High-strength light-weight aluminum alloy for robot and preparation method of high-strength light-weight aluminum alloy

Abstract

The invention relates to the technical field of aluminum alloy processing, in particular to a high-strength light-weight aluminum alloy for a robot and a preparation method of the high-strength light-weight aluminum alloy, and the high-strength light-weight aluminum alloy comprises the following components in percentage by mass: 0.7 to 1 percent of Zn, 2.1 to 2.8 percent of Mg, 1.2 to 2.2 percent of Cu, 0.06 to 0.12 percent of Si, 0.1 to 0.25 percent of Mn, 0.1 to 0.2 percent of Ti, 0.03 to 0.05 percent of Fe, 0.04 to 0.1 percent of Zr, 0.1 to 0.15 percent of Ni, 0.03 to 0.05 percent of Y, 0.06 to 0.09 percent of Er, 0.08 to 0.13 percent of Sc, 0.07 to 0.1 percent of Ce, 0.03 to 0.08 percent of Lu and the balance of Al and inevitable impurity elements. The total content of the non-removable impurities is not greater than 0.3%. The prepared aluminum alloy has high strength and toughness.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy processing technology, specifically to a high-strength lightweight aluminum alloy for robots and its preparation method. Background Technology

[0002] The humanoid robot industry is poised for mass production in 2025. With the continuous iteration of representative products such as Tesla's Optimus and Boston Dynamics' Atlas, lightweighting has become a core direction for industry development. For example, Tesla's Optimus second-generation product successfully reduced its weight by 10 kg compared to the first generation, bringing the overall weight down to 63 kg. Boston Dynamics' Atlas, through technologies such as topology optimization, integrated design, and 3D printing, achieved a significant weight reduction of 60% compared to its predecessor. Lightweighting offers multiple benefits for improving the performance of humanoid robots: it not only enhances the robot's endurance, alleviating energy anxiety in the context of slow progress in battery technology; it also reduces motion inertia, improving the accuracy and flexibility of movements; it allows for more design space for key components such as sensors and actuators; and it enhances safety in the event of a collision.

[0003] Among the three main paths to achieving lightweighting—material optimization, structural optimization, and process optimization—material optimization plays a fundamental role. Currently, the main metallic materials used in humanoid robot manufacturing include aluminum alloys, magnesium alloys, and titanium alloys. Compared to alternative materials such as magnesium and titanium alloys, wrought aluminum alloys have the greatest advantage in their mature industrial chain and large-scale supply capabilities. Although magnesium alloys have a lower density (1.74 g / cm³), their chemical reactivity makes them prone to oxidation, flammability, and explosion during processing, requiring extremely high production processes and resulting in significant price fluctuations. Titanium alloys have high strength and good corrosion resistance, but their density (4.5 g / cm³) is higher than aluminum, and their cost is about eight times that of aluminum alloys, making them difficult to process. Therefore, in the current process of humanoid robots moving from the laboratory to mass production, wrought aluminum alloys demonstrate significant advantages in terms of cost-effectiveness, processing maturity, and supply chain stability.

[0004] While wrought aluminum alloys play a crucial role in the lightweighting of humanoid robots, existing technologies still face numerous bottlenecks and shortcomings, hindering further performance improvements. In pursuing lightweighting, wrought aluminum alloys often fail to meet the strength requirements of load-bearing structures. The joints, bearings, and transmission components of humanoid robots need to withstand repeated load impacts, placing extremely high demands on the tensile strength, yield strength, and fatigue limit of the materials. However, existing patents such as CN110218916B (a high tensile strength aluminum alloy ingot for tire bells and its manufacturing process) and CN110218916B (a high-performance aluminum alloy material, its preparation process, and its application in the production of thermostat seats) have not achieved a balance between strength and toughness.

