A method for additive manufacturing of a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy

Abstract

The application provides a wide-temperature-range super-elastic polycrystalline copper-aluminum-manganese alloy additive manufacturing method, which comprises the following steps: step 1, pretreating copper-aluminum-manganese raw materials; step 2, weighing the required mass of the pretreated copper-aluminum-manganese raw materials according to a fixed component proportion; step 3, electric arc smelting the copper-aluminum-manganese raw materials after component proportioning to obtain copper-aluminum-manganese alloy ingots; step 4, atomizing the copper-aluminum-manganese alloy ingots to obtain copper-aluminum-manganese alloy powder; step 5, 3D printing and in-situ secondary melting the copper-aluminum-manganese alloy powder, and wire cutting the copper-aluminum-manganese alloy sample after printing; and step 6, stress relief heat treatment of the copper-aluminum-manganese alloy sample to obtain a polycrystalline copper-aluminum-manganese alloy. The application can prepare a polycrystalline copper-aluminum-manganese alloy with excellent super-elasticity without solid solution treatment through component design and laser additive manufacturing method, and the alloy has controllable morphology, small grain size, uniform composition and favorable texture, and has large super-elastic strain and complete reverse phase transition.

Description

Technical Field

[0001] This invention belongs to the field of materials and metals technology, and more specifically, relates to an additive manufacturing method for a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy. Background Technology

[0002] Deep space exploration is a crucial direction in my country's strategy to become a space power. As the exploration range continues to expand, the demands on materials are also increasing. Take the landing buffer device for deep spacecraft as an example. It is a key device that further decelerates the spacecraft and absorbs its kinetic energy during landing, reducing damage to internal components from the impact. Traditional landing buffer devices mostly use materials such as honeycomb aluminum for energy absorption, primarily utilizing the plastic deformation during material crushing to absorb energy. The drawback of this method is that it can only provide single-use buffering. In recent years, the concept of "leapfrog exploration" has been proposed for deep space exploration, meaning that spacecraft need to take off and land multiple times on the surface of extraterrestrial bodies to achieve multi-location exploration of the celestial surface. Based on this, the "Leap Forward" mission places more complex performance requirements on the buffer material: (1) It should have a large deformation capacity and be recoverable after unloading, so as to achieve a good buffering effect while meeting the purpose of reuse; (2) It should have a small critical deformation stress, so as to ensure that the buffer deforms first, thereby protecting the internal precision instruments; (3) It should have a wide temperature range to adapt to the strong temperature difference in deep space and extraterrestrial regions; (4) It should have a large deformation stress hysteresis and good energy absorption capacity; (5) It should have good cycle stability and be able to be reused multiple times. The superelastic properties of shape memory alloys basically meet the above performance requirements and are potential application materials.

[0003] Copper-aluminum-manganese alloys are shape memory alloys with excellent properties, characterized by low critical transformation stress and adjustable transformation temperature. However, achieving superelasticity capable of stable cycling over a wide temperature range with large strain presents the following main challenges:

[0004] 1. Due to the strong anisotropy of copper-aluminum-manganese alloys, stress concentration will occur at locations with different orientations, such as the triangular grain boundaries. During cycling, the stress concentration locations are prone to cracking.

[0005] Second, the slip resistance during loading is relatively close to the superelastic critical phase transformation stress, making it prone to plastic deformation during cyclic loading.

[0006] Third, the alloy has a clear tendency to grow grains. The solid solution temperature is relatively high, and the grains are easy to grow. After traditional melting and solid solution, it is very easy to obtain grown grains, and it is impossible to produce fine grain structure.

[0007] Fourth, the material unloading reverse phase transformation process has large resistance and residual martensite, making it difficult to produce complete superelasticity and excellent cycle performance.

[0008] To address the above-mentioned limitations on the performance of copper-aluminum-manganese alloys, the present invention proposes the following solutions: (1) For problems one and three, materials are prepared by laser powder bed melting. Utilizing the high cooling rate of laser treatment and the advantage of uniform alloy powder composition, uniform fine grains can be generated, achieving a micron-level grain distribution, increasing the grain boundary area, which is beneficial for uniform stress distribution and reducing stress concentration at individual triplex grain boundaries; at the same time, pure austenitic structure is directly obtained without subsequent solution treatment, avoiding grain growth during heat treatment. (2) For problem two, the preparation of materials with suppressed thermal phase transformation is completed through composition design, reducing the phase transformation temperature of copper-aluminum-manganese alloys and expanding their operating temperature range. At low temperatures, the critical slip stress of the material increases, while the critical phase transformation stress decreases, further suppressing the generation of plastic deformation and promoting more stable superelasticity. (3) For problem four, by designing the composition, in Cu... 71 Al 18 Mn 11 Adding Al and Mn elements further suppresses martensitic transformation and promotes austenite stabilization. Therefore, the reverse transformation process from martensite to austenite is easier, meaning the driving force for the reverse transformation is increased, promoting complete recovery of the hyperelasticity.

[0009] To address the problems of insufficient hyperelastic strain, narrow low-temperature operating temperature range, and susceptibility to plastic deformation in existing copper-aluminum-manganese alloys, this invention proposes to prepare micron-sized polycrystalline alloys with suppressed phase transformation through alloy composition design and laser powder bed melting technology. To further address the issues of low strain, low recovery rate, and narrow temperature range in copper-aluminum-manganese alloys prepared by traditional casting methods, an additive manufacturing method for wide-temperature-range hyperelastic polycrystalline copper-aluminum-manganese alloys is proposed, resulting in a significant improvement in material properties. Summary of the Invention

[0010] The purpose of this invention is to provide an additive manufacturing method for a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy, aiming to solve the technical problems of insufficient superelastic strain, narrow low-temperature working temperature range, and easy plastic deformation of polycrystalline materials in the prior art.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is: to provide an additive manufacturing method for a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy, comprising:

[0012] Step 1: Pre-treat the copper-aluminum-manganese raw materials to obtain pre-treated copper-aluminum-manganese raw materials;

[0013] Step 2: Weigh the required mass of pretreated copper-aluminum-manganese raw materials according to the fixed composition ratio to obtain the copper-aluminum-manganese raw materials with the correct composition ratio.

[0014] Step 3: The copper-aluminum-manganese raw materials with the specified composition are subjected to electric arc melting to obtain copper-aluminum-manganese alloy ingots;

[0015] Step 4: Atomize the copper-aluminum-manganese alloy ingot to obtain copper-aluminum-manganese alloy powder;

[0016] Step 5: 3D printing and in-situ secondary melting of copper-aluminum-manganese alloy powder are performed. After printing, copper-aluminum-manganese alloy samples are obtained by wire cutting.

[0017] Step 6: Perform stress-relief heat treatment on the copper-aluminum-manganese alloy sample to obtain polycrystalline copper-aluminum-manganese alloy.

