A high-strength aluminum-based alloy material and its production process

Abstract

The present invention belongs to the technical field of aluminum alloy materials, and in particular relates to a high-strength aluminum-based alloy material and a production process thereof. The high-strength aluminum-based alloy material provided by the present invention comprises 1.0%-3.2% magnesium, 1.0%-2.7% zirconium, 1.25%-1.53% manganese, 0.8%-1.4% copper, 0.2%-0.5% vanadium, 0.7%-1.0% nano-strengthener and the remainder aluminum. The present invention optimizes the formula of the aluminum-based alloy material, adopts a ZrOCl2·8H2O aqueous solution and a precipitant to prepare the nano-strengthener by a sol-gel method, forms a dispersion strengthener in the aluminum-based alloy material and plays a pinning role, effectively hinders the development of microcracks and promotes grain refinement, thereby enhancing the mechanical properties of the alloy. The high-strength aluminum-based alloy material provided by the present invention has a tensile strength greater than 625MPa, a yield strength greater than 597MPa, an elongation greater than 20%, and excellent comprehensive performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum alloy materials, and in particular relates to a high-strength aluminum-based alloy material and a production process thereof. Background Art

[0002] Aluminum alloy is an alloy with aluminum as the matrix and a certain amount of other alloying elements added. It is one of the light metal materials with high strength, good casting properties and plastic processing properties, good electrical and thermal conductivity, good corrosion resistance and weldability. It can be used as a structural material and is used in aerospace, aviation, transportation, construction, electromechanical, light chemical industry and daily necessities.

[0003] Among the aluminum alloy materials currently available for additive manufacturing, only some Al-Si alloys and a very small number of Al-Mg alloys are capable of laser additive forming. However, Al-Si alloys are affected by the material system and the inherent solid solubility of elements in aluminum alloys, resulting in insufficient material performance. While Al-Mg alloys have good strength, the high Mg content added during the forming process in pursuit of high strength results in the formation of large amounts of volatile smoke and dust under laser bombardment. The high porosity of the material affects the density of the material. Although the formed material has high strength, it is prone to fatigue instability, which seriously affects its practical application and promotion. Furthermore, the Al-Mg alloys currently used are all strengthened with Sc, i.e., the Al-Mg-Sc system. The high price of raw materials also limits the application and promotion of the material.

[0004] The effectiveness of developing new aluminum alloys using traditional preparation methods, such as increasing alloy purity, adjusting composition, and changing heat treatment specifications, has become increasingly limited. To significantly improve material properties such as strength, corrosion resistance, heat resistance, and fracture toughness, aluminum alloy materials are produced by atomizing the aluminum alloy melt, rapidly solidifying it into a powder, and then pressing, sintering, and pressure-processing the powder. The resulting materials have fine grains, refined intermetallic compound particles, uniform chemical composition, increased supersaturated solid solubility of alloying elements, and the combined effects of dispersion strengthening, solid solution strengthening, and aging strengthening, resulting in high strength and excellent stress corrosion resistance. However, currently produced aluminum alloy powders are primarily produced using inert gas atomization or centrifugal atomization, resulting in low particle dispersion and prone to sticking. Lubricating binders such as paraffin wax and zinc stearate are often added to facilitate powder forming, but this process introduces impurities into the aluminum alloy powder, affecting the material's strength.

[0005] Chinese patent application publication number CN109954884A discloses a method for charging and molding high-strength, hard-to-deform aluminum alloy powder using powder metallurgy. Specifically, the aluminum alloy powder undergoes mechanical ball milling pretreatment and then is soaked in anhydrous ethanol. The powder is then loaded into a powder loading device, hydraulically pressed, and then encased in a welded cover and degassing aluminum tube. Finally, the powder is heated to remove any residual ethanol in the encasing tube. This method omits the cold isostatic pressing step, shortening the production cycle. However, the aluminum alloy powder used is gas-atomized powder, which has low dispersion and is prone to sticking. Summary of the Invention

[0006] In order to solve the technical problem of poor mechanical properties existing in the related art, the purpose of the present invention is to provide a high-strength aluminum-based alloy material and a production process thereof.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows:

[0008] A high-strength aluminum-based alloy material, comprising the following components by mass percentage:

[0009] The invention comprises 1.0%-3.2% of magnesium, 1.0%-2.7% of zirconium, 1.25%-1.53% of manganese, 0.8%-1.4% of copper, 0.2%-0.5% of vanadium, 0.7%-1.0% of nano-strengthener and the balance of aluminum; the nano-strengthener is prepared from ZrOCl2·8H2O and a precipitant by a sol-gel method.

