hardness and chemical composition, ruling out these factors as the cause of the leak. Mechanical performance testing revealed that the leaking component had a lower elongation rate, thus focusing the investigation on issues related to material elongation.

[0024] Further investigation was conducted from multiple dimensions, including raw material composition and performance, bending process, production equipment status, forming mold parameters, and product usage environment, to identify potential causes. Multiple sets of comparative tests and data analysis were performed, closely simulating actual production processes and usage conditions. Ultimately, it was confirmed that the core cause of the radiator leakage was the presence of foreign matter inclusions inside and on the surface of the aluminum alloy profile. Due to the difference in electrochemical potential between the foreign matter and the aluminum alloy matrix, electrochemical corrosion was triggered under the influence of moisture, continuously eroding the defective area and expanding gaps and pores. Even when the product was stored statically, oxygen and moisture in the air would cause natural oxidation and corrosion at the defective areas, causing the micro-defects to extend and connect, eventually forming leakage channels and leading to radiator leakage.

[0025] This application provides a method for reproducing defects in aluminum alloy materials and a method for screening defects, which are described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments of this application. Furthermore, in the following embodiments, the descriptions of each embodiment have their own emphasis; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments.

[0026] See Figure 1 One embodiment of this application provides a method for reproducing defects in aluminum alloy materials, comprising the following steps: An aluminum alloy profile containing hidden impurities was selected as the test substrate, and the defects of the test substrate were identified and located. The test substrate, after defect identification and location were completed, was sequentially subjected to bending and high-temperature brazing treatment. The test substrate, after being brazed at high temperature, was placed in an electrochemical environment for electrochemical treatment. The test substrate, after being electrically treated, was left to stand at room temperature.

[0027] In one embodiment, the latent impurity is an inclusion impurity with a particle size greater than 50 μm, and the defect identification and location can be completed by CT scanning.

[0028] Furthermore, the bending process parameters include: bending angular velocity 120±5° / s, bending angle 95±5°, clamping time 1s, and bending delay time 0.3s.

[0029] Due to the significant difference in electrochemical potential between impurities and foreign matter within the profile and the aluminum alloy matrix, the material inherently possesses a risk of corrosion failure. The sample is first bent according to a predetermined process. The mechanical force generated during bending further reduces the elongation properties of the aluminum alloy matrix and simultaneously causes stress concentration in the impurity areas. Existing minor defects are further stretched and expanded, continuously amplifying potential internal defects. After bending, stress concentration occurs in areas with latent impurities, forming hidden internal defects.

[0030] Furthermore, the high-temperature brazing treatment includes placing the bent test substrate in a high-temperature brazing environment. Hidden impurities in the test substrate will undergo localized dissolution.

[0031] Furthermore, the parameters of the electrochemical environment include: applying a 24V voltage and continuously energizing for 24 hours.

[0032] Under the combined effects of high-temperature brazing thermal shock and electrochemical environment, the interface between impurities and aluminum matrix undergoes continuous electrochemical corrosion reaction. Corrosive media continuously penetrate into the defects, causing the original gaps and holes in the profile to gradually widen and deepen.

[0033] Furthermore, the time for the room temperature standing treatment is 6 to 10 days.

[0034] During the period when the product is stored at room temperature, the oxygen and water vapor in the ambient air will continue to act on the defective area, causing long-term oxidation and corrosion on the damaged parts. This will cause the micro-damage to extend, expand, and gradually connect with each other, eventually forming a through-type water seepage channel in the radiator water channel, which will eventually cause the radiator water channel to leak. This fully reproduces the leakage problem caused by raw material impurities and defects during actual production and use.

[0035] See Figure 3 , Figure 4 and Figure 5The figures below illustrate the defect development in Examples 1, 2, and 3. The raw material used in all three examples is AL3003, differing only in the morphology of internal impurities. The experimental procedure is as follows: First, CT scanning was performed on the raw materials to screen out samples with impurity defects larger than 50 μm in internal size. Then, according to the actual processing conditions of the product, the samples underwent bending, high-temperature brazing, energized operation, and room-temperature storage in sequence. The evolution of impurity morphology, size, and corrosion state was observed throughout the process, successfully reproducing the waterway leakage failure phenomenon caused by internal impurity defects in the raw materials. The corresponding figures for the three examples fully record the morphological evolution of defect impurities during the full-process reproduction experiment. Comparison shows that bending, high-temperature brazing, energized operation, and room-temperature storage all act individually or in combination on the internal impurities of the material, collectively accelerating the corrosion rate at the defects and promoting the continuous development of corrosion defects.

[0036] The aluminum alloy material defect reproduction method of this embodiment can completely simulate the entire process of how hidden impurities inside aluminum alloy profiles gradually expand from minor hidden dangers to penetrating leakage defects during actual production, processing and use. It fully exposes hidden defects that could not be identified during the factory inspection stage, and provides a repeatable and verifiable test scheme for conducting failure mechanism research and troubleshooting the root cause of failure. It solves the technical problem in the prior art that can only perform post-event analysis after leakage occurs and cannot actively and directionally reproduce the defect evolution process.

[0037] Based on the defect reproduction method of aluminum alloy materials, defects can be screened for hidden impurities of different particle sizes, and the smallest impurity particle size that will cause leakage can be identified as the control threshold for raw material incoming inspection.