[0018] Optionally, step 1 includes:

[0019] Step 1.1: Place the manganese raw material with a purity of 99-99.99% in a 10L volume of dilute nitric acid solution with a volume fraction of 2-3% and wash for 20-30 seconds to obtain the washed manganese raw material;

[0020] Step 1.2: Quickly place the cleaned manganese raw material into 20L of distilled water and sonicate for 3-5 minutes to obtain the sonicated manganese raw material;

[0021] Step 1.3: Place the ultrasonicated manganese raw material in a 10L solution of dilute nitric acid with a volume fraction of 1-2% and sonicate for 20-30 seconds to obtain a manganese raw material after secondary ultrasonication.

[0022] Step 1.4: Place the manganese raw material after the second ultrasonication in 20L of distilled water and sonicate for 3-5 minutes to obtain the manganese raw material after the third ultrasonication.

[0023] Step 1.5: Place the manganese raw material after three ultrasonic treatments in 10L of alcohol and sonicate for 3-5 minutes to obtain the manganese raw material after four ultrasonic treatments.

[0024] Step 1.6: Use a cold air blower to dry the manganese raw material after four ultrasonic treatments to obtain the pretreated manganese raw material;

[0025] Step 1.7: Place the aluminum raw material with a purity of 99-99.99% in 10L of alcohol and sonicate for 3-5 minutes to obtain the sonicated aluminum raw material. Use a cold air blower to dry the sonicated aluminum raw material to obtain the pretreated aluminum raw material.

[0026] Step 1.8: Place the copper raw material with a purity of 99-99.99% in 10L of alcohol and sonicate for 3-5 minutes to obtain the sonicated aluminum raw material. Use a cold air blower to dry the sonicated aluminum raw material to obtain the pretreated copper raw material.

[0027] Optionally, step 2 includes:

[0028] The fixed composition ratio of copper, aluminum and manganese raw materials is: copper 65-70 At%: aluminum 16-20 At%: manganese 11-15 At%;

[0029] The mass of the copper-aluminum-manganese raw material after the composition ratio is 30-60 kg.

[0030] Optionally, step 3 includes:

[0031] Manganese raw material is placed at the bottom, aluminum raw material in the middle, and copper raw material at the top for electric arc melting. During the melting process, 1-2% manganese and 1-2% aluminum by mass of the ingot are added.

[0032] Optionally, step 4 includes:

[0033] Step 4.1: Place the copper-aluminum-manganese alloy ingot in a high-pressure gas atomizing device;

[0034] Step 4.2: Argon gas is introduced into the high-pressure gas atomizing device for gas washing, and the high-pressure gas atomizing device is evacuated to 0.05-0.2 Pa to obtain the high-pressure gas atomizing device after evacuation;

[0035] Step 4.3: Heat the high-pressure gas atomizing device after vacuuming until the temperature reaches 1050-1150℃, and keep it at that temperature for 15-20 minutes to completely melt the copper-aluminum-manganese alloy ingot, and obtain the copper-aluminum-manganese alloy melt and the heated high-pressure gas atomizing device.

[0036] Step 4.4: Argon gas is introduced into the heated high-pressure gas atomizing device to make the internal gas pressure of the high-pressure gas atomizing device reach 8-10 MPa, thus obtaining the pressurized high-pressure gas atomizing device;

[0037] Step 4.5: The pressurized high-pressure gas atomizing device is heated a second time at a heating rate of 30-50K / min until the temperature of the high-pressure gas atomizing device reaches 1300-1350℃, and then held at that temperature for 3-5 minutes to obtain the high-pressure gas atomizing device after secondary heating.

[0038] Step 4.6: Control the flow rate of the copper-aluminum-manganese alloy melt to 3-6 kg / min, so that the copper-aluminum-manganese alloy melt flows towards the nozzle;

[0039] Step 4.7: After secondary heating, a hydrogen-argon mixed high-pressure gas with a pressure of 10-12 MPa and containing 3-6% hydrogen is introduced into the nozzle of the high-pressure gas atomizing device. The hydrogen-argon mixed high-pressure gas pushes the copper-aluminum-manganese alloy melt through uniformly distributed micropores to complete the atomization process of the copper-aluminum-manganese alloy melt and obtain micron-sized liquid spheres.

[0040] Step 4.8: Cool the micron-sized liquid spheres to obtain the initial copper-aluminum-manganese alloy powder;

[0041] Step 4.9: Use a vibrating sieve to sieve the initial copper-aluminum-manganese alloy powder to obtain copper-aluminum-manganese alloy powder with a particle size of 15-53μm and a normal particle size distribution.

[0042] Optionally, step 5 includes:

[0043] Step 5.1: Set the printing parameters of the LIM-X150A laser powder bed melting equipment to obtain the laser powder bed melting equipment after parameter adjustment;

[0044] Step 5.2: 3D printing of copper-aluminum-manganese alloy powder using a laser powder bed melting equipment with adjusted parameters;

[0045] Step 5.3: During the 3D printing process, after each layer of powder is laid and printed, the laser energy remains unchanged. A laser with a scanning rate of 3000-5000 mm / min is used to perform in-situ secondary melting along the previous printing path to obtain copper-aluminum-manganese alloy powder after a single 3D printing.

[0046] Step 5.4: Cool the copper-aluminum-manganese alloy powder after a single 3D printing by air for 10-15 seconds to obtain cooled copper-aluminum-manganese alloy powder.

[0047] Step 5.5: Perform the next powder-laying printing on the cooled copper-aluminum-manganese alloy powder;

[0048] Step 5.6: Repeat steps 5.6-5.5 until the copper-aluminum-manganese alloy powder completes the 3D printing process and obtains the initial copper-aluminum-manganese alloy sample.

[0049] Step 5.7: Air cool the initial copper-aluminum-manganese alloy sample and blow away the floating powder on the surface of the initial copper-aluminum-manganese alloy sample with an air gun. Use wire cutting to cut off the initial copper-aluminum-manganese alloy sample after blowing off the floating powder on the surface to obtain the cut initial copper-aluminum-manganese alloy sample.

[0050] Step 5.8: Place the cut initial copper-aluminum-manganese alloy sample in 100-200 mL of acetone and sonicate for 5-10 min to clean the oil stains from the initial copper-aluminum-manganese alloy sample after sonication, and obtain the initial copper-aluminum-manganese alloy sample after cleaning the oil stains.

[0051] Step 5.9: Use a cold air blower to dry the initial copper-aluminum-manganese alloy sample after it has been cleaned of oil, and obtain the copper-aluminum-manganese alloy sample.

[0052] Optionally, step 5.1 includes:

[0053] The printing parameters for the LIM-X150A laser powder bed melting equipment are as follows: Ar atmosphere, stainless steel substrate preheated to 150-200℃, 67° stripe printing strategy, laser spot size 70-90μm, laser energy 325-350W, laser scanning speed 1000-1500mm / min, scanning spacing 80-120μm, printing layer thickness 50μm, number of printing layers 150-250, and the thickness of the printed copper-aluminum-manganese alloy sample is 7.2-12.5mm.