[0010] Traditional additively manufactured aluminum alloys have a high content of alloying elements. During the laser additive manufacturing process, the internal stress of the molded parts is large due to the high temperature gradient inside the molten pool and the fast solidification rate, which easily produces thermal crack defects and reduces the mechanical properties. The nano-strengthening agent with nano effect used in the present invention is easier to disperse evenly in the aluminum alloy matrix, forming a dispersion strengthener and playing a pinning role, effectively hindering the development of microcracks and promoting grain refinement, further enhancing the mechanical properties of the alloy.

[0011] Aluminum-magnesium alloys suitable for additive manufacturing contain a high magnesium content, but magnesium volatilizes during the 3D printing process, generating large amounts of black smoke and forming holes on the aluminum alloy surface, which reduces the yield strength of the aluminum alloy. In the present invention, zirconium is used to replace part of the magnesium. The addition of zirconium promotes the formation of Al3Zr precipitation phases, resulting in grain boundary pinning. It also acts as a non-uniform nucleation point in the aluminum alloy, effectively reducing the grain size of the aluminum alloy, thereby reducing the aluminum alloy's sensitivity to cracks and improving its mechanical strength. Vanadium has a low diffusivity in aluminum alloys and can enhance the high-temperature strength of aluminum alloys. Furthermore, vanadium can react with aluminum in the aluminum alloy through a eutectic reaction to form intermetallic compounds, which refines the grains, increases the recrystallization temperature, and improves mechanical properties.

[0012] Furthermore, the preparation method of the nano-strengthener is specifically as follows: (1) adding a ZrOCl2·8H2O aqueous solution and ammonia water to a precipitant solution at the same time, stirring the reaction, and standing for aging to obtain a Zr(OH)4 gel; (2) filtering and washing the Zr(OH)4 gel obtained in step (1) to obtain a Zr(OH)4 hydrogel; (3) adding anhydrous ethanol to the Zr(OH)4 hydrogel obtained in step (2), stirring, filtering, drying, grinding, and then heating under the condition of introducing nitrogen for heat treatment, cooling, and grinding to obtain a nano-strengthener.

[0013] The present invention uses a ZrOCl2·8H2O aqueous solution and a precipitant to prepare zirconium oxide nanopowder via a sol-gel method. The particle size and specific surface area of the zirconium oxide nanopowder are further controlled by controlling the temperature and time of the heat treatment. Studies have shown that when the heat treatment temperature is too high or the time is too long, the particle size of the resulting zirconium oxide nanopowder increases and the specific surface area decreases. Furthermore, the addition of anhydrous ethanol to the hydrogel displaces water in the hydrogel, forming an alcohol gel. Heat treatment under flowing nitrogen effectively removes moisture from the gel, preventing hard agglomeration of the zirconium oxide nanopowder and facilitating the production of nanometer-sized zirconium oxide nanoparticles.

[0014] Furthermore, in the preparation method of the nano-strengthener, the concentration of the ZrOCl2·8H2O aqueous solution in step (1) is 0.1-0.2 mol / L, the pH value of the ammonia water is 9-10, the dropping speed of the ZrOCl2·8H2O aqueous solution and the ammonia water is 2.8-3.2 mL / min, the precipitant is an ammonia aqueous solution with a mass percentage of 2.5%-3.0%, the stirring reaction time is 2-2.5 h, and the static aging time is 8-10 h.

[0015] Furthermore, in the step (3) of the preparation method of the nano-strengthener, the heat treatment temperature is 400-450° C., and the heat treatment time is 3.8-4.3 h.

