High-strength corrosion-resistant gold-based shape memory alloy as well as preparation method and application thereof
Gold-based shape memory alloys were prepared by compounding Au, Ag, Cu, Zn, Ti, Al and In in specific proportions, which solved the problems of insufficient brittleness and corrosion resistance of existing gold-based alloy materials under high strength. This resulted in a combination of high strength, corrosion resistance and martensitic memory effect, making it suitable for aerospace and medical fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-17
- Publication Date
- 2026-04-03
AI Technical Summary
Existing gold-based alloy materials suffer from brittleness under high strength and insufficient corrosion resistance, making it difficult to meet the high requirements of fields such as aerospace and medical.
Gold-based shape memory alloys were prepared by blending Au, Ag, Cu, Zn, Ti, Al and In in a specific ratio. Through alloy melting, casting and heat treatment, martensite and austenite phases were formed, and the microstructure was optimized to improve strength and corrosion resistance.
The prepared alloy exhibits excellent high strength and corrosion resistance, possesses a good martensitic memory effect, and is suitable for corrosive environments, as well as for applications in aerospace and medical fields.
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Figure CN121780925A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of shape memory alloy preparation technology, specifically to an ultra-high strength corrosion-resistant gold-based shape memory alloy, its preparation method, and its application. Background Technology
[0002] With the continuous advancement of modern technology, the demand for materials with high strength, high corrosion resistance, and shape memory function is gradually increasing. In aerospace, medical, and electronics fields, shape memory alloys are gradually becoming important engineering materials due to their excellent performance.
[0003] Currently, most gold-based alloy materials on the market focus on their strength and corrosion resistance, but research on gold-based alloys that combine martensitic shape memory effect with high strength and corrosion resistance is relatively limited. For example, traditional Au-Cu-Al shape memory alloys may exhibit brittleness at high strength and insufficient corrosion resistance, failing to meet the demands of demanding industrial applications. Summary of the Invention
[0004] Therefore, it is necessary to provide a high-strength, corrosion-resistant gold-based shape memory alloy, its preparation method, and its application.
[0005] The technical solution adopted in this application is as follows: A high-strength, corrosion-resistant gold-based shape memory alloy, wherein the gold-based shape memory alloy contains Au as the main component, and also contains the following other components in weight percentage: Ag 5%~15%, Cu 3%~5%, Zn 2%~3%, Ti 1%~2%, Al 0.1%~0.5%, and In 0%~0.5%.
[0006] Preferably, the In content in the gold-based shape memory alloy is 0.1-0.4%.
[0007] This application provides a method for preparing the above-mentioned high-strength corrosion-resistant gold-based shape memory alloy, including the following steps: obtaining the component raw materials of the gold-based shape memory alloy, melting, casting, heat treatment, cold working and forming.
[0008] Preferably, the smelting process conditions are: temperature of 1100 ~ 1650 ℃.
[0009] Preferably, the casting process involves pouring molten alloy into a mold and cooling it to form an ingot.
[0010] Preferably, the heat treatment process involves placing the ingot at 600-700℃ for 1-2 hours for solution treatment.
[0011] The gold-based shape memory alloy of this application forms martensite and austenite phases with good shape memory effect in the alloy through alloy melting, casting and heat treatment. Then, through appropriate cooling process and solution treatment, the microstructure of the alloy is further optimized, so that it still has good martensitic memory effect while having high strength and good corrosion resistance.
[0012] This application also provides the application of the above-mentioned high-strength, corrosion-resistant gold-based shape memory alloy in the fabrication of engineering structural components.
[0013] Compared with existing technologies, the core technological advantages and beneficial effects of this application are as follows: This application presents a high-strength, corrosion-resistant gold-based shape memory alloy prepared by compounding Au, Ag, Cu, Zn, Ti, Al, and In in a specific ratio. It combines high strength, excellent corrosion resistance, and martensitic memory effect. In particular, it can maintain good mechanical properties and shape memory properties even in extreme environments such as corrosion, making it suitable for fields such as aerospace and medical where high corrosion resistance is required. Attached Figure Description
[0014] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.
[0015] Figure 1 Photographs (a) of the alloy smelting product prepared in Example 1 and (b) of the alloy after rolling.