[0038] Based on this, one embodiment of this application also provides a method for screening defects in aluminum alloy materials, including the following steps: Multiple aluminum alloy profiles containing hidden impurities of different particle sizes were selected as test substrates, and defects were identified and located on the test substrates. The test substrate, after defect identification and location were completed, was sequentially subjected to bending and high-temperature brazing treatment. The test substrate, after being brazed at high temperature, was placed in an electrochemical environment for electrochemical treatment. The test substrate after being electrically treated was then left to stand at room temperature. The minimum particle size of latent impurities that cause penetration leakage defects in waterway sections is defined as the control particle size.

[0039] Optionally, the particle size of the latent impurities is distributed in a stepped manner. For example, the particle size of the latent impurities in multiple aluminum alloy profiles can be 50μm, 55μm, 60μm, 65μm, 70μm, etc.

[0040] In this embodiment, defect identification and location, bending processing, high-temperature brazing treatment, electrical treatment, and room-temperature static treatment can be performed in the same way as the aluminum alloy material defect reproduction method in the above embodiments, and will not be described again here.

[0041] After being left to stand at room temperature, the defects on each test substrate can be observed. The smallest particle size of the latent impurities corresponding to the test substrates showing penetration leakage defects is defined as the control particle size. This clarifies the impurity control threshold for incoming aluminum alloy raw materials, providing a clear and actionable standard for the testing process. During incoming inspection, the particle size of impurities in the aluminum alloy profiles is compared with this control particle size. All profiles with impurity particle sizes greater than or equal to the control particle size are removed. This filters out raw materials with high leakage risks at the source, enabling quality control at the production front end. This significantly reduces the probability of leakage failure in subsequent production, processing, and finished product use, effectively reducing rework costs and improving the product quality and operational stability of aluminum alloy water channel radiators.

[0042] For example, when the particle size of the latent impurities in the test substrate where a penetration leakage defect occurs is 60μm, 65μm, or 70μm, then 60μm can be determined as the impurity control threshold.

[0043] In summary, this invention fully reconstructs the entire evolution process of latent impurities in aluminum alloys from their hidden state to causing leakage failure through a defect reproduction method. This solves the long-standing industry problem of being unable to actively reproduce such defects and conduct root cause mechanism research. Simultaneously, the defect screening method clarifies the minimum control particle size of impurities that can cause leakage failure, providing clear and specific control indicators for incoming raw material inspection. This helps to preemptively eliminate raw materials containing high-risk defects in the production process, reducing the leakage risk of aluminum alloy heat sinks from the source, effectively reducing finished product rework costs, and improving product stability.

[0044] It should be noted that all the devices (parts whose specific structures are not specified) selected in this application are general standard parts or parts known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for reproducing defects in aluminum alloy materials, characterized in that, Includes the following steps: An aluminum alloy profile containing hidden impurities was selected as the test substrate, and the defects of the test substrate were identified and located. The test substrate, after defect identification and location were completed, was sequentially subjected to bending and high-temperature brazing treatment. The test substrate, after being brazed at high temperature, was placed in an electrochemical environment for electrochemical treatment. The test substrate, after being electrically treated, was left to stand at room temperature.

2. The method for reproducing defects in aluminum alloy materials according to claim 1, characterized in that, The latent impurities are inclusions with a particle size greater than 50 μm.

3. The method for reproducing defects in aluminum alloy materials according to claim 1, characterized in that, The defect was identified and located using CT scans.

4. The method for reproducing defects in aluminum alloy materials according to claim 1, characterized in that, The bending process parameters include: bending angular velocity 120±5° / s, bending angle 95±5°, clamping time 1s, and bending delay time 0.3s.

5. The method for reproducing defects in aluminum alloy materials according to claim 1, characterized in that, The high-temperature brazing treatment includes placing the bent test substrate in a high-temperature brazing environment.

6. The method for reproducing defects in aluminum alloy materials according to claim 1, characterized in that, The parameters of the electrochemical environment include: applying a voltage of 24V and continuously applying the current for 24 hours.

7. The method for reproducing defects in aluminum alloy materials according to claim 1, characterized in that, The time for the room temperature standing treatment is 6 to 10 days.

8. A method for screening defects in aluminum alloy materials, characterized in that, Includes the following steps: Aluminum alloy profiles containing hidden impurities of different particle sizes were selected as test substrates, and defects were identified and located on the test substrates. The test substrate, after defect identification and location were completed, was sequentially subjected to bending and high-temperature brazing treatment. The test substrate, after being brazed at high temperature, was placed in an electrochemical environment for electrochemical treatment. The test substrate after being electrically treated was then left to stand at room temperature. The minimum particle size of latent impurities that cause penetration leakage defects in waterway sections is defined as the control particle size.

9. The method for screening defects in aluminum alloy materials according to claim 8, characterized in that, The particle size of the latent impurities is distributed in a stepped manner.

10. The method for screening defects in aluminum alloy materials according to claim 8, characterized in that, Includes at least one of the following technical features: The defect identification and location were completed using CT scanning. The bending process parameters include: bending angular velocity 120±5° / s, bending angle 95±5°, clamping time 1s, and bending delay time 0.3s. The high-temperature brazing treatment includes: placing the bent test substrate in a high-temperature brazing environment; The parameters of the electrochemical environment include: applying a voltage of 24V and continuously applying the current for 24 hours; The time for the room temperature standing treatment is 6 to 10 days.

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