[0016] Furthermore, the mass fractions of the components in the preparation method of the nano-strengthener are: 20-30 parts of ZrOCl2·8H2O aqueous solution, 10-16 parts of ammonia water, 10-15 parts of precipitant solution, and 8-12 parts of anhydrous ethanol.

[0017] Furthermore, the high-strength aluminum-based alloy material includes the following components, calculated by mass percentage: 2.4% magnesium, 1.9% zirconium, 1.35% manganese, 1.1% copper, 0.4% vanadium, 0.9% nano-strengthener and the balance aluminum.

[0018] The present invention also provides a production process of the high-strength aluminum-based alloy material, comprising the following steps:

[0019] S1: Add the various components of the high-strength aluminum-based alloy material formula into a melting furnace, heat and melt them under the protection of inert gas to obtain a metal solution;

[0020] S2: The metal solution obtained in step S1 is vacuum atomized by an inert gas to obtain a high-strength aluminum-based alloy material.

[0021] Furthermore, the inert gas in step S1 and step S2 of the production process of the high-strength aluminum-based alloy material is helium or argon, and the pressure of the inert gas added to the melting furnace in step S1 is 2.4-3.0 MPa.

[0022] In the present invention, the volatilization of elements in the aluminum-based alloy material is reduced by controlling the pressure in the melting furnace.

[0023] Furthermore, the heating and melting temperature in step S1 of the production process of the high-strength aluminum-based alloy material is 1250-1400°C.

[0024] Furthermore, the flow rate of the metal solution in step S2 of the production process of the high-strength aluminum-based alloy material is 10-15 g / s.

[0025] Compared with the existing technology, the high-strength aluminum-based alloy material and its production process provided by the present invention have the following technical advantages:

[0026] (1) The present invention optimizes the formula of aluminum-based alloy materials, effectively reducing the grain size of aluminum alloys and improving mechanical strength;

[0027] (2) In the present invention, a nano-strengthening agent is prepared by a sol-gel method using a ZrOCl2·8H2O aqueous solution and a precipitant, which forms a dispersion strengthening agent in the aluminum-based alloy material and plays a pinning role, effectively hindering the development of microcracks and promoting grain refinement, further enhancing the mechanical properties of the alloy;

[0028] (3) The high-strength aluminum-based alloy material provided by the present invention has a tensile strength greater than 625 MPa, a yield strength greater than 597 MPa, an elongation greater than 20%, and excellent comprehensive performance. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments. Those skilled in the art can make various modifications based on the basic idea of the present invention, but as long as they do not depart from the basic idea of the present invention, they are all within the scope of the present invention.

[0030] Example 1

[0031] A high-strength aluminum-based alloy material, comprising the following components by mass percentage:

[0032] Magnesium 1.0%, zirconium 2.7%, manganese 1.25%, copper 0.8%, vanadium 0.2%, nano-strengthener 0.7% and the balance aluminum.

[0033] The preparation method of the nano-strengthener is specifically as follows: (1) 20 g of a 0.1 mol / L ZrOCl2·8H2O aqueous solution and 10 g of ammonia water with a pH value of 9 are simultaneously added dropwise to 10 g of a 2.5% ammonia aqueous solution at a rate of 2.8 mL / min, stirred for reaction for 2 h, and allowed to stand for aging for 8 h to obtain Zr(OH)4 gel; (2) the Zr(OH)4 gel obtained in step (1) is filtered and washed until no chloride ions are left in the washing liquid to obtain Zr(OH)4 hydrogel; (3) 8 g of anhydrous ethanol is added to the Zr(OH)4 hydrogel obtained in step (2), stirred for 2 h, filtered, and the filter cake obtained is placed in a vacuum drying oven and dried at 100°C for 24 h, taken out and ground into powder, heated to 400°C under nitrogen flow for heat treatment for 3.8 h, cooled, and ground to obtain the nano-strengthener.

