Method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys
By analyzing the heat treatment and magnetization curves of copper-chromium-zirconium alloys, the problem of evaluating the solid solubility of chromium was solved, enabling accurate evaluation of the properties of copper alloys and promoting the development of high-strength copper alloys.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINALCO DAYE COPPER PLATE & STRIP CO LTD
- Filing Date
- 2022-10-28
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies lack effective means to assess the solid solubility of chromium in copper-chromium-zirconium alloys, a key factor affecting the performance of the alloy, making it difficult to improve mechanical strength and electrical properties.
After heat treatment of standard copper-chromium-zirconium alloy samples, the solid solubility of chromium was analyzed using magnetization curves, including annealing and quenching steps. Combined with magnetic testing methods, different degrees of solid solubility of chromium were distinguished.
This provides a simple and effective method to accurately assess the solid solution degree of chromium in a copper matrix, which helps in the development of high-strength and high-performance copper alloys.
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Figure CN115616064B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of material microstructure and composition testing, and in particular to a method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys. Background Technology
[0002] Copper is favored in many fields due to its excellent electrical properties and relatively low cost, but the low mechanical strength of pure copper significantly limits its application. To address this issue, patent CN202110754666.6 discloses a high-strength, high-conductivity copper-chromium alloy and its preparation method. By adding chromium alloying elements to the copper matrix, a copper-chromium supersaturated solid solution is obtained, thereby enhancing the properties of the copper matrix. However, this method suffers from poor Cr phase stability, which easily grows and coarsens, affecting the mechanical properties of the alloy. Patent CN202210123882.5 further discloses a method for manufacturing ultrafine-grained copper-chromium-zirconium plates and copper alloy plates. This method introduces Zr elements to refine the Cr phase in the alloy and performs multi-layer rolling and heat treatment on the basis of a saturated solid solution to control the precipitation of strengthening phases at grain boundaries, thereby more efficiently improving the mechanical strength of the material.
[0003] Copper-chromium-zirconium alloy is a typical precipitation-strengthened copper alloy, achieving a strength of 600 MPa while maintaining a conductivity of approximately 80% IACS (International Annealed Copper Standard). At the eutectic temperature, the solubility of chromium and zirconium in copper is 0.73% and 0.11%, respectively, while at room temperature, their solubility is less than 0.03% and 0.01%. This demonstrates a significant difference in solubility between high and low temperatures. This difference forms the theoretical basis for the dispersed precipitation of the second phase in copper-chromium-zirconium alloys during low-temperature aging. The dispersed precipitation of the second phase significantly hinders dislocation movement, thereby increasing the material's strength. At high temperatures, the alloying elements are fully dissolved in the copper matrix, promoting dispersed precipitation strengthening at low temperatures, which is one of the key factors influencing the alloy's performance.
[0004] As shown above, to improve the mechanical strength and electrical properties of copper-chromium-zirconium alloys, it is necessary to assess the degree of solid solution of the second phase within the material and then proceed accordingly based on the assessment results. However, currently, professional testing and characterization methods for the degree of solid solution of the alloy phase in the copper matrix are still relatively lacking, with scanning tunneling microscopy (SEM) being the primary method. However, SEM can only capture optical information from the sample surface, and even probing the cross-section of the sample involves considerable randomness. Summary of the Invention
[0005] Therefore, it is necessary to provide a method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys to address at least one of the problems mentioned above.
[0006] This invention application provides a method for evaluating the solid solubility of chromium in a copper-chromium-zirconium alloy, wherein the alloy contains 0.3%–1.4% chromium, 0.02%–0.20% zirconium, less than 0.2% impurities, and the remainder is Cu. The evaluation method includes the following steps:
[0007] A standard sample block of copper-chromium-zirconium alloy was obtained by shearing, and the standard sample block was cleaned.
[0008] The standard sample block is heat-treated to obtain the standard sample block to be tested. The heat treatment includes annealing and quenching.
[0009] The magnetization curve of the standard sample to be tested is measured, and the solid solubility of chromium in the copper-chromium-zirconium alloy is analyzed based on the magnetization curve.
[0010] In one embodiment, the step of cleaning the standard sample block includes polishing the surface of the standard sample block to remove the oxide layer and impurities on the surface of the standard sample block, and then spraying with alcohol and wiping with lint-free paper.