[0005] Therefore, there is an urgent need in the market to develop a high-strength aluminum alloy that is also tough. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention aims to provide an aluminum alloy and its preparation method. The aluminum alloy prepared by the present invention has high strength and impact resistance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a high-strength, lightweight aluminum alloy for robots, comprising, by weight percentage (100%), the following components: Zn 0.7-1%, Mg 2.1-2.8%, Cu 1.2-2.2%, Si 0.06-0.12%, Mn 0.1-0.25%, Ti 0.1-0.2%, Fe 0.03-0.05%, Zr 0.04-0.1%, Ni 0.1-0.15%, Y 0.03-0.05%, Er 0.06-0.09%, Sc 0.08-0.13%, Ce 0.07-0.1%, Lu 0.03-0.08%, with the remainder being Al and non-removable impurity elements. The total content of the non-removable impurities is not greater than 0.3%.

[0008] In some embodiments, the robot is made of a high-strength, lightweight aluminum alloy, comprising, by weight percentage (100%), the following components: Zn 0.9%, Mg 2.5%, Cu 1.7%, Si 0.1%, Mn 0.18%, Ti 0.15%, Fe 0.04%, Zr 0.07%, Ni 0.13%, Y 0.04%, Er 0.08%, Sc 0.1%, Ce 0.09%, Lu 0.05%, with the remainder being Al and non-removable impurity elements. The total content of the non-removable impurities is no more than 0.3%.

[0009] The system of this invention can simultaneously promote the composite precipitation of MgZn2 phase and Al2CuMg phase, forming a two-phase or multi-phase synergistic strengthening network, resulting in aluminum alloys with high strength and ductility. The addition of high contents of Sc, Er, and Zr, during homogenization and subsequent heat treatment, will work together to precipitate thermodynamically extremely stable Al3(Sc,Zr,Er) composite nanoparticles (L12 structure) that are completely coherent with the aluminum matrix. Compared to single Al3Zr or Al3Sc, these composite particles have a higher dissolution temperature and a slower coarsening rate, and can strongly pin dislocations and subgrain boundaries even at high temperatures up to 400°C, effectively suppressing recrystallization and obtaining an ultrafine subgrain / unrecrystallized microstructure, achieving high strength, toughness, and high thermal stability.

[0010] Furthermore, the addition of three rare earth elements—Y, Ce, and Lu—exhibits a strong affinity for impurities such as oxygen, hydrogen, and sulfur, preferentially forming fine, high-melting-point rare earth oxides or sulfides. This deeply purifies the melt, significantly improving the alloy's purity and fatigue performance. Simultaneously, trace amounts of Lu can segregate at grain boundaries, optimizing the grain boundary structure, reducing interfacial energy, and forming a synergistic "intra-grain boundary" effect with the intragranular strengthening of Sc / Er / Zr, further enhancing the alloy's toughness and creep resistance.

[0011] In addition, strictly controlling the ultra-low Fe and Si content eliminates the formation of coarse and brittle impurity phases, while Mn can form a dispersed Mn-containing phase, increasing the recrystallization temperature and improving toughness; Ni can form a heat-resistant Al-Cu-Ni phase with Cu, improving the alloy's performance retention rate at higher temperatures; Ti acts as an auxiliary grain refiner, working together with Al3(Sc,Zr,Er) to ensure a fine-grained structure during casting and welding. Through synergistic design, the strength of the aluminum alloy is improved.