[0054] Optionally, step 6 includes:

[0055] Step 6.1: Clean and dry the coarse quartz glass tube and the fine quartz glass tube to obtain the treated coarse quartz glass tube;

[0056] Step 6.2: Use #1000 grit sandpaper to grind away the surface oxide layer of the copper-aluminum-manganese alloy sample to obtain the polished copper-aluminum-manganese alloy sample;

[0057] Step 6.3: Place the polished copper-aluminum-manganese alloy sample into a coarse quartz glass tube, use an oxyhydrogen generator to heat and seal one end of the coarse quartz glass tube, and connect a fine quartz glass tube with an inner diameter of 4-6mm to the other end of the coarse quartz glass tube.

[0058] Step 6.4: Place 0.5-1g of titanium wire and 0.3-0.5g of manganese sheet into a thin quartz glass tube, and apply 3-5cm of vacuum grease to the narrow end of the thin quartz glass tube before connecting it to a rubber hose connected to a vacuum system.

[0059] Step 6.5: Turn on the vacuum system to evacuate the thin and thick quartz glass tubes;

[0060] Step 6.6: Use a flame generated by an oxyhydrogen generator at a temperature of 2500-3000℃ to heat the manganese sheet at a distance of 3-4cm until the other end of the thin glass tube is completely softened and melted, so that the copper-aluminum-manganese alloy sample is sealed in the thin quartz glass tube and the coarse quartz glass tube.

[0061] Step 6.7: Set the temperature inside the LC-101-3 forced-air drying oven to 200-220℃ and keep it at that temperature for 25-30 minutes. Place the sealed fine quartz glass tube and coarse quartz glass tube into the LC-101-3 forced-air drying oven for heat treatment to obtain heat-treated fine quartz glass tube and coarse quartz glass tube.

[0062] Step 6.8: Air cool the heat-treated fine quartz glass tube and coarse quartz glass tube to obtain cooled fine quartz glass tube and coarse quartz glass tube;

[0063] Step 6.9: Place the cooled fine quartz glass tube and the coarse quartz glass tube between two steel plates that are 10-15cm long, 4-6cm wide, and 4-7mm thick, and apply pressure to crush the cooled fine quartz glass tube and the coarse quartz glass tube to obtain a polycrystalline copper-aluminum-manganese alloy.

[0064] Optionally, step 6.1 includes:

[0065] Step 6.1.1: Place a coarse quartz glass tube with an inner diameter of 13-15 mm and a length of 20-30 mm and a quartz glass tube with an inner diameter of 3-4 mm and an outer diameter of 4-6 mm into a 1-2% HF acid aqueous solution and wash for 18-24 hours to obtain a pre-cleaned coarse quartz glass tube and a fine quartz glass tube.

[0066] Step 6.1.2: Use distilled water to wash the coarse quartz glass tube and the fine quartz glass tube after the initial cleaning, and seal both ends of the coarse quartz glass tube and the fine quartz glass tube with absorbent paper;

[0067] Step 6.1.3: Place the sealed coarse quartz glass tube and fine quartz glass tube into an LC-101-3 forced-air drying oven at a temperature of 40-60℃ and dry for 3-6 hours to obtain the processed coarse quartz glass tube and fine quartz glass tube.

[0068] Optionally, step 6.5 includes:

[0069] Step 6.5.1: Turn on the vacuum system and evacuate the thin and thick quartz glass tubes for 25-30 minutes. When the vacuum level in the thin and thick quartz glass tubes drops to ~10... -6 After Pa, the tubes are purged with high-purity argon gas at a pressure of 100 MPa and a purity of 99.999% to obtain fine and coarse quartz glass tubes after purging.

[0070] Step 6.5.2: Continue evacuating the fine and coarse quartz glass tubes after gas washing. When the vacuum level of the fine and coarse quartz glass tubes is lower than ~10... -6 After Pa, high-purity argon gas with a pressure of 0.1 MPa and a purity of 99.999% is returned to the tube, resulting in a fine quartz glass tube and a coarse quartz glass tube after vacuuming.

[0071] The beneficial effects of the additive manufacturing method and system for a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy provided by this invention are as follows: Compared with the prior art, this invention addresses the problems of grain coarsening caused by the need for high-temperature solution treatment in the preparation of copper-aluminum-manganese polycrystalline alloys by existing casting methods, which leads to insufficient superelastic strain, narrow working temperature range, easy plastic deformation, and poor cycle stability. By designing the composition and using laser additive manufacturing, this invention prepares a polycrystalline copper-aluminum-manganese alloy with controllable morphology, fine grains, uniform composition, large superelastic strain under favorable texture conditions, and complete reverse phase transformation without solution treatment, exhibiting excellent superelasticity. Attached Figure Description

[0072] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0073] Figure 1 A flowchart illustrating an additive manufacturing method for a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy, provided as an embodiment of the present invention.

[0074] Figure 2 The diagram shows the processed coarse quartz glass tube and fine quartz glass tube provided in the embodiments of the present invention.

[0075] Figure 3 This image shows a sample of copper, aluminum, and manganese prepared by selective laser melting, as provided in an embodiment of the present invention.

[0076] Figure 4 Backscattered electron (BSE) image of a polished cross section of a polycrystalline copper-aluminum-manganese alloy provided in an embodiment of the present invention under a scanning electron microscope.

[0077] Figure 5 Metallographic diagram of a cross-section of a polycrystalline copper-aluminum-manganese alloy in the forming direction, provided in an embodiment of the present invention.

[0078] Figure 6 The backscattered electron diffraction (EBSD) pattern of the polycrystalline copper-aluminum-manganese alloy forming surface provided in the embodiments of the present invention.

[0079] Figure 7 EBSD image of a polycrystalline copper-aluminum-manganese alloy side view provided in an embodiment of the present invention.

[0080] Figure 8 The XRD patterns of copper-aluminum-manganese alloy powder and printed polycrystalline copper-aluminum-manganese alloy samples provided in the embodiments of the present invention.

[0081] Figure 9The phase transition is tested by measuring the resistance-temperature curve of the critical stress versus temperature, which is provided in the embodiments of the present invention.

[0082] Figure 10 The superelastic properties of polycrystalline copper-aluminum-manganese alloy cut along the tensile direction at different temperatures are provided in the embodiments of the present invention.

[0083] Figure 11 The graph shows the trend of critical stress versus temperature for polycrystalline copper-aluminum-manganese alloys provided in this embodiment of the invention.

[0084] Figure 12 The superelastic residual strain of the polycrystalline copper-aluminum-manganese alloy provided in the embodiments of the present invention varies with temperature. Detailed Implementation

[0085] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0086] Please see Figure 1 The present invention will now describe an additive manufacturing method for a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy.

[0087] An additive manufacturing method for a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy includes:

[0088] Step 1: Pre-treat the copper-aluminum-manganese raw materials to obtain pre-treated copper-aluminum-manganese raw materials;

[0089] Furthermore, step 1 includes:

[0090] Step 1.1: Place the manganese raw material with a purity of 99-99.99% in a 10L volume of dilute nitric acid solution with a volume fraction of 2-3% and wash for 20-30 seconds to obtain the washed manganese raw material;

[0091] Step 1.2: Quickly place the cleaned manganese raw material into 20L of distilled water and sonicate for 3-5 minutes to obtain the sonicated manganese raw material;

[0092] Step 1.3: Place the ultrasonicated manganese raw material in a 10L solution of dilute nitric acid with a volume fraction of 1-2% and sonicate for 20-30 seconds to obtain a manganese raw material after secondary ultrasonication.