[0011] In one embodiment, the annealing temperature in the heat treatment is 800–1000°C, and the holding time during the annealing process is 1–4 hours.
[0012] In one embodiment, the annealing is performed under a protective atmosphere.
[0013] In one embodiment, the step of testing the magnetization curve of the standard sample to be tested includes: moving the standard sample to be tested into a comprehensive physical property measurement system or a vibrating sample magnetometer, and testing the magnetization curve of the sample at a temperature of 10K to 50K.
[0014] In one embodiment, the magnetic field strength ranges from 0 to 60 kOe and the magnetization ranges from 0 to 10 emu / g in the step of testing the magnetization curve of the sample at a temperature of 10 K to 50 K.
[0015] In one embodiment, the step of analyzing the solid solubility of chromium in the copper-chromium-zirconium alloy includes:
[0016] When the maximum value of the magnetization intensity in the magnetization curve is less than or equal to 0.2 Gauss, the solid solution degree of chromium in the copper matrix is considered to be low.
[0017] When the maximum value of the magnetization is less than or equal to 0.8 Gauss, the solid solution degree of chromium in the copper matrix is considered to be moderate.
[0018] When the maximum value of the magnetization is less than or equal to 10 Gauss, the solid solubility of chromium in the copper matrix is considered to be highly solid.
[0019] In one embodiment, the standard sample block is in the form of a block or sheet.
[0020] The technical solutions provided in the embodiments of the present invention bring the following beneficial technical effects:
[0021] The method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys provided by this invention involves heat-treating standard samples of the alloy and then performing magnetic tests. The degree of solid solubility of chromium is determined by the obtained magnetization curve. This method has a simple and clear mechanism and can significantly distinguish copper-chromium-zirconium alloys with different degrees of chromium solid solubility. It provides a feasible standard for testing the degree of solid solubility of different elements in copper alloys, thereby facilitating the efficient development of high-performance copper alloys with high strength as the main characteristic.
[0022] Additional aspects and advantages of this application will be set forth in the following sections and will be understood in detail from the following description, or may be learned by specific practice of the invention. Attached Figure Description
[0023] Figure 1 This is a schematic flowchart of a method for evaluating the solid solubility of chromium in a copper-chromium-zirconium alloy according to an embodiment of the present invention.
[0024] Figure 2 This is a schematic diagram of the magnetization curves of copper-chromium-zirconium alloys in various embodiments of the present invention;
[0025] Figure 3 The images shown are scanning tunneling microscope images of copper-chromium-zirconium alloy samples after annealing at 800℃, 900℃, and 1000℃ for 1 hour in various embodiments of the present invention (a corresponds to 800℃, b corresponds to 900℃, and c corresponds to 1000℃). Detailed Implementation
[0026] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Possible embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein with reference to the drawings. The embodiments described with reference to the drawings are exemplary and intended to provide a more thorough and complete understanding of the disclosure of the invention, and should not be construed as limiting the invention. Furthermore, detailed descriptions of known techniques may be omitted where such details are not essential to the features of the illustrated invention.
[0027] Those skilled in the art will understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the prior art and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.
[0028] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in the specification of this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that the term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.
[0029] The technical solution of the present invention and how the technical solution solves the above-mentioned technical problems will be described in detail below with specific embodiments.
[0030] This invention application provides a method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys. The alloy contains 0.3%–1.4% chromium, 0.02%–0.20% zirconium, less than 0.2% impurities, and the remainder is Cu. Figure 1 As shown, the evaluation method includes the following steps:
[0031] S100: Prepare standard samples of copper-chromium-zirconium alloy by shearing and clean the standard samples. Cut sub-centimeter-sized copper sheets or blocks from the cold-rolled copper-chromium-zirconium alloy. For the shearing step, the copper-chromium-zirconium alloy needs to be cut into standard sizes to facilitate subsequent aging treatment and magnetic testing. Optionally, the standard samples can be in block or sheet form, with a length of 0.6–0.9 cm and a width of 0.3–0.6 cm. Optionally, the cleaning step of the standard samples includes surface grinding to remove the oxide layer and impurities, followed by alcohol spraying and wiping with lint-free paper to further clean the sample surface of impurities and residual sandpaper particles.