[0012] A second aspect of this invention provides a method for preparing a high-strength, lightweight aluminum alloy for robots, comprising the following steps: S1: Melting: First, add pure aluminum, pure magnesium, and aluminum-silicon alloy into the melting furnace, heat to 660-700℃ and stir to completely melt the alloy. Then add pure copper, aluminum-zinc alloy, iron-aluminum alloy, aluminum-manganese alloy, aluminum-nickel alloy, aluminum-titanium alloy, and aluminum-zirconium alloy, and continue to heat to 740-760℃. After all the alloy elements have melted, aluminum alloy melt is obtained. S2: Refining: Adjust the temperature of the aluminum alloy melt obtained in step S1 to 770-780℃, add refining agent for refining treatment, let it stand after refining, remove the slag from the surface of the aluminum alloy melt, then raise the temperature to 790-810℃, add refining agent, aluminum-cerium alloy, aluminum-erbium alloy, yttrium-magnesium alloy, scandium, and lutetium, and purify with argon gas for refining. The gas pressure is controlled at 0.42-0.46MPa, and the degassing time is 7-10min. After degassing, test the composition of the aluminum alloy melt. After the test is qualified, perform the second slag removal to complete the refining process. S3: Settling: Cool the refined aluminum alloy melt from step S2 to 683-690℃; S4: Die casting: Preheat the mold cavity to 220-230℃, and then inject the molten aluminum alloy treated in step S3 into the mold cavity. The molten flow rate at the beginning of filling is 0.26-0.30m / s and the casting pressure is 30-35MPa. After the filling rate exceeds 60%, increase the molten flow rate to 1.7-1.9m / s and the casting pressure to 55-60MPa until the filling and die casting are completed, and a preliminary die casting is obtained. S5: Solution quenching treatment: The preliminary die casting obtained in step S4 is quenched and heated at a temperature of 555-560℃, the quenching holding time is 42-45min, and the resting time after quenching is 2.5-3.5h to obtain the quenched die casting. S6: Aging treatment: The quenched die casting obtained in step S5 is placed in an aging furnace and subjected to three-stage treatment to obtain a high-strength lightweight aluminum alloy for robots.

[0013] In some embodiments, the refining agent comprises, by weight, the following raw materials: 35-50 parts KCl, 15-25 parts MgCl2, 10-20 parts Na3AlF6, 5-10 parts activated calcium carbonate, 0.1-0.3 parts carbon nanotubes, 8-15 parts talc, 1-1.5 parts NdF, 1-2 parts YF, and 3-4 parts ScF.

[0014] In some embodiments, the method for preparing the refining agent includes the following steps: (1) Soak carbon nanotubes in mixed acid for 3-5 hours, wash and dry to obtain pretreated carbon nanotubes; (2) The pretreated carbon nanotubes, KCl, MgCl2, Na3AlF6, active calcium carbonate, carbon nanotubes, talc, NdF3, YF3 and ScF3 obtained in step (1) are ball-milled and then added to a mixer and stirred for 30-50 minutes. After that, they are dried at 100-120℃ and sieved to obtain the refining agent.

[0015] This invention utilizes KCl, MgCl2, Na3AlF6, and activated calcium carbonate to provide liquid coverage and dissolve the Al2O3 film, creating a clean melt environment for subsequent refining. Furthermore, three complementary rare-earth fluorides are introduced into the refining agent in a specific ratio. This combination of three components achieves microalloying modification of the alloy in a single step during refining, endowing the alloy billet with potential high strength, high toughness, high thermal stability, and biocompatibility. Additionally, carbon nanotubes undergo mixed acid pretreatment, introducing carboxyl and hydroxyl functional groups onto their surface, significantly improving their dispersibility and binding ability with the flux during subsequent ball milling. During refining, carbon nanotubes can act as adsorption carriers for ultrafine inclusions, potential heterogeneous nucleation sites during solidification, and may remain in the solid state as in-situ nano-reinforcements. Therefore, the refining agent not only has a purifying function but also enhances and toughens the aluminum alloy.

[0016] In some embodiments, the mixed acid is concentrated sulfuric acid and concentrated nitric acid.

[0017] In some embodiments, the amount of the refining agent added is 0.25-0.3% of the mass of the molten aluminum alloy.

[0018] In some embodiments, the refining agent, by weight, comprises the following raw materials: 90-100 parts aluminum, 4-5 parts chromium, 5-6 parts manganese, 2-3 parts copper, 0.3-0.4 parts lanthanum, 1-2 parts vanadium, 0.5-1 parts niobium, and 0.01-0.02 parts thulium.