[0093] Step 1.4: Place the manganese raw material after the second ultrasonication in 20L of distilled water and sonicate for 3-5 minutes to obtain the manganese raw material after the third ultrasonication.

[0094] Step 1.5: Place the manganese raw material after three ultrasonic treatments in 10L of alcohol and sonicate for 3-5 minutes to obtain the manganese raw material after four ultrasonic treatments.

[0095] Step 1.6: Use a cold air blower to dry the manganese raw material after four ultrasonic treatments to obtain the pretreated manganese raw material;

[0096] Step 1.7: Place the aluminum raw material with a purity of 99-99.99% in 10L of alcohol and sonicate for 3-5 minutes to obtain the sonicated aluminum raw material. Use a cold air blower to dry the sonicated aluminum raw material to obtain the pretreated aluminum raw material.

[0097] Step 1.8: Place the copper raw material with a purity of 99-99.99% in 10L of alcohol and sonicate for 3-5 minutes to obtain the sonicated aluminum raw material. Use a cold air blower to dry the sonicated aluminum raw material to obtain the pretreated copper raw material.

[0098] Step 2: Weigh the required mass of pretreated copper-aluminum-manganese raw materials according to the fixed composition ratio to obtain the copper-aluminum-manganese raw materials with the correct composition ratio.

[0099] Furthermore, step 2 includes:

[0100] The fixed composition ratio of copper, aluminum and manganese raw materials is: copper 65-70 At%: aluminum 16-20 At%: manganese 11-15 At%;

[0101] The mass of the copper-aluminum-manganese raw material after the composition ratio is 30-60 kg.

[0102] Step 3: The copper-aluminum-manganese raw materials with the specified composition are subjected to electric arc melting to obtain copper-aluminum-manganese alloy ingots;

[0103] Furthermore, step 3 includes:

[0104] Manganese raw material is placed at the bottom, aluminum raw material in the middle, and copper raw material at the top for electric arc melting. During the melting process, 1-2% manganese and 1-2% aluminum by mass of the ingot are added.

[0105] Step 4: Atomize the copper-aluminum-manganese alloy ingot to obtain copper-aluminum-manganese alloy powder;

[0106] Furthermore, step 4 includes:

[0107] Step 4.1: Place the copper-aluminum-manganese alloy ingot in a high-pressure gas atomizing device;

[0108] Step 4.2: Argon gas is introduced into the high-pressure gas atomizing device for gas washing, and the high-pressure gas atomizing device is evacuated to 0.05-0.2 Pa to obtain the high-pressure gas atomizing device after evacuation;

[0109] Step 4.3: Heat the high-pressure gas atomizing device after vacuuming until the temperature reaches 1050-1150℃, and keep it at that temperature for 15-20 minutes to completely melt the copper-aluminum-manganese alloy ingot, and obtain the copper-aluminum-manganese alloy melt and the heated high-pressure gas atomizing device.

[0110] Step 4.4: Argon gas is introduced into the heated high-pressure gas atomizing device to make the internal gas pressure of the high-pressure gas atomizing device reach 8-10 MPa, thus obtaining the pressurized high-pressure gas atomizing device;

[0111] Step 4.5: The pressurized high-pressure gas atomizing device is heated a second time at a heating rate of 30-50K / min until the temperature of the high-pressure gas atomizing device reaches 1300-1350℃, and then held at that temperature for 3-5 minutes to obtain the high-pressure gas atomizing device after secondary heating.

[0112] Step 4.6: Control the flow rate of the copper-aluminum-manganese alloy melt to 3-6 kg / min, so that the copper-aluminum-manganese alloy melt flows towards the nozzle;

[0113] Step 4.7: After secondary heating, a hydrogen-argon mixed high-pressure gas with a pressure of 10-12 MPa and containing 3-6% hydrogen is introduced into the nozzle of the high-pressure gas atomizing device. The hydrogen-argon mixed high-pressure gas pushes the copper-aluminum-manganese alloy melt through uniformly distributed micropores to complete the atomization process of the copper-aluminum-manganese alloy melt and obtain micron-sized liquid spheres.

[0114] Step 4.8: Cool the micron-sized liquid spheres to obtain the initial copper-aluminum-manganese alloy powder;

[0115] Step 4.9: Use a vibrating sieve to sieve the initial copper-aluminum-manganese alloy powder to obtain copper-aluminum-manganese alloy powder with a particle size of 15-53μm and a normal particle size distribution.

[0116] Step 5: 3D printing and in-situ secondary melting of copper-aluminum-manganese alloy powder are performed. After printing, copper-aluminum-manganese alloy samples are obtained by wire cutting.

[0117] Furthermore, step 5 includes:

[0118] Step 5.1: Set the printing parameters of the LIM-X150A laser powder bed melting equipment to obtain the laser powder bed melting equipment after parameter adjustment;

[0119] Furthermore, step 5.1 includes:

[0120] The printing parameters for the LIM-X150A laser powder bed melting equipment are as follows: Ar atmosphere, stainless steel substrate preheated to 150-200℃, 67° stripe printing strategy, laser spot size 70-90μm, laser energy 325-350W, laser scanning speed 1000-1500mm / min, scanning spacing 80-120μm, printing layer thickness 50μm, number of printing layers 150-250, and the thickness of the printed copper-aluminum-manganese alloy sample is 7.2-12.5mm.

[0121] Step 5.2: 3D printing of copper-aluminum-manganese alloy powder using a laser powder bed melting equipment with adjusted parameters;

[0122] Step 5.3: During the 3D printing process, after each layer of powder is laid and printed, the laser energy remains unchanged. A laser with a scanning rate of 3000-5000 mm / min is used to perform in-situ secondary melting along the previous printing path to obtain copper-aluminum-manganese alloy powder after a single 3D printing.

[0123] Step 5.4: Cool the copper-aluminum-manganese alloy powder after a single 3D printing by air for 10-15 seconds to obtain cooled copper-aluminum-manganese alloy powder.

[0124] Step 5.5: Perform the next powder-laying printing on the cooled copper-aluminum-manganese alloy powder;

[0125] Step 5.6: Repeat steps 5.6-5.5 until the copper-aluminum-manganese alloy powder completes the 3D printing process and obtains the initial copper-aluminum-manganese alloy sample.

[0126] Step 5.7: Air cool the initial copper-aluminum-manganese alloy sample and blow away the floating powder on the surface of the initial copper-aluminum-manganese alloy sample with an air gun. Use wire cutting to cut off the initial copper-aluminum-manganese alloy sample after blowing off the floating powder on the surface to obtain the cut initial copper-aluminum-manganese alloy sample.

[0127] Step 5.8: Place the cut initial copper-aluminum-manganese alloy sample in 100-200 mL of acetone and sonicate for 5-10 min to clean the oil stains from the initial copper-aluminum-manganese alloy sample after sonication, and obtain the initial copper-aluminum-manganese alloy sample after cleaning the oil stains.