[0032] S200: The standard sample block is heat-treated to obtain the standard sample block to be tested. The heat treatment includes annealing and quenching.
[0033] S300: Test the magnetization curve of the standard sample to be tested, and analyze the solid solubility of chromium in copper-chromium-zirconium alloy based on the magnetization curve.
[0034] The method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys provided by this invention involves heat-treating standard samples of the alloy and then performing magnetic tests. The degree of solid solubility of chromium is determined by the obtained magnetization curve. This method has a simple and clear mechanism and can significantly distinguish copper-chromium-zirconium alloys with different degrees of chromium solid solubility. It provides a feasible standard for testing the degree of solid solubility of different elements in copper alloys, thereby facilitating the efficient development of high-performance copper alloys with high strength as the main characteristic.
[0035] Optionally, in one embodiment of this application, the annealing temperature in the heat treatment is 800–1000°C, and the holding time during the annealing process is 1–4 hours. For the annealing step, a tube furnace can be used, and the tube material must be able to withstand high annealing temperatures. Multiple sets of samples can be tested, for example, at least three sets of tests at different annealing temperatures, with a certain temperature gradient between each set. Optionally, annealing is performed under a protective atmosphere. Before heating, the quartz tube needs to be cleaned by purging with a protective atmosphere. After reaching the set temperature, it is kept constant to simulate the aging process in the copper-chromium-zirconium alloy process, allowing the chromium element to be fully dissolved.
[0036] Optionally, in one embodiment of this application, in the heat treatment of S200, the quenching specifically involves: immediately removing the sample after the annealing step and immersing it in water for rapid quenching. For the quenching step, the sample must be removed immediately after the annealing step and transferred to pre-prepared cool water for rapid cooling. The operation should be rapid, and care should be taken to avoid damaging the sample during the transfer process.
[0037] Optionally, in another embodiment of this application, the step of testing the magnetization curve of the standard sample to be tested includes: transferring the standard sample to be tested into a physical property measurement system or a vibrating sample magnetometer, and testing the magnetization curve of the sample at a temperature of 10K to 50K. Specifically, in the step of testing the magnetization curve of the sample at a temperature of 10K to 50K, the magnetic field strength ranges from 0 to 60 kOe, and the magnetization strength ranges from 0 to 10 emu / g. The physical property measurement system (PPMS) or vibrating sample magnetometer (VSM) uses currently available equipment.
[0038] Specifically, in another embodiment of this application, the step of analyzing the solid solubility of chromium in copper-chromium-zirconium alloy includes:
[0039] When the maximum value of the magnetization intensity in the magnetization curve is less than or equal to 0.2 Gauss, the solid solution degree of chromium in the copper matrix is considered to be low.
[0040] When the maximum value of the magnetization is less than or equal to 0.8 Gauss, the solid solution degree of chromium in the copper matrix is considered to be moderate.
[0041] When the maximum value of the magnetization is less than or equal to 10 Gauss, the solid solubility of chromium in the copper matrix is considered to be highly solid.
[0042] The following are specific examples:
[0043] Example 1:
[0044] (1) Cutting. Cut three standard-sized, regularly shaped copper sheets of copper-chromium-zirconium alloy, each measuring 0.5cm × 0.8cm.
[0045] (2) Cleaning. Polish the surface of the copper sheet to remove any oxide layer and impurities that may be present on the surface, and use alcohol spray and lint-free paper to wipe it to further clean the impurities and residual sandpaper particles on the sample surface.
[0046] (3) Annealing. A tube furnace was used. The sample was placed in the center of the constant temperature zone of the tube furnace and aligned with the temperature probe to keep the sample temperature as consistent as possible with the temperature displayed on the tube furnace. After placement, nitrogen gas was introduced for 15 minutes to ensure that impurity gas molecules inside the tube were cleaned. The target temperature for the sample was 800℃. After setting the target annealing temperature, the temperature inside the tube furnace was maintained at a constant temperature for 1 hour after the temperature rose from room temperature to the annealing temperature.
[0047] (4) Cold quenching. Immediately after the annealing step, remove the sample and transfer it to pre-prepared cool water for rapid cooling. The operation should be quick, and care should be taken to avoid damaging the sample during the transfer process.