[0019] Preferably, the refining agent comprises, by weight, the following raw materials: 95 parts aluminum, 4.5 parts chromium, 5.5 parts manganese, 2.5 parts copper, 0.35 parts lanthanum, 1.5 parts vanadium, 0.7 parts niobium, and 0.015 parts thulium.

[0020] In some embodiments, the amount of the refining agent added is 0.3-0.5% of the mass of the molten aluminum alloy.

[0021] In some implementations, the specific conditions for the three-stage aging process are as follows: Stage 1 aging: aging temperature of 128-136℃, aging time of 1-1.5h; Stage 2 aging: aging temperature of 167-185℃, aging time of 1-2h; Stage 3 aging: aging temperature of 223-238℃, aging time of 2-3h.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention constructs an ultra-strong nanocomposite inhibition phase through the synergistic design of each component, introduces multifunctional synergistic purification and strengthening of rare earth elements, and utilizes the precise coordination of functional transition elements to prepare an aluminum alloy with high strength and impact resistance.

[0023] (2) The present invention constructs a refining system with four functions of "physical purification - chemical refining - tissue regulation - in-situ enhancement" by using chloride salts, fluoride salts, rare earth elements, etc. Through the combination of specific functional components and key preparation processes, the effects of ultra-high purity, tissue refinement and matrix enhancement can be achieved simultaneously in a single refining operation. Detailed Implementation

[0024] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0025] In the following examples and comparative examples, the compounds and related reagents used were all commercially available. The average particle size of the activated calcium carbonate was 2-4 μm; the carbon nanotubes were multi-walled carbon nanotubes with a diameter of 8-20 nm and a length of ≤50 μm; and the average particle size of the talc was 8 ± 1.6 μm.

[0026] Unless otherwise specified, the post-processing steps such as "washing" and "drying" used below are routine operations for those skilled in the art, and can be selected according to actual operations.

[0027] Preparation Example 1 Refining Agent-1, by weight, contains the following raw materials: 40 parts KCl, 20 parts MgCl2, 15 parts Na3AlF6, 8 parts activated calcium carbonate, 0.2 parts carbon nanotubes, 10 parts talc, 1.2 parts NdF3, 1.5 parts YF3, and 3.5 parts ScF3.

[0028] The preparation method of refining agent-1 in this preparation example includes the following steps: (1) Carbon nanotubes were soaked in 85wt% concentrated sulfuric acid and 75wt% concentrated nitric acid for 4 hours, washed with deionized water and dried to obtain pretreated carbon nanotubes. (2) The pretreated carbon nanotubes, KCl, MgCl2, Na3AlF6, active calcium carbonate, carbon nanotubes, talc, NdF3, YF3 and ScF3 obtained in step (1) were ball-milled for 2 hours with a ball-to-material ratio of 5:1. Nitrogen gas was used to maintain the pressure at 0.15 MPa. Then the mixture was added to a mixer and stirred for 40 minutes. After that, it was dried at 110℃ and passed through an 80-mesh sieve to obtain refining agent-1.

[0029] Preparation Example 2 The refining agent-2 and its preparation method are the same as those in preparation example 1, except that it does not contain carbon nanotubes.

[0030] Preparation Example 3 The refining agent, by weight, comprises the following raw materials: 95 parts aluminum, 4.5 parts chromium, 5.5 parts manganese, 2.5 parts copper, 0.35 parts lanthanum, 1.5 parts vanadium, 0.7 parts niobium, and 0.015 parts thulium.

[0031] Example 1 A high-strength, lightweight aluminum alloy for robots, comprising, by weight percentage (100%), the following components: Zn 0.9%, Mg 2.5%, Cu 1.7%, Si 0.1%, Mn 0.18%, Ti 0.15%, Fe 0.04%, Zr 0.07%, Ni 0.13%, Y 0.04%, Er 0.08%, Sc 0.1%, Ce 0.09%, Lu 0.05%, with the remainder being Al and non-removable impurity elements. The total content of the non-removable impurities is no more than 0.3%.