[0034] The production process of high-strength aluminum-based alloy materials includes the following steps:

[0035] S1: Add the various components of the high-strength aluminum-based alloy material formula into a melting furnace, evacuate the furnace, introduce helium or argon, maintain the pressure in the melting furnace at 2.4 MPa, heat to 1250°C to melt, and obtain a metal solution;

[0036] S2: The metal solution obtained in step S1 is vacuum atomized by an inert gas at a flow rate of 10 g / s to obtain a high-strength aluminum-based alloy material.

[0037] Example 2

[0038] A high-strength aluminum-based alloy material, comprising the following components by mass percentage:

[0039] Magnesium 3.2%, zirconium 1.0%, manganese 1.53%, copper 1.4%, vanadium 0.5%, nano-strengthener 1.0% and the balance aluminum.

[0040] The preparation method of the nano-strengthener is as follows: (1) 30 g of a 0.2 mol / L ZrOCl2·8H2O aqueous solution and 16 g of ammonia water with a pH value of 10 are simultaneously added dropwise to 15 g of a 3.0% ammonia aqueous solution at a rate of 3.2 mL / min, stirred for reaction for 2.5 h, and allowed to stand for aging for 10 h to obtain Zr(OH)4 gel; (2) the Zr(OH)4 gel obtained in step (1) is filtered and washed until no chloride ions are left in the washing liquid to obtain Zr(OH)4 hydrogel; (3) 12 g of anhydrous ethanol is added to the Zr(OH)4 hydrogel obtained in step (2), stirred for 2 h, filtered, and the filter cake obtained is placed in a vacuum drying oven and dried at 100°C for 24 h, taken out and ground into powder, heated to 450°C under nitrogen flow for heat treatment for 4.3 h, cooled, and ground to obtain the nano-strengthener.

[0041] The production process of high-strength aluminum-based alloy materials includes the following steps:

[0042] S1: Add the components of the high-strength aluminum-based alloy material formula into a melting furnace, evacuate the furnace, introduce helium or argon, maintain the pressure in the melting furnace at 3.0 MPa, heat to 1400°C to melt, and obtain a metal solution;

[0043] S2: The metal solution obtained in step S1 is vacuum atomized by an inert gas at a flow rate of 15 g / s to obtain a high-strength aluminum-based alloy material.

[0044] Example 3

[0045] A high-strength aluminum-based alloy material, comprising the following components by mass percentage:

[0046] Magnesium 2.4%, zirconium 1.9%, manganese 1.35%, copper 1.1%, vanadium 0.4%, nano-strengthener 0.9% and the balance aluminum.

[0047] The preparation method of the nano-strengthener is as follows: (1) 26 g of a 0.15 mol / L ZrOCl2·8H2O aqueous solution and 13 g of ammonia water with a pH value of 9.5 are simultaneously added dropwise at a rate of 3.0 mL / min to 12 g of a 2.8% ammonia aqueous solution, stirred for reaction for 2.2 h, and allowed to stand for aging for 9.2 h to obtain Zr(OH)4 gel; (2) the Zr(OH)4 gel obtained in step (1) is filtered and washed until no chloride ions are left in the washing liquid to obtain Zr(OH)4 hydrogel; (3) 10 g of anhydrous ethanol is added to the Zr(OH)4 hydrogel obtained in step (2), stirred for 2 h, filtered, and the filter cake obtained is placed in a vacuum drying oven and dried at 100°C for 24 h, taken out and ground into powder, heated to 430°C under nitrogen flow for heat treatment for 4.0 h, cooled, and ground to obtain the nano-strengthener.

[0048] The production process of high-strength aluminum-based alloy materials includes the following steps:

[0049] S1: Add the components of the high-strength aluminum-based alloy material formula into a melting furnace, evacuate the furnace and introduce helium or argon gas, maintain the pressure in the melting furnace at 2.8 MPa, heat to 1310°C to melt, and obtain a metal solution;

[0050] S2: The metal solution obtained in step S1 is vacuum atomized by an inert gas at a flow rate of 13 g / s to obtain a high-strength aluminum-based alloy material.

