A method for enhancing the toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder

Abstract

The patent discloses a method for enhancing the toughness of aluminum-lithium alloy welding wire based on doping high-entropy alloy powder, which improves the toughness of aluminum-lithium alloy welding wire and welding seam by doping high-entropy alloy powder. First, according to the performance requirements, the type and content of high-entropy alloy powder are set based on the first principle. Then, the correlation and prediction model of "welding wire composition-process parameter-toughness" is established based on machine learning to generate a high-toughness welding wire composition design space suitable for aluminum-lithium alloy welding. Finally, the type and content of high-entropy alloy powder added are optimized with service requirements as the screening condition. The preferred high-entropy alloy powder is uniformly dispersed in the welding wire. During welding, the powder particles form a weld seam with the melting of the welding wire, and the powder particles are uniformly dispersed in the weld seam as a strengthening phase, thereby improving the toughness of the weld seam. The method for enhancing the toughness of aluminum-lithium alloy welding wire based on doping high-entropy alloy powder provides a reliable solution for improving the quality of aluminum-lithium alloy welding.

Description

[0001] Zhan Xiaohong, Liu Ruizu, Wang Jianfeng, Li Yue Technical Field

[0002] This invention relates to the field of welding materials technology in materials processing engineering, and mainly to a method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder. Background Technology

[0003] Aluminum-lithium alloys (ALLI) are widely used in critical aerospace structural components due to their excellent comprehensive properties, including low density, high specific strength and stiffness, high elastic modulus, low fatigue crack propagation rate, good low-temperature performance, good corrosion resistance, and outstanding superplastic formability. ALI has been applied to critical structural components such as the payload adapter of the Karshid missile and LMSC's Titan launch vehicle, structural components of the Buran space shuttle, most structural materials of China's C919 large passenger aircraft, and the external storage tanks of the Endeavour space shuttle.

[0004] Laser welding is an advanced processing technology widely used in key structural components in the aerospace manufacturing field. It has advantages such as low heat input, high welding speed, high welding precision, strong adaptability, and good beam controllability. Although aluminum-lithium alloys have good overall performance, the lithium element is easily evaporated and oxidized during the welding process due to the influence of welding heat input. This leads to significant changes in the microstructure, resulting in problems such as numerous weld pores and a high tendency for welding hot cracking. Furthermore, the welding wire is prone to breakage during preparation, resulting in low production efficiency, unsatisfactory mechanical properties of the prepared welding wire, and poor weld joint performance.

[0005] High-entropy alloy powder possesses advantages such as high strength, high hardness, excellent wear resistance, and good interfacial wetting with aluminum-lithium alloys. Therefore, doping high-entropy alloy powder into aluminum-lithium alloy welding wire has great potential. High-entropy alloy powder can be dispersed in the aluminum-lithium alloy matrix, hindering grain boundary migration and achieving dispersion strengthening and grain refinement strengthening, thereby improving the strength and toughness of the welding wire and weld. Summary of the Invention

[0006] The technical problem this invention aims to solve is to overcome the issues of easy breakage and poor weld joint strength and toughness during the drawing process of aluminum-lithium alloy welding wires. A method is proposed to improve the strength and toughness of aluminum-lithium alloy welding wires by doping them with high-entropy alloy powder during wire drawing. A compositional design space suitable for improving the strength and toughness of aluminum-lithium alloys is generated based on service requirements. The interaction between the high-entropy alloy powder and the aluminum-lithium alloy produces dispersion strengthening and grain refinement, thereby improving the strength and toughness of the aluminum-lithium alloy.

[0007] This invention is achieved through the following technical solution:

[0008] A method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder is characterized by the high-entropy alloy powder being dispersed in the aluminum-lithium alloy matrix, hindering grain boundary migration, and achieving dispersion strengthening and grain refinement strengthening, thereby improving the strength and toughness of the welding wire and weld. The screening process for the optimal welding wire composition includes the following steps:

[0009] A method for designing the composition of reinforced aluminum-lithium alloy welding wire doped with high-entropy alloy powder includes the following steps:

[0010] (1) Welding wire composition design: Based on performance requirements and first principles, the type and content of high-entropy alloy powder that helps improve the strength and toughness of aluminum-lithium alloy are set. The weight percentage of each component of aluminum-lithium alloy welding wire is: Li 2.1~2.7%, Cu 1.4~1.6%, Mg 1.4~1.6%, high-entropy alloy powder 0.3~0.4%, and the remainder is Al;

[0011] (2) Establishment of composition design space: Based on machine learning, a correlation model and prediction model of “welding wire composition-process parameters-strength and toughness” are generated, a database is established, and a composition design space suitable for improving the strength and toughness of aluminum-lithium alloy is generated.