[0032] The method for preparing high-strength, lightweight aluminum alloy for robots in this embodiment includes the following steps: S1: Melting: First, add pure aluminum, pure magnesium, and aluminum-silicon alloy into the melting furnace, heat to 680℃ and stir to completely melt the alloy. Then add pure copper, aluminum-zinc alloy, iron-aluminum alloy, aluminum-manganese alloy, aluminum-nickel alloy, aluminum-titanium alloy, and aluminum-zirconium alloy, and continue to heat to 750℃. After all the alloy elements have melted, aluminum alloy melt is obtained. S2: Refining: Adjust the temperature of the aluminum alloy melt obtained in step S1 to 775℃, add 0.28% of refining agent-1 by mass of the aluminum alloy melt for refining treatment, let it stand after refining, remove the slag from the surface of the aluminum alloy melt, then raise the temperature to 800℃, add 0.4% of refining agent, aluminum-cerium alloy, aluminum-erbium alloy, yttrium-magnesium alloy, scandium, and lutetium by mass of the aluminum alloy melt, and purify with argon gas, control the gas pressure at 0.45MPa, and degas for 9 minutes. After degassing, test the composition of the aluminum alloy melt. After the test is qualified, perform a second slag removal to complete the refining process. S3: Settling: Cool the refined aluminum alloy melt from step S2 to 687℃; S4: Die casting: Preheat the mold cavity to 225℃, and then inject the molten aluminum alloy treated in step S3 into the mold cavity. The molten flow rate at the beginning of filling is 0.28m / s and the casting pressure is 33MPa. After the filling rate exceeds 60%, increase the molten flow rate to 1.8m / s and the casting pressure to 58MPa until the filling and die casting are completed, and obtain the preliminary die casting. S5: Solution quenching treatment: The preliminary die casting obtained in step S4 is quenched and heated to a temperature of 558℃, the quenching holding time is 43min, and the resting time after quenching is 3h to obtain the quenched die casting. S6: Aging treatment: The quenched die casting obtained in step S5 is placed in an aging furnace and subjected to three stages of treatment. The first stage of aging is at an aging temperature of 132℃ and an aging time of 1.2h. The second stage of aging is at an aging temperature of 175℃ and an aging time of 1.5h. The third stage of aging is at an aging temperature of 230℃ and an aging time of 2.5h, resulting in a high-strength lightweight aluminum alloy for robots.

[0033] Example 2 A high-strength, lightweight aluminum alloy for robots, comprising, by weight percentage (100%), the following components: Zn 0.7%, Mg 2.1%, Cu 1.2%, Si 0.06%, Mn 0.1%, Ti 0.1%, Fe 0.03%, Zr 0.04%, Ni 0.1%, Y 0.03%, Er 0.06%, Sc 0.08%, Ce 0.07%, Lu 0.038%, with the remainder being Al and non-removable impurity elements. The total content of the non-removable impurities is no more than 0.3%.