[0128] Step 5.9: Use a cold air blower to dry the initial copper-aluminum-manganese alloy sample after it has been cleaned of oil, and obtain the copper-aluminum-manganese alloy sample.

[0129] Step 6: Perform stress-relief heat treatment on the copper-aluminum-manganese alloy sample to obtain polycrystalline copper-aluminum-manganese alloy.

[0130] Furthermore, step 6 includes:

[0131] Step 6.1: Clean and dry the coarse quartz glass tube and the fine quartz glass tube to obtain the treated coarse quartz glass tube;

[0132] Furthermore, step 6.1 includes:

[0133] Step 6.1.1: Place a coarse quartz glass tube with an inner diameter of 13-15 mm and a length of 20-30 mm and a quartz glass tube with an inner diameter of 3-4 mm and an outer diameter of 4-6 mm into a 1-2% HF acid aqueous solution and wash for 18-24 hours to obtain a pre-cleaned coarse quartz glass tube and a fine quartz glass tube.

[0134] Step 6.1.2: Use distilled water to wash the coarse quartz glass tube and the fine quartz glass tube after the initial cleaning, and seal both ends of the coarse quartz glass tube and the fine quartz glass tube with absorbent paper;

[0135] Step 6.1.3: Place the sealed coarse quartz glass tube and fine quartz glass tube into an LC-101-3 forced-air drying oven at a temperature of 40-60℃ and dry for 3-6 hours to obtain the processed coarse quartz glass tube and fine quartz glass tube.

[0136] Step 6.2: Use #1000 grit sandpaper to grind away the surface oxide layer of the copper-aluminum-manganese alloy sample to obtain the polished copper-aluminum-manganese alloy sample;

[0137] Step 6.3: Place the polished copper-aluminum-manganese alloy sample into a coarse quartz glass tube, use an oxyhydrogen generator to heat and seal one end of the coarse quartz glass tube, and connect a fine quartz glass tube with an inner diameter of 4-6mm to the other end of the coarse quartz glass tube.

[0138] Step 6.4: Place 0.5-1g of titanium wire and 0.3-0.5g of manganese sheet into a thin quartz glass tube, and apply 3-5cm of vacuum grease to the narrow end of the thin quartz glass tube before connecting it to a rubber hose connected to a vacuum system.

[0139] Step 6.5: Turn on the vacuum system to evacuate the thin and thick quartz glass tubes;

[0140] Furthermore, step 6.5 includes:

[0141] Step 6.5.1: Turn on the vacuum system and evacuate the thin and thick quartz glass tubes for 25-30 minutes. When the vacuum level in the thin and thick quartz glass tubes drops to ~10... -6 After Pa, the tubes are purged with high-purity argon gas at a pressure of 100 MPa and a purity of 99.999% to obtain fine and coarse quartz glass tubes after purging.

[0142] Step 6.5.2: Continue evacuating the fine and coarse quartz glass tubes after gas washing. When the vacuum level of the fine and coarse quartz glass tubes is lower than ~10... -6 After Pa, high-purity argon gas with a pressure of 0.1 MPa and a purity of 99.999% is returned to the tube, resulting in a fine quartz glass tube and a coarse quartz glass tube after vacuuming.

[0143] Step 6.6: Use a flame generated by an oxyhydrogen generator at a temperature of 2500-3000℃ to heat the manganese sheet at a distance of 3-4cm until the other end of the thin glass tube is completely softened and melted, so that the copper-aluminum-manganese alloy sample is sealed in the thin quartz glass tube and the coarse quartz glass tube.

[0144] Step 6.7: Set the temperature inside the LC-101-3 forced-air drying oven to 200-220℃ and keep it at that temperature for 25-30 minutes. Place the sealed fine quartz glass tube and coarse quartz glass tube into the LC-101-3 forced-air drying oven for heat treatment to obtain heat-treated fine quartz glass tube and coarse quartz glass tube.

[0145] Step 6.8: Air cool the heat-treated fine quartz glass tube and coarse quartz glass tube to obtain cooled fine quartz glass tube and coarse quartz glass tube;

[0146] Step 6.9: Place the cooled fine quartz glass tube and the coarse quartz glass tube between two steel plates that are 10-15cm long, 4-6cm wide, and 4-7mm thick, and apply pressure to crush the cooled fine quartz glass tube and the coarse quartz glass tube to obtain a polycrystalline copper-aluminum-manganese alloy.

[0147] Example

[0148] Smelting of copper-aluminum-manganese alloy ingots: The raw materials used are high-purity copper, aluminum, and manganese metals, all with a purity of 99-99.99%. The manganese raw material needs to be cleaned to remove the surface oxide layer and reduce the introduction of impurities. The specific steps are as follows: First, clean in ~10L of 2-3% (v / v) dilute nitric acid solution for 20-30 seconds, then quickly transfer to ~20L of distilled water and sonicate for 3-5 minutes. Next, sonicate in ~10L of 1-2% (v / v) dilute nitric acid solution for 20-30 seconds, then sonicate in ~20L of distilled water for 3-5 minutes. Finally, sonicate in 10L of alcohol for 3-5 minutes, and then dry with a cold air blower. Copper and aluminum are sonicated in 10L of alcohol for 3-5 minutes and then dried with a cold air blower.

[0149] Alloy ingots were prepared using electric arc melting, according to Cu... 69.14 Al 18.74 Mn 12.12(at.%) Weigh the alloy raw materials, with a total mass of 30-60 kg. During the smelting process, place the volatile manganese at the bottom, aluminum in the middle, and copper at the top to reduce the volatilization of elements during smelting. At the same time, add an additional 1-2% manganese and 1-2% aluminum by mass of the ingot to compensate for volatilization loss.

[0150] Atomization preparation of alloy powder: A copper-aluminum-manganese alloy ingot is placed in a high-pressure gas atomization powder-making device. First, the ingot is purged with argon gas 2-4 times, and the vacuum is reduced to 0.05-0.2 Pa. The mixture is then heated to 1050-1150℃ and held for 15-20 minutes to completely melt the material. Argon gas is then introduced to increase the gas pressure to 8-10 MPa, thereby reducing the volatilization of aluminum and manganese. Then, the mixture is rapidly heated to 1300-1350℃ at a heating rate of 30-50 K / min and held for 3-5 minutes to reduce the residence time at high temperatures and minimize the volatilization loss of aluminum and manganese in the material. To suppress oxidation, improve atomization efficiency, and control the particle size of the prepared powder, a high-pressure hydrogen-argon mixture containing 3-6% hydrogen at 10-12 MPa is introduced, and the melt flow rate is controlled at 3-6 kg / min. The high-pressure gas is then passed through uniformly distributed micropores to form a high-speed gas flow, which atomizes the alloy melt to obtain micron-sized liquid spheres. After cooling, copper-aluminum-manganese alloy powder can be obtained.

[0151] The powder was sieved using a vibrating sieve to obtain copper-aluminum-manganese alloy powder with a particle size of 15-53 μm and a normal particle size distribution.