[0051] Comparative Example 1

[0052] The formula and preparation method of the aluminum-based alloy material in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that an equal amount of magnesium is used instead of zirconium in this comparative example.

[0053] Comparative Example 2

[0054] The formula and preparation method of the aluminum-based alloy material in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that an equal amount of aluminum is used instead of vanadium in this comparative example.

[0055] Comparative Example 3

[0056] The formula and preparation method of the aluminum-based alloy material in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that an equal amount of aluminum is used instead of manganese in this comparative example.

[0057] Comparative Example 4

[0058] The formula and preparation method of the aluminum-based alloy material in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that an equal amount of aluminum is used to replace the nano-strengthener in this comparative example.

[0059] Comparative Example 5

[0060] The formula and preparation method of the aluminum-based alloy material in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that the heat treatment temperature in the preparation method of the nano-strengthener in this comparative example is 600° C. and the heat treatment time is 4.5 h.

[0061] Comparative Example 6

[0062] The formula and preparation method of the aluminum-based alloy material in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that an equal amount of deionized water is used instead of anhydrous ethanol in the preparation method of the nano-strengthening agent in this comparative example.

[0063] Comparative Example 7

[0064] The formula and preparation method of the aluminum-based alloy material described in this comparative example are similar to those of Example 3. The difference between this comparative example and Example 3 is that in step S1 of the production process of the aluminum-based material in this comparative example, the pressure in the melting furnace is controlled to be 1.0 MPa.

[0065] Test example

[0066] In this test example, aluminum alloy materials prepared in Examples 1-3 and Comparative Examples 1-7 were used to produce 10×10 cm aluminum alloy molded parts using 3D printing technology. Yield strength, tensile strength, and elongation were tested in accordance with GB / T 222-2002, Metallic Materials, Room Temperature Tensile Test Methods. The test results are shown in Table 1.

[0067] Table 1 Mechanical properties test results

[0068]

[0069] As shown in Table 1, the molded parts made using the high-strength aluminum-based alloy material provided by the present invention have a tensile strength greater than 625 MPa, a yield strength greater than 597 MPa, and an elongation greater than 20%. This demonstrates that the high-strength aluminum-based alloy material provided by the present invention has excellent mechanical properties. The aluminum-based alloy material produced in Example 3 exhibits the best performance in all aspects and is the most preferred embodiment of the present invention.

[0070] Compared with Example 3, in Comparative Example 1, an equal amount of magnesium was used instead of zirconium, but the yield strength of the alloy material obtained was significantly reduced. This is because the magnesium content was too high, which volatilized during the 3D printing process and formed holes on the surface of the aluminum-based alloy material, resulting in a decrease in yield strength; in Comparative Example 2, an equal amount of aluminum was used instead of vanadium, but the mechanical properties of the alloy material obtained were reduced to varying degrees, which shows that the addition of vanadium can improve the mechanical properties of the aluminum-based alloy material; in Comparative Example 3, an equal amount of aluminum was used instead of manganese, but the mechanical properties of the alloy material obtained were reduced to varying degrees, which shows that the formula of the present invention has been optimized; in Comparative Example 4, an equal amount of aluminum was used instead of the nano-strengthener, but the mechanical properties of the alloy material obtained were significantly worsened, which shows that the nano-strengthener is uniformly dispersed in the aluminum alloy matrix, which can play a role of dispersion strengthening and pinning, effectively hinder the development of microcracks, and improve the mechanical properties of the alloy; in the preparation method of the nano-strengthener in Comparative Example 5, the heat treatment temperature and time were changed, but the The mechanical properties of the obtained alloy materials are reduced to varying degrees, which shows that in the preparation process of the nano-strengthener, the temperature and time of the heat treatment are the key to controlling the particle size of the nano-strengthener. If the temperature is too high or the time is too long, the larger the particle size of the obtained nano-strengthener will be, and the uneven dispersion in the alloy material will affect the mechanical properties of the alloy material; in the preparation method of the nano-strengthener in Comparative Example 6, an equal amount of deionized water is used instead of anhydrous ethanol, but the mechanical properties of the obtained alloy materials are reduced to varying degrees. This is because in the preparation process of the nano-strengthener, the water in the hydrogel evaporates unevenly or incompletely, resulting in uneven particle size of the nano-strengthener, and the dispersion effect of the nano-strengthener added to the alloy material is weak, resulting in reduced mechanical properties; Comparative Example 7 changes the pressure in the melting furnace in step S1 of the aluminum-based material production process, but the yield strength of the obtained alloy material is reduced, which shows that after changing the pressure in the melting furnace, the magnesium element in the raw material will volatilize, forming holes on the surface of the alloy material, resulting in a decrease in yield strength.