[0034] The method for preparing high-strength, lightweight aluminum alloy for robots in this embodiment includes the following steps: S1: Melting: First, add pure aluminum, pure magnesium, and aluminum-silicon alloy into the melting furnace, heat to 660℃ and stir to completely melt the alloy. Then add pure copper, aluminum-zinc alloy, iron-aluminum alloy, aluminum-manganese alloy, aluminum-nickel alloy, aluminum-titanium alloy, and aluminum-zirconium alloy, and continue to heat to 740℃. After all the alloy elements have melted, aluminum alloy melt is obtained. S2: Refining: Adjust the temperature of the aluminum alloy melt obtained in step S1 to 770℃, add 0.25% of refining agent-1 by mass of the aluminum alloy melt for refining treatment, let it stand after refining, remove the slag from the surface of the aluminum alloy melt, then raise the temperature to 790℃, add 0.3% of refining agent, aluminum-cerium alloy, aluminum-erbium alloy, yttrium-magnesium alloy, scandium, and lutetium by mass of the aluminum alloy melt, and purify with argon gas, control the gas pressure at 0.42MPa, and degas for 10 minutes. After degassing, test the composition of the aluminum alloy melt. After the test is qualified, perform a second slag removal to complete the refining process. S3: Settling: Cool the refined aluminum alloy melt from step S2 to 683℃; S4: Die casting: Preheat the mold cavity to 220℃, and then inject the molten aluminum alloy treated in step S3 into the mold cavity. The molten flow rate at the beginning of filling is 0.26m / s and the casting pressure is 30MPa. After the filling rate exceeds 60%, increase the molten flow rate to 1.7m / s and the casting pressure to 55MPa until the filling and die casting are completed, and obtain the preliminary die casting. S5: Solution quenching treatment: The preliminary die casting obtained in step S4 is quenched and heated to a temperature of 555℃, the quenching holding time is 42min, and the resting time after quenching is 2.5h to obtain the quenched die casting. S6: Aging treatment: The quenched die casting obtained in step S5 is placed in an aging furnace and subjected to three stages of treatment. The first stage of aging is at an aging temperature of 128℃ and an aging time of 1.5h. The second stage of aging is at an aging temperature of 167℃ and an aging time of 2h. The third stage of aging is at an aging temperature of 223℃ and an aging time of 3h, resulting in a high-strength lightweight aluminum alloy for robots.

[0035] Example 3 A high-strength, lightweight aluminum alloy for robots, comprising, by weight percentage (100%), the following components: Zn 0.1%, Mg 2.8%, Cu 2.2%, Si 0.12%, Mn 0.25%, Ti 0.2%, Fe 0.05%, Zr 0.1%, Ni 0.15%, Y 0.05%, Er 0.09%, Sc 0.13%, Ce 0.1%, Lu 0.08%, with the remainder being Al and non-removable impurity elements. The total content of the non-removable impurities is no more than 0.3%.

[0036] The method for preparing high-strength, lightweight aluminum alloy for robots in this embodiment includes the following steps: S1: Melting: First, add pure aluminum, pure magnesium, and aluminum-silicon alloy into the melting furnace, heat to 700℃ and stir to completely melt the alloy. Then add pure copper, aluminum-zinc alloy, iron-aluminum alloy, aluminum-manganese alloy, aluminum-nickel alloy, aluminum-titanium alloy, and aluminum-zirconium alloy, and continue to heat to 760℃. After all the alloy elements have melted, aluminum alloy melt is obtained. S2: Refining: Adjust the temperature of the aluminum alloy melt obtained in step S1 to 780℃, add 0.3% of refining agent-1 by mass of the aluminum alloy melt for refining treatment, let it stand after refining, remove the slag from the surface of the aluminum alloy melt, then raise the temperature to 810℃, add 0.5% of refining agent, aluminum-cerium alloy, aluminum-erbium alloy, yttrium-magnesium alloy, scandium, and lutetium by mass of the aluminum alloy melt, and purify with argon gas, control the gas pressure at 0.46MPa, and degas for 7 minutes. After degassing, test the composition of the aluminum alloy melt. After the test is qualified, perform a second slag removal to complete the refining process. S3: Settling: Cool the refined aluminum alloy melt from step S2 to 690℃; S4: Die casting: Preheat the mold cavity to 230℃, and then inject the molten aluminum alloy treated in step S3 into the mold cavity. The molten flow rate at the beginning of filling is 0.30m / s and the casting pressure is 35MPa. After the filling rate exceeds 60%, increase the molten flow rate to 1.9m / s and the casting pressure to 60MPa until the filling and die casting are completed, and obtain the preliminary die casting. S5: Solution quenching treatment: The preliminary die casting obtained in step S4 is quenched and heated to a temperature of 560℃, the quenching holding time is 45min, and the resting time after quenching is 3.5h to obtain the quenched die casting. S6: Aging treatment: The quenched die casting obtained in step S5 is placed in an aging furnace and subjected to three stages of treatment. The first stage of aging is at an aging temperature of 136℃ and an aging time of 1 hour. The second stage of aging is at an aging temperature of 185℃ and an aging time of 1 hour. The third stage of aging is at an aging temperature of 238℃ and an aging time of 2 hours, resulting in a high-strength lightweight aluminum alloy for robots.