[0012] (3) Prediction of welding wire performance: Based on the established spatial database of welding wire composition design, the type and grain size of precipitated phases are calculated according to the type and composition of high-entropy alloy powder, and the strength and toughness of welding wire and weld are predicted to achieve synergistic improvement of strength and toughness of aluminum-lithium alloy welding wire.

[0013] (4) Optimal solution for welding wire screening and preparation: Based on the service requirements, multiple iterations of screening were carried out to complete the optimal solution screening of the composition of the reinforced aluminum-lithium alloy welding wire doped with high-entropy alloy powder, and a high-strength and high-toughness aluminum-lithium alloy welding wire doped with high-entropy alloy powder was prepared.

[0014] Furthermore, the high-entropy alloy powders that help improve the strength and toughness of aluminum-lithium alloys are set as AlxCoCrFeNi, FeNiCoCrMn, and TiZrHfNbTa. The characteristic is that the selected high-entropy alloy powders all have strong strength or toughness, and all have an interaction mechanism with Al, which can effectively hinder the movement of grain boundaries, thereby achieving the purpose of improving the strength and toughness of welding wire and weld.

[0015] Furthermore, the established correlation model and prediction model of "welding wire composition-process parameters-strength and toughness" are characterized by using resolution to solve the correlation degree between welding wire composition, process parameters, and strength and toughness and establishing a mathematical model, and finally predicting the changes in the strength and toughness of aluminum-lithium alloy based on the residual test method.

[0016] Furthermore, based on service requirements and databases, the welding wire composition was iteratively screened multiple times. The interaction mechanism, precipitated phase volume, and mechanical properties of high-entropy alloy powder and aluminum-lithium alloy were screened to identify the optimal type and ratio of high-entropy alloy powder suitable for improving the strength and toughness of aluminum-lithium alloy welding wire.

[0017] Furthermore, based on the optimal solution of the selected welding wire composition, a solid powder homogenizer is used to uniformly mix high-entropy alloy powder and aluminum-lithium alloy powder. The high-entropy alloy powder forms uniform reinforcing phase particles in the aluminum-lithium alloy matrix and exists as a strengthening phase in the weld.

[0018] Based on this, the preparation process of reinforced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder includes the following steps:

[0019] (1) The high-entropy alloy powder and aluminum-lithium alloy raw materials in the specified proportions are smelted in a vacuum induction furnace at a temperature of 800-830℃.

[0020] (2) After removing impurities from the surface and both ends of the ingot, the alloy wire rod is continuously extruded at 500-550℃.

[0021] (3) After the alloy wire rod is coarsely, medium and finely drawn, it is homogenized and annealed in the middle, and then scraped and cleaned to obtain the welding wire.

[0022] Furthermore, during the preparation process, the argon flow rate during vacuum melting is 8–10 ml / s, and the purification vacuum degree is 1 × 10⁻⁶. -3 ~2×10 -3 Pa; after fine drawing, it is made into a reinforced aluminum-lithium alloy high-toughness welding wire with a diameter of 1.2mm.

[0023] The beneficial effects of this invention are reflected in the following aspects:

[0024] This invention provides a method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder. Based on the interaction mechanism between high-entropy alloy powder and Al element, and the strengthening effect of precipitated phases, suitable high-entropy alloy powders and their content for improving the strength and toughness of aluminum-lithium alloy welding wire are selected. The high-entropy alloy powder particles are dispersed in the aluminum-lithium alloy matrix, forming numerous incoherent phases. The resulting atomic cluster structure can hinder grain boundary movement, achieving dispersion strengthening and grain refinement strengthening, suppressing the generation of porosity and cracks, thereby improving the strength and toughness of the aluminum-lithium alloy welding wire and weld.

[0025] The aluminum-lithium alloy welding wire provided by the present invention is prepared by the above-mentioned screening and preparation method of aluminum-lithium alloy welding wire with added high-entropy alloy powder. The aluminum-lithium alloy welding wire has stable performance, is not easy to break, and has good weld strength and toughness after welding. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder. Detailed Implementation

[0027] To demonstrate the advantages of the optimal solution for the composition of the high-entropy alloy powder selected by the method of enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder of the present invention, the following examples will be used to illustrate this.

[0028] The technical solution of the present invention will be further described and illustrated below through specific embodiments. It should be understood that the specific embodiments described herein are only for the purpose of helping to understand the present invention and are not intended to limit the present invention. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commonly used raw materials in the art, and the methods used in the embodiments are all conventional methods in the art.

[0029] Example 1:

[0030] This embodiment provides an enhanced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder. The mass percentage of each element in the welding wire is 2.1% Li, 1.4% Cu, 1.4% Mg, 0.30% TiZrHfNbTa high-entropy alloy powder, and the balance is Al and unavoidable impurity elements.