[0016] Figure 2 The image shows the DSC temperature rise curve of the alloy prepared in Example 1.
[0017] Figure 3 The image shows the DSC cooling curve of the alloy prepared in Example 1. Detailed Implementation
[0018] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0021] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.
[0022] The technical concept of this application is to prepare a gold-based shape memory alloy by compounding Au, Ag, Cu, Zn, Ti, Al and In in a specific ratio. Through alloy melting, casting and heat treatment, martensite and austenite phases with good shape memory effect are formed in the alloy. Then, through appropriate cooling process and solution treatment, the microstructure of the alloy is further optimized so that it simultaneously has high strength, corrosion resistance and martensitic memory effect.
[0023] The present application will be further described in detail below with reference to specific embodiments, so that those skilled in the art can more clearly understand the present application. The following embodiments are only used to illustrate the present application, and are not intended to limit the scope of the present application. Based on the specific embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present application. In the embodiments of the present application, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art; in the embodiments of the present application, unless specifically specified, the technical means used are all conventional means well known to those skilled in the art.
[0024] Key raw material sources and their descriptions: Au: Purity ≥ 99.99%, foil material.
[0025] Ag: Purity ≥ 99.99%, granules.
[0026] Cu: Purity ≥ 99.99%, granular.
[0027] Zn: Purity ≥ 99.99%, granular.
[0028] Ti: Purity ≥ 99.99%, foil material.
[0029] Al: Purity ≥ 99.99%, in bulk form.
[0030] In: Purity ≥ 99.99%, granules.
[0031] The following example illustrates this.
[0032] Example 1 This embodiment provides a gold-based shape memory alloy, which is prepared from the following raw materials in weight percentages: 84% Au, 8% Ag, 4% Cu, 2% Zn, 1.5% Ti, 0.3% Al and 0.2% In.
[0033] The preparation method of the gold-based alloy in this embodiment includes the following steps: S1, Preparation of alloy raw materials.
[0034] The raw materials for preparing gold-based alloys are obtained according to the mass ratio.
[0035] S2, smelting.
[0036] Preheat the graphite crucible to 400℃, and place a 0.3wt% (w / w) borax covering agent at the bottom as a filling material. Add Au, Ag, Cu, Ti, Al, and In particles, place them in a vacuum melting furnace, close the furnace door, evacuate, and purge with argon to standard atmospheric pressure. Raise the temperature to 1550±10℃ and melt for 10 minutes, using electromagnetic stirring to ensure the matrix is completely liquid. Subsequently, reduce the power and control the melt temperature to 1200℃, perform a second addition of the remaining Zn, and vibrate the crucible to stir. After the alloy is completely melted, a molten alloy is obtained.
[0037] S3, casting.
[0038] The molten alloy is air-cooled in a melting furnace to obtain a cast alloy.
[0039] S4, heat treatment.
[0040] The as-cast alloy was solution treated at 650°C for 2 hours to promote a complete austenitic transformation.
[0041] S5, after cold working and forming.
[0042] The product is prepared by air cooling, further processing by hot rolling, and then polishing.
[0043] The product was characterized in terms of structure and properties. (1) Hardness test method: refer to the micro Vickers hardness test in the "Methods for Hardness Test of Precious Metal Jewelry" (T / SZS 4018-2020).
[0044] (2) Salt spray test method: Refer to the salt spray test in "Artificial Atmosphere Corrosion Test" (GB / T 10125-2021), and count the mass loss after the salt spray test to show the corrosion resistance of the alloy.
[0045] (3) Phase transition temperature Af test: The specific steps are as follows: Take 10~20mg of sample, place it in the DSC sample crucible, wash the gas three times, raise the temperature from Mf-30℃ to Af+30℃ at a rate of 10K / min, keep it at this temperature for a period of time, and then cool it down to Mf-30℃ at a rate of 10K / min to form one thermal cycle.