[0152] 3D printing of copper-aluminum-manganese alloy powder: Printing was performed using a LIM-X150A laser powder bed fusion machine. Printing parameters were as follows: Ar atmosphere, stainless steel substrate; substrate preheating temperature of 150-200℃ to suppress cracking and reduce internal stress; laser spot size of 70-90μm to control the volume and morphology of the laser-treated layer; energy conforming to a Gaussian normal distribution; and a 67° stripe printing strategy. Due to the high reflectivity of copper alloys, the printing energy used for ordinary alloys was insufficient to completely melt the material. To ensure molding quality, a laser energy of 325-350W and a scanning speed of 1000-1500mm / min were selected to avoid decreased molding accuracy due to excessive energy density. A layer thickness of 50μm was chosen to reduce molding time, and the scanning spacing of 80-120μm was controlled to ensure tight bonding between the molten pools. Sample thickness ranged from 7.2-12.5mm (150-250 layers printed in total).

[0153] During the printing process, after each layer is printed, the laser energy remains constant, and an additional laser scan is performed along the original printing path at a scanning rate of 3000-5000 mm / min. The purpose is to reduce the heat-affected zone on the material surface, creating new smaller molten pools within the original large molten pool. Because the molten pool boundaries cool more rapidly, finer grains are more easily formed, thus increasing the content of fine-grained structures. The material is then cooled by air for 10-15 seconds to stabilize the surface temperature before the next layer of powder is printed. This method avoids phase transitions and grain growth caused by subsequent laser heat input, increases the fine-grained region within the molten pool, and yields small-sized grains. Furthermore, it reduces printing internal stress, preventing internal cracks in the sample.

[0154] After printing, the sample is air-cooled, the surface powder is blown off with an air gun, and the sample is cut off using wire cutting.

[0155] Soak the cut copper-aluminum-manganese alloy sample in acetone for 5-10 minutes to remove oil stains, and then dry it with a cold air blower.

[0156] Stress-relieving heat treatment of copper-aluminum-manganese alloy: Prepare coarse quartz glass tubes with an inner diameter of 13-15mm and a length of 20-30mm and fine quartz glass tubes with an inner diameter of 3-4mm and an outer diameter of 4-6mm. Soak them in a 1-2% HF acid aqueous solution for 18-24 hours. After that, wash the glass tubes with distilled water. Seal both ends of the glass tubes with absorbent paper to prevent dust from falling in. Then put them into an LC-101-3 forced-air drying oven for drying at a temperature of 40-60℃ for 3-6 hours.

[0157] The cut copper-aluminum-manganese alloy sample is ground to remove the surface oxide layer using #1000 sandpaper, and then placed into a coarse quartz glass tube with an inner diameter of 13-15mm that is open at both ends. One end is sealed with a flame generated by an oxyhydrogen generator, and the other end is connected to a fine quartz glass tube with an inner diameter of 4-6mm, dividing the tube into two parts. 0.5-1g of titanium wire and 0.3-0.5g of manganese sheet are placed in the other part to inhibit oxidation and element volatilization during the heat treatment process.

[0158] according to Figure 2 As shown, after applying 3-5cm of vacuum grease to the surface of the treated fine quartz glass tube, connect it to the rubber hose connected to the vacuum system and tighten it with a retaining ring to prevent leakage. Turn on the vacuum system and evacuate for 25-30 minutes. When the vacuum level inside the glass tube drops to ~10... -6 After Pa, refill with 100 MPa of 99.999% high-purity argon gas, purge once, and continue evacuation until the vacuum level is below ~10. -6After passing through the pressure (Pa), the tube is refilled with 0.1 MPa of 99.999% high-purity argon. Then, using a flame generated by an oxyhydrogen generator, heat is applied to the middle section of the thin quartz tube, 3-4 cm away from the manganese plate, until the glass tube completely softens and melts, sealing the alloy sample inside the glass tube. This treatment method can suppress the oxidation of the alloy and the volatilization of manganese during heat treatment.

[0159] The sealed quartz tube containing the copper-aluminum-manganese alloy sample was placed in an LC-101-3 forced-air drying oven at 200-220℃ for 25-30 minutes. After heat treatment, it was removed and air-cooled. The cooled glass was then placed between two steel plates 10-15cm long, 4-6cm wide, and 4-7mm thick, and pressure was applied to crush the glass, yielding the heat-treated copper-aluminum-manganese alloy block. This operation reduces internal stress and stabilizes martensitic phase transformation behavior while maintaining the phase structure and suppressing grain growth.

[0160] according to Figure 3 As shown, the present invention uses selective laser melting to prepare copper-aluminum-manganese alloy bulk materials with metallic luster and good dimensional accuracy. Furthermore, this method can be used to prepare copper-aluminum-manganese alloys with various complex structures.

[0161] according to Figure 4 As shown, Figure 4 The image shows a backscattered electron (BSE) image of a polished cross section of a typical prepared sample under a scanning electron microscope. It can be seen that the sample has high density under the preparation process conditions adopted in this invention, and there are no cracks, defects or precipitates inside the sample, which proves its good formability.

[0162] according to Figure 5 As shown, Figure 5 Metallographic images of the prepared sample along the forming direction ( / / BD) show significant molten pool overlap during the fabrication process. Backscattered electron diffraction (EBSD) was performed on the forming surface (⊥BD) of the prepared sample to analyze its grain size and texture.

[0163] according to Figure 6 As shown, this indicates the formation of fine grains within the material, with an average grain size of 12.3 μm. Its inverse pole figure indicates that the prepared material possesses strong [grain density] along the forming direction. <001> A Texture.

[0164] according to Figure 7 As shown, Figure 7The EBSD orientation diagram of the prepared sample along the forming direction ( / / BD) shows that the material as a whole forms a large columnar crystal structure along the BD direction, with an average base size of 12.75 μm and an average length of over 100 μm. Furthermore, fine-grained regions with a grain size of approximately 5 μm are formed at the bottom of some molten pools, creating a coarse-fine-coarse bimodal structure.

[0165] according to Figure 8 As shown, Figure 8 XRD analysis of the sample revealed distinct L21 single-phase characteristics, and the backscattering pattern confirmed the absence of significant component segregation. The material was then subjected to electrical resistance testing.

[0166] according to Figure 9 As shown, the material M s M f A s A f The point temperatures were 178K, 142K, 165K, and 201K, respectively. Based on the above, it has been proven that the material is in the L21 austenitic state at room temperature, and the phase transformation of the material can be seen to be successfully suppressed to below -73℃.

[0167] according to Figure 10 As shown, this invention cuts tensile samples along the BD direction and performs tensile stress-strain tests on the alloy at different temperatures. It can be seen that along the BD direction, the material exhibits good hyperelasticity (hyperelastic strain can reach 9%) during loading and unloading under tensile conditions. The stress-induced martensitic critical phase transformation stress is low (164-226 MPa) and the strain reversibility is good. This large hyperelastic strain originates from the material's strong texture behavior. The martensitic phase transformation of copper-aluminum-manganese alloys is a transition from the L21 structure to the 18R structure, wherein... <001> The direction exhibits the greatest strain, with phase transformation strain reaching over 9%. However, the lattice distortion caused by phase transformation in single-crystal materials is excessive, and the presence of Lüders bands indicates that the material cannot undergo a complete phase transformation. Therefore, this fine-grained... <001> A Textured samples can balance the strain distribution in the shear direction, thereby increasing the phase transformation percentage of the material and obtaining a higher strain level. Furthermore, the critical phase transformation stress of stress-induced martensite in this alloy changes little with temperature.