[0031] The preparation method of the reinforced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder is as follows:

[0032] (1) Melting and casting: The specified proportions of Al, Li, Mg, Cu and TiZrHfNbTa high-entropy alloy powders are placed in a vacuum induction melting furnace for melting. The melting temperature is about 800℃ and the vacuum degree is 1×10⁻⁶. -3 Pa, after melting, is cast into an ingot under the protection of argon gas, with an argon gas flow rate of about 8 ml / s.

[0033] (2) Hot extrusion: After removing impurities from the surface and both ends of the ingot, alloy wire rods are produced by continuous extrusion at 500°C.

[0034] (3) Drawing: The alloy wire rod is drawn through coarse, medium and fine drawing, and then homogenized and annealed in the middle. Finally, it is scraped and cleaned by a rotary triangular hole scraper to obtain the welding wire.

[0035] (4) Welding: The aluminum-lithium alloy reinforced welding wire with high entropy alloy powder prepared above was used to laser weld 8090 aluminum alloy. The performance of the weld sample was evaluated by physical testing, mechanical testing and microstructure characterization, and the toughness improvement effect of the selected welding wire composition in practical application was verified.

[0036] Example 2:

[0037] This embodiment provides an enhanced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder. The mass percentage of each element in the welding wire is 2.1% Li, 1.4% Cu, 1.4% Mg, 0.35% AlxCoCrFeNi high-entropy alloy powder, and the balance is Al and unavoidable impurity elements.

[0038] The preparation method of the reinforced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder is as follows:

[0039] (1) Melting and casting: The specified proportions of Al, Li, Mg, Cu and AlxCoCrFeNi high-entropy alloy powders are placed in a vacuum induction melting furnace for melting. The melting temperature is approximately 830℃ and the vacuum degree is 1×10⁻⁶. -3 Pa, after melting, is cast into an ingot under the protection of argon gas, with an argon gas flow rate of about 10 ml / s.

[0040] (2) Hot extrusion: After removing impurities from the surface and both ends of the ingot, the alloy wire rod is continuously extruded at 525°C.

[0041] (3) Drawing: The alloy wire rod is drawn through coarse, medium and fine drawing, and then homogenized and annealed in the middle. Finally, it is scraped and cleaned by a rotary triangular hole scraper to obtain the welding wire.

[0042] (4) Welding: The aluminum-lithium alloy reinforced welding wire with high entropy alloy powder prepared above was used to laser weld 2195 aluminum alloy. The performance of the weld sample was evaluated by physical testing, mechanical testing and microstructure characterization, and the strength and toughness improvement effect of the selected welding wire composition in practical application was verified.

[0043] Example 3:

[0044] This embodiment provides an enhanced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder. The mass percentage of each element in the welding wire is 2.5% Li, 1.4% Cu, 1.6% Mg, 0.30% FeNiCoCrMn high-entropy alloy powder, and the balance is Al and unavoidable impurity elements.

[0045] The preparation method of the reinforced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder is as follows:

[0046] (1) Melting and casting: The specified proportions of Al, Li, Mg, Cu, and FeNiCoCrMn high-entropy alloy powders are placed in a vacuum induction melting furnace for melting. The melting temperature is approximately 800℃, and the vacuum degree is 2×10⁻⁶. -3 Pa, after melting, is cast into an ingot under the protection of argon gas, with an argon gas flow rate of about 9 ml / s.

[0047] (2) Hot extrusion: After removing impurities from the surface and both ends of the ingot, the alloy wire rod is continuously extruded at 550°C.

[0048] (3) Drawing: The alloy wire rod is drawn through coarse, medium and fine drawing, and then homogenized and annealed in the middle. Finally, it is scraped and cleaned by a rotary triangular hole scraper to obtain the welding wire.

[0049] (4) Welding: The aluminum-lithium alloy reinforced welding wire with high entropy alloy powder prepared above was used to laser weld 2160 aluminum alloy. The performance of the weld sample was evaluated by physical testing, mechanical testing and microstructure characterization, and the strength and toughness improvement effect of the selected welding wire composition in practical application was verified.

[0050] Example 4:

[0051] This embodiment provides an enhanced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder. The mass percentage of each element in the welding wire is 2.7% Li, 1.6% Cu, 1.4% Mg, 0.35% TiZrHfNbTa high-entropy alloy powder, and the balance is Al and unavoidable impurity elements.

[0052] The preparation method of the reinforced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder is as follows:

[0053] (1) Melting and casting: The specified proportions of Al, Li, Mg, Cu and TiZrHfNbTa high-entropy alloy powders are placed in a vacuum induction melting furnace for melting. The melting temperature is about 830℃ and the vacuum degree is 1×10⁻⁶. -3 Pa, after melting, is cast into an ingot under the protection of argon gas, with an argon gas flow rate of about 10 ml / s.