[0071] The above examples are merely illustrative of the preparation methods of the present invention and are not intended to limit the present invention. Any person skilled in the art is prohibited from modifying the above examples without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or variations made by one of ordinary skill in the art without departing from the technical principles of the present invention are encompassed by the claims of the present invention.

Claims

1. A high-strength aluminum-based alloy material, characterized in that: Calculated by mass percentage, it includes the following components: 1.0%-3.2% of magnesium, 1.0%-2.7% of zirconium, 1.25%-1.53% of manganese, 0.8%-1.4% of copper, 0.2%-0.5% of vanadium, 0.7%-1.0% of nano-strengthening agent and the balance of aluminum; the nano-strengthening agent is prepared by ZrOCl2·8H2O and a precipitant using a sol-gel method, and the preparation method is as follows: (1) adding ZrOCl2·8H2O aqueous solution and ammonia water to the precipitant solution at the same time, stirring the reaction mixture, and stirring the mixture to obtain a nano-strengthening agent; , standing and aging to obtain Zr(OH)4 gel; (2) filtering and washing the Zr(OH)4 gel obtained in step (1) to obtain Zr(OH)4 hydrogel; (3) adding anhydrous ethanol to the Zr(OH)4 hydrogel obtained in step (2), stirring, filtering, drying, grinding, heating to 400-450°C under the condition of passing nitrogen, and heat treatment for 3.8-4.3h, cooling, grinding, and obtaining a nano-strengthening agent.

2. The high-strength aluminum-based alloy material according to claim 1, characterized in that: The concentration of the ZrOCl2·8H2O aqueous solution in step (1) is 0.1-0.2 mol / L, the pH value of the ammonia water is 9-10, the dropwise addition rate of the ZrOCl2·8H2O aqueous solution and the ammonia water is 2.8-3.2 mL / min, the precipitant is an ammonia water solution with a mass percentage of 2.5%-3.0%, the stirring reaction time is 2-2.5 h, and the static aging time is 8-10 h.

3. The high-strength aluminum-based alloy material according to claim 1, characterized in that: The mass fractions of the components in the preparation method of the nano-strengthener are: 20-30 parts of ZrOCl2·8H2O aqueous solution, 10-16 parts of ammonia water, 10-15 parts of precipitant solution, and 8-12 parts of anhydrous ethanol.

4. The high-strength aluminum-based alloy material according to claim 1, characterized in that: Calculated by mass percentage, the material includes the following components: 2.4% magnesium, 1.9% zirconium, 1.35% manganese, 1.1% copper, 0.4% vanadium, 0.9% nano-strengthener and the balance aluminum.

5. The production process of the high-strength aluminum-based alloy material according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Add the various components of the high-strength aluminum-based alloy material formula into a melting furnace, heat and melt them under the protection of inert gas to obtain a metal solution; S2: The metal solution obtained in step S1 is vacuum atomized by an inert gas to obtain a high-strength aluminum-based alloy material.

6. The production process of the high-strength aluminum-based alloy material according to claim 5, characterized in that: The inert gas in step S1 and step S2 is helium or argon. The pressure of the inert gas added into the melting furnace in step S1 is 2.4-3.0 MPa.

7. The production process of the high-strength aluminum-based alloy material according to claim 5, characterized in that: The heating and melting temperature in step S1 is 1250-1400°C.

8. The production process of high-strength aluminum-based alloy material according to claim 5, characterized in that: The flow rate of the metal solution in step S2 is 10-15 g / s.

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