[0048] (5) Testing. After the cold quenching step, remove the sample, blot dry with filter paper, repeat the cleaning process, and then transfer it to the comprehensive physical property measurement system. Test the magnetization curve (MH curve) of the sample at 10K. For example... Figure 2 As shown. After the test, the sample in the sample tube must be retrieved, and the equipment must be shut down for maintenance.
[0049] Example 2
[0050] The rest of the content is the same as in Example 1, except that the target temperature during the annealing process is 900°C.
[0051] Example 3
[0052] The rest of the content is the same as in Example 1, except that the target temperature during the annealing process is 1000°C.
[0053] Data analysis was performed on the above embodiments:
[0054] like Figure 2As shown, when the annealing temperature is 800℃, the MH curve is a curve, and the maximum magnetization is less than or equal to 0.2 Gauss, indicating that the solid solution degree of chromium in the copper matrix of the copper-chromium-zirconium alloy is low. When the annealing temperature is 900℃, the MH curve is a slightly curved straight line, and the maximum magnetization is less than or equal to 0.8 Gauss, indicating that the solid solution degree of chromium in the copper matrix of the copper-chromium-zirconium alloy after annealing at this temperature is moderate. When the annealing temperature is 1000℃, the MH curve is a straight line, and the maximum magnetization is less than or equal to 10 Gauss, indicating that the solid solution degree of chromium in the copper matrix of the copper-chromium-zirconium alloy is high.
[0055] like Figure 3 As shown, a comparison of the results from magnetic testing and scanning tunneling microscopy reveals that the characterization results from scanning tunneling microscopy are consistent with those from magnetic testing. Specifically, the samples at the three temperatures exhibited low, medium, and high solid solution levels, respectively, with the sample annealed at 800℃ showing the lowest solid solution level and the sample annealed at 1000℃ showing the highest. This demonstrates that using magnetic testing to assess the solid solution level of the second phase in copper-chromium-zirconium alloys has very high reliability.
[0056] Those skilled in the art will understand that the steps, measures, and solutions in the various operations, methods, and processes discussed in this application can be alternated, modified, combined, or deleted. Furthermore, other steps, measures, and solutions in the various operations, methods, and processes discussed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and solutions in the prior art that are similar to those disclosed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted.
[0057] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.
[0058] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.
[0059] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
Claims
1. A method for evaluating the solid solubility of chromium in a copper-chromium-zirconium alloy, wherein the copper-chromium-zirconium alloy contains 0.3%–1.4% chromium, 0.02%–0.20% zirconium, less than 0.2% impurities, and the remainder is Cu, characterized in that… Includes the following steps: A standard sample block of copper-chromium-zirconium alloy was obtained by shearing, and the standard sample block was cleaned. The standard sample block is heat-treated to obtain the standard sample block to be tested. The heat treatment includes annealing and quenching. The magnetization curve of the standard sample to be tested is obtained by transferring the standard sample to a comprehensive physical property measurement system or a vibrating sample magnetometer and testing it at a temperature of 10K to 50K. Based on the magnetization curve, the solid solubility of chromium in the copper-chromium-zirconium alloy is analyzed, including: when the maximum value of the magnetization intensity in the magnetization curve is less than or equal to 0.2 Gauss, the solid solubility of chromium in the copper matrix is considered to be low; when the maximum value of the magnetization intensity is less than or equal to 0.8 Gauss, the solid solubility of chromium in the copper matrix is considered to be moderate; when the maximum value of the magnetization intensity is less than or equal to 10 Gauss, the solid solubility of chromium in the copper matrix is considered to be high.
2. The method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys according to claim 1, characterized in that, The step of cleaning the standard sample block includes polishing the surface of the standard sample block to remove the oxide layer and impurities on the surface of the standard sample block, and then spraying with alcohol and wiping with lint-free paper.
3. The method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys according to claim 1, characterized in that, The annealing temperature in the heat treatment is 800-1000℃, and the holding time during the annealing process is 1-4 hours.
4. The method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys according to claim 3, characterized in that, The annealing is performed under a protective atmosphere.
5. The method for evaluating the solid solubility of chromium in copper-chromium-zirconium alloys according to claim 1, characterized in that, The standard sample block is in block or sheet form.