[0054] (2) Hot extrusion: After removing impurities from the surface and both ends of the ingot, the alloy wire rod is continuously extruded at 525°C.

[0055] (3) Drawing: The alloy wire rod is drawn through coarse, medium and fine drawing, and then homogenized and annealed in the middle. Finally, it is scraped and cleaned by a rotary triangular hole scraper to obtain the welding wire.

[0056] (4) Welding: The aluminum-lithium alloy reinforced welding wire with high entropy alloy powder prepared above was used to laser weld 8090 aluminum alloy. The performance of the weld sample was evaluated by physical testing, mechanical testing and microstructure characterization, and the toughness improvement effect of the selected welding wire composition in practical application was verified.

[0057] High-entropy alloy powder is added during the vacuum melting process, so that the aluminum-lithium alloy welding wire contains a trace amount of high-entropy alloy powder. After welding, the purpose of dispersion strengthening of the crystal lattice structure and improvement of the eutectic distribution morphology is achieved, and an aluminum-lithium alloy welding wire with good strength and toughness is obtained.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder, characterized in that... The process of screening the optimal composition of reinforced aluminum-lithium alloy welding wire doped with high-entropy alloy powder includes the following steps: (1) Welding wire composition design: Based on performance requirements and first principles, the type and content of high-entropy alloy powder that helps improve the strength and toughness of aluminum-lithium alloy are set. The weight percentage of each component of aluminum-lithium alloy welding wire is: Li 2.1~2.7%, Cu 1.4~1.6%, Mg 1.4~1.6%, high-entropy alloy powder 0.3~0.4%, and the remainder is Al; (2) Establishment of composition design space: Based on machine learning, a correlation model and prediction model of "welding wire composition-process parameters-strength and toughness" are generated, a welding wire composition design space database is established, and a composition design space suitable for improving the strength and toughness of aluminum-lithium alloy is generated. (3) Prediction of welding wire performance: Based on the database, the type and grain size of precipitated phases are calculated according to the type and composition of the high-entropy alloy powder, and the strength and toughness of welding wire and weld are predicted to achieve synergistic improvement of the strength and toughness of aluminum-lithium alloy welding wire. (4) Optimal solution for welding wire screening and preparation: Based on the service requirements, multiple iterations of screening were carried out to complete the optimal solution screening of the composition of the reinforced aluminum-lithium alloy welding wire doped with high-entropy alloy powder, and a high-strength and high-toughness aluminum-lithium alloy welding wire doped with high-entropy alloy powder was prepared.

2. The method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder according to claim 1, characterized in that... The high-entropy alloy powders are of the following types: AlxCoCrFeNi, FeNiCoCrMn, and TiZrHfNbTa.

3. The method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder according to claim 1, characterized in that... The aforementioned "welding wire composition-process parameters-strength and toughness" correlation model and prediction model utilize resolution to solve for the correlation between welding wire composition, process parameters, and strength and toughness, and establish a mathematical model. Finally, the changes in the strength and toughness of aluminum-lithium alloy are predicted based on the residual test method.

4. The method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder according to claim 1, characterized in that... The screening method is based on service requirements, screening the interaction mechanism, precipitated phase volume, and mechanical properties of high-entropy alloy powder and aluminum-lithium alloy to obtain the optimal type and ratio of high-entropy alloy powder suitable for improving the strength and toughness of aluminum-lithium alloy welding wire.

5. The method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder according to claim 1, characterized in that... The method for preparing the aluminum-lithium alloy welding wire is to use a powder mixer to quickly and uniformly mix high-entropy alloy powder and aluminum-lithium alloy powder. The high-entropy alloy powder forms uniform reinforcing phase particles in the aluminum-lithium alloy matrix and exists as a reinforcing phase in the weld along with the aluminum-lithium alloy welding wire.

6. The method for enhancing the strength and toughness of aluminum-lithium alloy welding wire based on doped high-entropy alloy powder according to claim 1, characterized in that, The method for preparing the welding wire includes the following steps: (1) The high-entropy alloy powder and aluminum-lithium alloy raw materials in the specified proportions are smelted in a vacuum induction furnace at a smelting temperature of 800-830℃. (2) After removing impurities from the surface and both ends of the ingot, it is continuously extruded at 500-550℃ to obtain alloy wire rod. (3) After the alloy wire rod is coarsely, medium and finely drawn, it undergoes homogenization annealing in the middle and then scraping and cleaning to obtain the welding wire.

7. The method for preparing a reinforced aluminum-lithium alloy welding wire based on doped high-entropy alloy powder as described in claim 6, characterized in that: During vacuum melting, the argon flow rate is 8–10 ml / s, and the purification vacuum degree is 1 × 10⁻⁶. -3 ~2×10 -3 Pa; after fine drawing, it is made into a reinforced aluminum-lithium alloy welding wire with a diameter of 1.2mm.

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