[0037] Example 4 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that refining agent-1 is replaced with refining agent-2 in equal amounts.

[0038] Comparative Example 1 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Y, Ce and Lu are not added.

[0039] Comparative Example 2 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Y is not added.

[0040] Comparative Example 3 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Ce is not added.

[0041] Comparative Example 4 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Lu is not added.

[0042] Comparative Example 5 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Sc, Er, and Zr are not added.

[0043] Comparative Example 6 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Sc is not added.

[0044] Comparative Example 7 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Er is not added.

[0045] Comparative Example 8 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Zr is not added.

[0046] Comparative Example 9 A high-strength lightweight aluminum alloy for robots and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that Ti is not added.

[0047] Performance testing The aluminum alloys obtained in each embodiment and comparative example were subjected to the following tests: Tensile strength: Refer to GB / T 228.1-2021 Metallic materials, tensile testing; Charpy impact performance, see GB / T 229-2020 Metallic Materials Charpy Pendulum Impact Test Method.

[0048] The test results are shown in Table 1: Table 1 As shown in Table 1, the aluminum alloys prepared in Examples 1-3 exhibit high strength and impact resistance. A comparison of the data from Example 4 and Example 1 shows that without the addition of carbon nanotubes to the refining agent, both the strength and impact resistance of the aluminum alloys decrease. A comparison of the data from Comparative Examples 1-9 and Example 1 indicates that the strength and impact resistance of the aluminum alloys prepared in this application are affected by the raw material ratio. Selecting a raw material ratio within the specified range results in aluminum alloys with high strength and good impact resistance. If the content of each element is outside the scope of protection of this application, or if certain components deviate from the formula, the strength and good impact resistance of the aluminum alloy will not achieve the expected results.

[0049] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-strength lightweight aluminum alloy for robots, characterized by comprising, in mass %, In terms of 100% by mass, the following components are included: Zn 0.7-1%, Mg 2.1-2.8%, Cu 1.2-2.2%, Si 0.06-0.12%, Mn 0.1-0.25%, Ti 0.1-0.2%, Fe 0.03-0.05%, Zr 0.04-0.1%, Ni 0.1-0.15%, Y 0.03-0.05%, Er 0.06-0.09%, Sc 0.08-0.13%, Ce 0.07-0.1%, Lu 0.03-0.08%, and the remainder is Al and non-removable impurity elements. The total content of the non-removable impurities is not more than 0.3%.

2. The high-strength light-weight aluminum alloy for robots according to claim 1, characterized by, In terms of 100% by mass, the following components are included: Zn 0.9%, Mg 2.5%, Cu 1.7%, Si 0.1%, Mn 0.18%, Ti 0.15%, Fe 0.04%, Zr 0.07%, Ni 0.13%, Y 0.04%, Er 0.08%, Sc 0.1%, Ce 0.09%, Lu 0.05%, and the remainder is Al and non-removable impurity elements. The total content of the non-removable impurities is not more than 0.3%.