[0168] according to Figure 11 As shown, this invention analyzes the trend of critical phase transformation stress with temperature. It can be seen that the data basically conforms to the Clausius-Clapeyron equation relationship. The rate of change of critical phase transformation stress with temperature is low, with a slope of only 0.42 (greater than 2 for coarse-grained CuAlMn alloy and 10 for NiTi single crystal), indicating that this material has good wide-temperature stability.

[0169] according to Figure 12 As shown, this invention statistically analyzed the variation of superelastic residual strain with temperature. The residual strain is significant at low temperatures, gradually decreasing and remaining below 1% as the temperature rises to -60℃. Considering the surface temperature of Mars is approximately -70℃ to 40℃, it can be seen that this material exhibits good superelasticity within the corresponding temperature range. Analysis reveals that the low C-C curve slope of this material is due to its fine-grained structure and rapid solidification. The formation of the fine-grained region indicates rapid solidification in this area, unaffected by the heat treatment during subsequent printing. These fine grains hinder martensitic phase transformation, causing the phase transformation behavior to shift towards a continuous phase transformation. Therefore, the resistance of temperature to phase transformation manifests as a continuous effect with loading, i.e., the increase in the slope of the stress-strain curve after the phase transformation begins during loading, thereby reducing the effect of temperature on the critical phase transformation stress.

[0170] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of additive manufacturing of a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy, characterized by, include: Step 1: Pre-treat the copper-aluminum-manganese raw materials to obtain pre-treated copper-aluminum-manganese raw materials; Step 2: Weigh the required mass of pretreated copper-aluminum-manganese raw materials according to the fixed composition ratio to obtain the copper-aluminum-manganese raw materials with the correct composition ratio. The fixed composition ratio of copper, aluminum, and manganese raw materials is: copper 65-70 At% : aluminum 16-20 At% : manganese 11-15 At% ; The mass of the copper-aluminum-manganese raw material after the composition ratio is 30-60 kg; Step 3: The copper-aluminum-manganese raw material with the specified composition ratio is subjected to electric arc melting to obtain a copper-aluminum-manganese alloy ingot; Step 3 includes: Manganese raw material is placed at the bottom, aluminum raw material in the middle, and copper raw material at the top for electric arc melting, and 1-2% manganese and 1-2% aluminum by mass of ingot are added during the melting process; Step 4: Atomize the copper-aluminum-manganese alloy ingot to obtain copper-aluminum-manganese alloy powder; Step 5: Perform 3D printing and in-situ secondary melting on the copper-aluminum-manganese alloy powder, and obtain copper-aluminum-manganese alloy samples by wire cutting after printing is completed; Step 5 includes: Step 5.1: Set the printing parameters of the LIM-X150A laser powder bed melting equipment to obtain the laser powder bed melting equipment after parameter adjustment; Step 5.1 includes: The printing parameters for the LIM-X150A laser powder bed melting equipment are as follows: Ar atmosphere, stainless steel substrate preheated to 150-200℃, 67° stripe printing strategy, laser spot size 70-90μm, laser energy 325-350W, laser scanning speed 1000-1500mm / min, scanning spacing 80-120μm, printing layer thickness 50μm, number of printing layers 150-250, and the thickness of the printed copper-aluminum-manganese alloy sample is 7.2-12.5mm. Step 5.2: 3D print the copper-aluminum-manganese alloy powder using a laser powder bed melting equipment with the parameters adjusted as described above; Step 5.3: During the 3D printing process, after each layer of powder is laid and printed, the laser energy remains unchanged. A laser with a scanning rate of 3000-5000 mm / min is used to perform in-situ secondary melting along the previous printing path to obtain a copper-aluminum-manganese alloy after a single 3D printing. Step 5.4: Cool the copper-aluminum-manganese alloy after the single 3D printing by air for 10-15 seconds to obtain the cooled copper-aluminum-manganese alloy. Step 5.5: Perform the next powder-laying printing on the cooled copper-aluminum-manganese alloy; Step 5.6: Repeat steps 5.2-5.5 until the copper-aluminum-manganese alloy powder completes the 3D printing process and obtains the initial copper-aluminum-manganese alloy sample; Step 5.7: Air-cool the initial copper-aluminum-manganese alloy sample and blow away the floating powder on the surface of the initial copper-aluminum-manganese alloy sample with an air gun. Use wire cutting to cut off the initial copper-aluminum-manganese alloy sample after blowing off the floating powder on the surface to obtain the cut initial copper-aluminum-manganese alloy sample. Step 5.8: Place the cut initial copper-aluminum-manganese alloy sample in 100-200 mL of acetone and sonicate for 5-10 min. Then wash off the oil stains from the initial copper-aluminum-manganese alloy sample after sonication to obtain the initial copper-aluminum-manganese alloy sample after cleaning off the oil stains. Step 5.9: Use a cold air blower to dry the initial copper-aluminum-manganese alloy sample after it has been cleaned of oil, to obtain a copper-aluminum-manganese alloy sample; Step 6: Perform stress-relief heat treatment on the copper-aluminum-manganese alloy sample to obtain a polycrystalline copper-aluminum-manganese alloy.

2. The additive manufacturing method for a wide-temperature-range superelastic polycrystalline copper-aluminum-manganese alloy according to claim 1, characterized in that, Step 1: Pre-treating the copper-aluminum-manganese raw materials to obtain pre-treated copper-aluminum-manganese raw materials, including: Step 1.1: Place the manganese raw material with a purity of 99-99.99% in a 10L volume of dilute nitric acid solution with a volume fraction of 2-3% and wash for 20-30 seconds to obtain the washed manganese raw material; Step 1.2: Quickly place the cleaned manganese raw material into 20L of distilled water and sonicate for 3-5 minutes to obtain the sonicated manganese raw material; Step 1.3: Place the ultrasonicated manganese raw material in a 10L volume of dilute nitric acid solution with a volume fraction of 1-2% and sonicate for 20-30 seconds to obtain a manganese raw material after secondary sonication. Step 1.4: Place the manganese raw material after the second ultrasonication in 20L of distilled water and ultrasonicate for 3-5 minutes to obtain the manganese raw material after the third ultrasonication. Step 1.5: Place the manganese raw material after three ultrasonic treatments in 10L of alcohol and ultrasonicate for 3-5 minutes to obtain manganese raw material after four ultrasonic treatments. Step 1.6: Use a cold air blower to dry the manganese raw material after the four ultrasonic treatments to obtain the pretreated manganese raw material; Step 1.7: Place aluminum raw material with a purity of 99-99.99% in 10L of alcohol and sonicate for 3-5 minutes to obtain ultrasonicated aluminum raw material. Use a cold air blower to dry the ultrasonicated aluminum raw material to obtain pretreated aluminum raw material. Step 1.8: Place the copper raw material with a purity of 99-99.99% in 10L of alcohol and sonicate for 3-5 minutes to obtain the sonicated copper raw material. Use a cold air blower to dry the sonicated copper raw material to obtain the pretreated copper raw material.