[0046] Record As, Ms, M f A f Ms is the temperature at which the parent phase begins to transform into martensite. f As is the temperature at which the martensitic phase transformation is complete (reaching almost 100% volume fraction), and As is the temperature at which martensite begins its reverse phase transformation into the parent phase upon heating. f This is the temperature at which the reverse phase transition is completed. (4) Deformation recovery capability test: Prepare specimens with L=(1-2) or (2.5-3.5)d according to (GB / T 44030-2024). Test the deformation recovery ability of the specimens at 200℃ with the compression endpoints of 1%, 2%, 3%, 4%, and 5% strain and the unloading endpoint of 0 stress, and record the maximum deformation percentage.
[0047] (6) For compressive strength testing, please refer to the "Metallic Materials Room Temperature Compression Test Method" (GB / T 7314-2017).
[0048] (5) The ability to maintain good mechanical properties and shape memory properties under extreme environments such as corrosion is demonstrated by the fact that after the salt spray test, the above indicators were retested and there was no significant change.
[0049] The test results are summarized in the table below: Example 1: Performance Test Statistics Table of Gold-Based Alloys As can be seen from the table above: The alloy product prepared in this embodiment has a hardness greater than 260 HV, a compressive strength greater than 440 MPa, good corrosion resistance, a phase transformation temperature slightly higher than that of traditional Ni-Ti alloys, and no significant change in alloy properties after salt spray testing.
[0050] Example 2 This embodiment provides a gold-based shape memory alloy, which is prepared from the following raw materials in weight percentages: 86.2% Au, 7% Ag, 3% Cu, 2% Zn, 1% Ti, 0.5% Al and 0.3% In.
[0051] The method for preparing the gold-based shape memory alloy in this embodiment is basically the same as that in Example 1. The difference is: (1) Smelting step S2: The temperature was raised to 1600±10℃ and melted for 12 minutes using electromagnetic stirring to ensure the matrix was completely liquid. Then, the power was reduced to control the melt temperature at 1150℃, and a second feeding was performed, while the crucible was vibrated and stirred. Once the alloy was completely melted, a molten alloy was obtained.
[0052] (2) Heat treatment step S4: The as-cast alloy was solution treated at 650°C for 1.5 hours.
[0053] Refer to the test method steps in Example 1 to perform structural and performance characterization on the gold-based alloy product.
[0054] The test results are summarized in the table below: Example 2: Performance Test Statistics Table of Gold-Based Alloys As can be seen from the table above: The alloy product prepared in this embodiment still maintains high hardness, high strength, and good corrosion resistance, and the alloy properties show no significant change after salt spray testing.
[0055] Example 3 This embodiment provides a gold-based shape memory alloy, which is prepared from the following raw materials in weight percentages: 78.5% Au, 12% Ag, 4% Cu, 3% Zn, 2% Ti, 0.1% Al, and 0.4% In. The preparation method of the gold-based shape memory alloy in this embodiment is basically the same as that in Embodiment 1, except for the melting step S2: Heat to 1580±10℃ and melt for 15 minutes, using electromagnetic stirring to ensure the matrix is completely liquid. Then, reduce the power and control the melt temperature to 1200℃.
[0056] The structure and properties of the gold-based alloy products were characterized.
[0057] The test results are summarized in the table below: Example 3: Performance Test Statistics Table of Gold-Based Alloys As can be seen from the table above: The alloy product prepared in this embodiment still maintains high hardness, high strength, good corrosion resistance, and a phase transformation temperature slightly higher than that of traditional Ni-Ti alloys. The alloy properties did not change significantly after the salt spray test.
[0058] Example 4 This embodiment provides a gold-based shape memory alloy, which is prepared from the following raw materials in weight percentages: 81.2% Au, 10% Ag, 5% Cu, 2% Zn, 1.5% Ti, 0.2% Al and 0.1% In.
[0059] The preparation method of the gold-based shape memory alloy in this embodiment is basically the same as that in Example 1, except for the melting step S2: The temperature was raised to 1580±10℃ and melted for 14 minutes using electromagnetic stirring to ensure the matrix was completely liquid. Then, the power was reduced to control the melt temperature at 1200℃, and the remaining Zn and borax were added for a second feeding, while the crucible was vibrated and stirred. After the alloy was completely melted, a molten alloy was obtained.
[0060] The structure and properties of the gold-based alloy products were characterized.