3. A method of producing the high-strength light-weight aluminum alloy for robots according to claim 1 or 2, characterized by, The following steps are included: S1: Melting: first, pure aluminum, pure magnesium, and aluminum-silicon alloy are added to a smelting furnace, heated to 660-700°C, and stirred to completely melt the alloy, then pure copper, aluminum-zinc alloy, iron-aluminum alloy, aluminum-manganese alloy, aluminum-nickel alloy, aluminum-titanium alloy, and aluminum-zirconium alloy are added, and the temperature is continuously raised to 740-760°C, and after the alloy elements are completely melted, an aluminum alloy melt is obtained; S2: Refining: the temperature of the aluminum alloy melt obtained in step S1 is adjusted to 770-780°C, a refining agent is added for refining treatment, after refining is completed, the aluminum alloy melt is allowed to stand, the surface slag of the aluminum alloy melt is removed, then the temperature is raised to 790-810°C, a refiner, aluminum-cerium alloy, aluminum-erbium alloy, yttrium-magnesium alloy, scandium, and lutetium are added, argon gas is introduced for refining, the gas pressure is controlled at 0.42-0.46 MPa, the degassing time is 7-10 min, after degassing is completed, the composition of the aluminum alloy melt is inspected, after the inspection is passed, the second slag removal is performed, and the refining process is completed; S3: Standing: the aluminum alloy melt after refining in step S2 is cooled to 683-690°C; S4: Die casting: the cavity of the mold is preheated to 220-230°C, then the aluminum alloy melt after step S3 is treated is injected into the cavity of the mold, wherein the melt flow rate at the beginning of filling is 0.26-0.30 m / s, the casting pressure is 30-35 MPa, after the filling rate exceeds 60%, the melt flow rate is increased to 1.7-1.9 m / s, the casting pressure is 55-60 MPa, until the filling pressure casting is completed, and a preliminary pressure casting is obtained; S5: Solution quenching treatment: the preliminary pressure casting obtained in step S4 is subjected to quenching heating, the temperature is 555-560°C, the quenching holding time is 42-45 min, and after quenching, the standing time is 2.5-3.5 h, and a quenched pressure casting is obtained. S6: aging treatment: the quenched die casting prepared in step S5 is placed in an aging furnace, and three-stage treatment is performed to obtain a high-strength lightweight aluminum alloy for robots.

4. The method of producing a high-strength light-weight aluminum alloy for robots according to claim 3, characterized by, The refining agent comprises the following raw materials in parts by weight: KCl 35-50 parts, MgCl2 15-25 parts, Na3AlF6 10-20 parts, active calcium carbonate 5-10 parts, carbon nanotubes 0.1-0.5, talc powder 8-15 parts, NdF3 1-1.5 parts, YF3 1-2 parts, and ScF3 3-4 parts.

5. The method of producing a high-strength light-weight aluminum alloy for robots according to claim 4, characterized by, The preparation method of the refining agent comprises the following steps: (1) carbon nanotubes are soaked in mixed acid for 3-5 hours, washed and dried to obtain pretreated carbon nanotubes; (2) KCl, MgCl2, Na3AlF6, active calcium carbonate, carbon nanotubes, talc powder, NdF3, YF3 and ScF3 are ball milled and then stirred in a stirrer for 30-50 minutes, and then dried at 100-120℃, sieved to obtain the refining agent.

6. The method of producing a high-strength light-weight aluminum alloy for robots according to claim 4, characterized by, The mixed acid is concentrated sulfuric acid and concentrated nitric acid.

7. The method of producing a high-strength light-weight aluminum alloy for robots according to claim 5, characterized by, The addition amount of the refining agent is 0.25-0.3% of the mass of the aluminum alloy melt.

8. The method of producing a high-strength light-weight aluminum alloy for robots according to claim 3, characterized by, The refiner comprises the following raw materials in parts by weight: aluminum 90-100 parts, chromium 4-5 parts, manganese 5-6 parts, copper 2-3 parts, lanthanum 0.3-0.4 parts, vanadium 1-2 parts, niobium 0.5-1 parts, and thulium 0.01-0.02 parts.

9. The method of producing a high-strength light-weight aluminum alloy for robots according to claim 3, characterized by, The addition amount of the refiner is 0.3-0.5% of the mass of the aluminum alloy melt.

10. The method of producing a high-strength light-weight aluminum alloy for robots according to claim 3, characterized by, The specific conditions of the three-stage treatment are as follows: the first aging stage is at an aging temperature of 128-136℃ for 1-1.5 hours; the second aging stage is at an aging temperature of 167-185℃ for 1-2 hours; and the third aging stage is at an aging temperature of 223-238℃ for 2-3 hours.

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