3. A method of additive manufacturing of a wide temperature range super-elastic polycrystalline copper-aluminum-manganese alloy according to claim 1, characterized in that, Step 4: Atomize the copper-aluminum-manganese alloy ingot to obtain copper-aluminum-manganese alloy powder, including: Step 4.1: Place the copper-aluminum-manganese alloy ingot in a high-pressure gas atomizing device; Step 4.2: Argon gas is introduced into the high-pressure gas atomizing device for gas washing, and the high-pressure gas atomizing device is evacuated to 0.05-0.2 Pa to obtain the high-pressure gas atomizing device after evacuation; Step 4.3: Heat the high-pressure gas atomizing device after vacuuming until the temperature reaches 1050-1150℃, and keep it at that temperature for 15-20 minutes to completely melt the copper-aluminum-manganese alloy ingot, thereby obtaining the copper-aluminum-manganese alloy melt and the heated high-pressure gas atomizing device. Step 4.4: Argon gas is introduced into the heated high-pressure gas atomizing device to make the gas pressure inside the high-pressure gas atomizing device reach 8-10 MPa, thus obtaining the pressurized high-pressure gas atomizing device; Step 4.5: The pressurized high-pressure gas atomizing device is heated a second time at a heating rate of 30-50K / min until the temperature of the high-pressure gas atomizing device reaches 1300-1350℃, and then kept at that temperature for 3-5 minutes to obtain the high-pressure gas atomizing device after secondary heating. Step 4.6: Control the flow rate of the copper-aluminum-manganese alloy melt to 3-6 kg / min, so that the copper-aluminum-manganese alloy melt flows towards the nozzle; Step 4.7: A hydrogen-argon mixed high-pressure gas with a pressure of 10-12 MPa and containing 3-6% hydrogen is introduced into the nozzle of the high-pressure gas atomizing device after secondary heating. The hydrogen-argon mixed high-pressure gas pushes the copper-aluminum-manganese alloy melt through uniformly distributed micropores to complete the atomization process of the copper-aluminum-manganese alloy melt and obtain micron-sized liquid spheres. Step 4.8: Cool the micron-sized liquid spheres to obtain initial copper-aluminum-manganese alloy powder; Step 4.9: Use a vibrating sieve to sieve the initial copper-aluminum-manganese alloy powder to obtain copper-aluminum-manganese alloy powder with a particle size of 15-53 μm and a normal particle size distribution.

4. The method of additive manufacturing of a wide temperature range super-elastic polycrystalline copper-aluminum-manganese alloy according to claim 1, wherein, Step 6: Performing stress-relief heat treatment on the copper-aluminum-manganese alloy sample to obtain a polycrystalline copper-aluminum-manganese alloy, including: Step 6.1: Clean and dry the coarse quartz glass tube and the fine quartz glass tube to obtain the treated coarse quartz glass tube; Step 6.2: Use #1000 grit sandpaper to grind away the surface oxide layer of the copper-aluminum-manganese alloy sample to obtain the polished copper-aluminum-manganese alloy sample; Step 6.3: The polished copper-aluminum-manganese alloy sample is placed into a coarse quartz glass tube. One end of the coarse quartz glass tube is heated and sealed using a hydrogen-oxygen generator. A fine quartz glass tube with an inner diameter of 4-6 mm is connected to the other end of the coarse quartz glass tube. Step 6.4: Place 0.5-1g of titanium wire and 0.3-0.5g of manganese sheet into the fine quartz glass tube, and apply 3-5cm of vacuum grease to the narrow end of the fine quartz glass tube before connecting it to a rubber hose connected to a vacuum system. Step 6.5: Open the vacuum system to evacuate the thin quartz glass tube and the coarse quartz glass tube; Step 6.6: Use a flame generated by an oxyhydrogen generator at a temperature of 2500-3000℃ to heat the manganese sheet at a distance of 3-4cm until the other end of the thin quartz glass tube is completely softened and melted, so that the copper-aluminum-manganese alloy sample is sealed in the thin quartz glass tube and the coarse quartz glass tube. Step 6.7: Set the temperature inside the LC-101-3 forced-air drying oven to 200-220℃ and keep it at that temperature for 25-30 minutes. Place the sealed fine quartz glass tube and coarse quartz glass tube into the LC-101-3 forced-air drying oven for heat treatment to obtain heat-treated fine quartz glass tube and coarse quartz glass tube. Step 6.8: The heat-treated fine quartz glass tube and coarse quartz glass tube are air-cooled to obtain cooled fine quartz glass tube and coarse quartz glass tube. Step 6.9: Place the cooled fine quartz glass tube and coarse quartz glass tube between two steel plates that are 10-15cm long, 4-6cm wide, and 4-7mm thick, and apply pressure to crush the cooled fine quartz glass tube and coarse quartz glass tube to obtain a polycrystalline copper-aluminum-manganese alloy.

5. A method of additive manufacturing of a wide temperature range super-elastic polycrystalline copper-aluminum-manganese alloy according to claim 4, characterized in that, Step 6.1: Cleaning and drying the coarse and fine quartz glass tubes to obtain the treated coarse quartz glass tube, comprising: Step 6.1.1: Place a coarse quartz glass tube with an inner diameter of 13-15 mm and a length of 20-30 mm and a quartz glass tube with an inner diameter of 3-4 mm and an outer diameter of 4-6 mm into a 1-2% HF acid aqueous solution and wash for 18-24 hours to obtain a pre-cleaned coarse quartz glass tube and a fine quartz glass tube. Step 6.1.2: Wash the pre-cleaned coarse quartz glass tube and fine quartz glass tube with distilled water and seal both ends of the coarse quartz glass tube and fine quartz glass tube with absorbent paper; Step 6.1.3: Place the sealed coarse quartz glass tube and fine quartz glass tube into an LC-101-3 forced-air drying oven at a temperature of 40-60℃ and dry for 3-6 hours to obtain the processed coarse quartz glass tube and fine quartz glass tube.

6. A method of additive manufacturing of a wide temperature range super-elastic polycrystalline copper-aluminum-manganese alloy according to claim 4, characterized in that, Step 6.5: Vacuuming the thin and thick quartz glass tubes by opening the vacuum system, including: Step 6.5.1: Turn on the vacuum system to evacuate the thin and thick quartz glass tubes for 25-30 minutes. When the vacuum level of the thin and thick quartz glass tubes drops to 10... -6 After Pa, the tubes are purged with high-purity argon gas at a pressure of 0.1 MPa and a purity of 99.999% to obtain fine and coarse quartz glass tubes after purging. Step 6.5.2: Continue to evacuate the fine and coarse quartz glass tubes after gas washing. When the vacuum level of the fine and coarse quartz glass tubes is lower than 10... -6 After Pa, high-purity argon gas with a pressure of 0.1 MPa and a purity of 99.999% is returned to the tube, resulting in a fine quartz glass tube and a coarse quartz glass tube after vacuuming.

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