[0061] The test results are shown in the table below: Example 4: Performance Test Statistics Table of Gold-Based Alloys As can be seen from the table above: The alloy product prepared in this embodiment still maintains high hardness, high strength, good corrosion resistance, and a phase transformation temperature slightly higher than that of traditional Ni-Ti alloys. The alloy properties did not change significantly after the salt spray test.
[0062] Comparative Example 1 This comparative example provides a conventional Ni-Ti based alloy with the composition: Ti-50Ni.
[0063] The structure and properties of the above-mentioned Ni-Ti based alloys were characterized. The test results are shown in the table below: Comparative Example 1: Performance Test Statistics of Ni-Ti Based Alloy Comparative Example 2 This comparative example provides a gold-based alloy with the following composition: 86.2% Au, 7% Ag, 3% Cu, 2% Zn, 1% Ti, 0.5% Al, and 0.3% In. This experimental example of the gold-based alloy does not contain any Cu or Zn raw materials. The preparation method is described in Example 1.
[0064] Referring to the test method and procedures in Example 1, the structure and properties of the gold-based alloy product were characterized. The test results showed that the alloy exhibited stress-induced martensitic transformation and a memory effect.
[0065] In addition, the inventors' team discovered through extensive laboratory research that: 1. The balance between strength and shape memory effect in the alloy of this application is mainly achieved by preparing it by blending Au, Ag, Cu, Zn, Ti, Al, and In in a specific ratio. When the content of Cu, Zn, and Ti decreases, the alloy lacks phases capable of martensitic transformation, and the maximum deformation of the alloy decreases.
[0066] 2. Compared with Ni-Ti shape memory alloys, the alloy prepared in this application exhibits enhanced corrosion resistance. Through composition optimization, the alloy demonstrates greater stability in corrosive environments and maintains excellent performance during long-term use.
[0067] 3. Compared with traditional Ni-Ti based alloys, the gold-based shape memory alloy of this application is simpler in terms of material ratio and production process, which can reduce production costs and has a wider range of application prospects.
[0068] 4. This application essentially provides a gold-based alloy that combines excellent shape memory effect, high strength and high corrosion resistance, and can exhibit better stability in harsher environments, making it particularly suitable for aerospace, medical devices and high-requirement industrial fields.
[0069] It should be noted that the above embodiments are only for further elaboration and explanation of the technical solution of this application, and are not intended to further limit the technical solution of this application. The method of this application is only a preferred implementation and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A high-strength, corrosion-resistant gold-based shape memory alloy, characterized in that, The gold-based shape memory alloy contains Au as its main component, and also contains the following other components by weight percentage: Ag 5%~15%, Cu 3%~5%, Zn 2%~3%, Ti 1%~2%, Al 0.1%~0.5%, and In 0%~0.5%.
2. The high-strength, corrosion-resistant gold-based shape memory alloy according to claim 1, characterized in that, The gold-based shape memory alloy contains Au as its main component, and also contains the following other components by weight percentage: Ag 5%~15%, Cu 3%~5%, Zn 2%~3%, Ti 1%~2%, Al 0.1%~0.5%, and In 0.1%~0.4%.
3. The method for preparing the high-strength, corrosion-resistant gold-based shape memory alloy according to claim 1 or 2, characterized in that, Includes the following steps: Obtain the component raw materials of the gold-based shape memory alloy as described in claim 1 or 2; Smelting; Casting; Heat treatment; Cold working and forming.
4. The method for preparing the high-strength, corrosion-resistant gold-based shape memory alloy according to claim 3, characterized in that, The smelting process conditions are: temperature of 1100 ~ 1650 ℃.
5. The method for preparing the high-strength, corrosion-resistant gold-based shape memory alloy according to claim 4, characterized in that, The casting process involves pouring molten alloy into a mold and cooling it to form an ingot.
6. The method for preparing the high-strength, corrosion-resistant gold-based shape memory alloy according to claim 5, characterized in that, The heat treatment process involves placing the ingot at 600-700℃ for 1-2 hours for solution treatment.
7. The application of the high-strength, corrosion-resistant gold-based shape memory alloy as described in claim 1 or 2 in the preparation of engineering structural components.