Aluminum alloy composition, aluminum alloy part and preparation method of aluminum alloy part

Abstract

The invention relates to an aluminum alloy composition, an aluminum alloy part and a preparation method of the aluminum alloy part. The aluminum alloy composition comprises, by weight, 3.5%-11.5% of Zn, 1.8%-2.6% of Mg, 0.3%-1.6% of Cu, 0.25% or less of Fe, 0.6%-1.8% of Co, 0.5%-1.5% of Ni, 0.4%-0.68% of Ti, 0.1%-0.15% of Sc, 0%-0.15% of Zr, 0.08%-0.3% of SiC, 2.2%-3.6% of Al92Ti2Fe2Co2Ni2 and the balance Al. According to the aluminum alloy composition, the strength of an aluminum alloy workpiece is effectively improved, and the plasticity and the welding manufacturability of the aluminum alloy workpiece are improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of aluminum alloy materials, and in particular, to an aluminum alloy composition, an aluminum alloy product and a preparation method thereof. Background Art

[0002] As people pay more and more attention to environmental protection and low carbon, the pace of development of new energy vehicles has also accelerated significantly. The integration of automobiles with related technologies in the fields of energy, transportation, information and communication has accelerated, and electrification, networking and intelligence have become the development trend and trend of the automobile industry. New technologies for new energy vehicles have sprung up like mushrooms after a rain, for example: the application number is CN202410658157.7, the publication number is CN118238797A, and the invention name is new energy vehicle energy intelligent management system, control method and related equipment; the application number is CN202410672579.X, the publication number is CN118597091A, and the invention name is new energy vehicle energy intelligent management method, system and related equipment; the application number is CN202010470247.5, the publication number is CN113734146B, and the invention name is vehicle driving mode selection method, device, equipment and medium; the above existing technologies all describe hybrid technology based on electricity, which has multiple advantages such as fast, economical, quiet, smooth and green. The application number is CN202211678720.4, the publication number is CN117382629A, and the invention name is vehicle power control method, device, medium, vehicle controller and vehicle; the application number is CN202311164098.X, the publication number is CN116890770A, and the invention name is vehicle control system, method and vehicle; the application number is CN202311170393.6, the publication number is CN117533292A, and the invention name is vehicle control system, control method, controller and vehicle; the above prior arts all describe a new energy power system with four wheel-side motors independently driven as the core, which greatly improves the safety and power of new energy vehicles. In addition, the longitudinal beams of the drone hangar can also be made of extruded aluminum alloy profiles. The commonly used extruded aluminum alloys are mainly 6 series and 7 series aluminum alloys.

[0003] The aluminum alloys commonly used in the prior art are mainly 6-series and 7-series aluminum alloys, whose strengthening principle is to utilize solid solution strengthening and precipitation phase strengthening. Since the solid solution strengthening solute elements are limitedly dissolved in the aluminum alloy matrix, the space for further improving the strength of the aluminum alloy is relatively limited. This type of product has the following major disadvantages: 1. Low strength, 2. Low plasticity, 3. Welding is prone to cracking, and the welding processability is poor. The existing aluminum alloy materials have limited effect in improving the above problems. Summary of the invention

[0004] The purpose of the present disclosure is to provide an aluminum alloy composition, an aluminum alloy product and a preparation method thereof, which can effectively improve the strength of the aluminum alloy product and improve the plasticity and welding processability of the aluminum alloy product.

[0005] In order to achieve the above-mentioned object, the first aspect of the present disclosure provides an aluminum alloy composition, based on the total weight of the aluminum alloy composition, the aluminum alloy composition comprises: 3.5-11.5 wt % of Zn, 1.8-2.6 wt % of Mg, 0.3-1.6 wt % of Cu, 0.25 wt % or less of Fe, 0.6-1.8 wt % of Co, 0.5-1.5 wt % of Ni, 0.4-0.68 wt % of Ti, 0.1-0.15 wt % of Sc, 0-0.15 wt % of Zr, 0.08-0.3 wt % of SiC, 2.2-3.6 wt % of Al; 92 Ti2Fe2Co2Ni2 and the balance Al.

[0006] Optionally, based on the total weight of the aluminum alloy composition, the aluminum alloy composition includes: 5.5-7.8 wt % Zn, 2.2-2.6 wt % Mg, 0.6-1.2 wt % Cu, less than 0.2 wt % Fe, 0.8-1.2 wt % Co, 0.8-1.2 wt % Ni, 0.4-0.6 wt % Ti, 0.12-0.15 wt % Sc, 0.1-0.12 wt % Zr, 0.12-0.15 wt % SiC, 2.8-3.2 wt % Al 92 Ti2Fe2Co2Ni2 and the balance Al.

[0007] Optionally, in the aluminum alloy composition, the weight ratio of Mg:SiC is 9-22; the weight ratio of Zn to Mg is 1.8-5.6.

[0008] Optionally, the Al 92 Ti2Fe2Co2Ni2 is prepared by a method comprising the following steps: Ti-24Al-15Nb, Fe, Co, Ni and the balance of AlSi10Mg are mixed to obtain a raw material mixture; preferably, based on the total weight of the raw material mixture, the content of Ti-24Al-15Nb is 2.6-3.8 wt %, the content of Fe is 1.2-2.0 wt %, the content of Co is 1.8-2.5 wt %, and the content of Ni is 1.8-2.6 wt %; performing selective laser melting treatment on the raw material mixture; Preferably, the Ti-24Al-15Nb, Fe, Co, Ni and AlSi10Mg are powders, and the particle size is independently 15-80 μm; Preferably, the conditions of the selective laser melting treatment include: under protective gas, temperature of 120-180°C, power of 260-350W, scanning speed of 800-1200mm / s, layer thickness of 20-50μm; the protective gas includes argon.

[0009] A second aspect of the present disclosure provides a method for preparing an aluminum alloy part, comprising the following steps: S1. subjecting the aluminum alloy composition, the refining agent and the grain refiner according to the first aspect of the present disclosure to smelting treatment and melt-casting treatment to obtain a first product; S2, subjecting the first product to plastic extrusion treatment to obtain a second product; S3, subjecting the second product to a heating solution treatment and an aging treatment.

[0010] Optionally, in step S1, the grain refiner includes Al-5Ti-B; based on the total weight of the Al-5Ti-B, the Al content is 92.2~96.8% by weight, the Ti content is 4.1~6.8% by weight, and the B content is 0.4~1.4% by weight; based on the total weight of the melt of the aluminum alloy composition, the grain refiner is added in an amount of 0.05~0.30% by weight.

[0011] Optionally, step S1 includes: (1-1) heating a smelting furnace to a first temperature, adding other components of the aluminum alloy composition except magnesium into the smelting furnace, and adding the refining agent and the grain refiner into the lower part of the smelting furnace; heating the smelting furnace to a second temperature, performing a first smelting process, and obtaining a first melt; (1-2) Cooling the first melt to a third temperature, adding magnesium in the aluminum alloy composition to the first melt, and stopping adding the grain refiner; continuing to introduce the refining agent into the upper, middle and lower parts of the smelting furnace to perform a second smelting treatment; stopping adding the refining agent and performing a standing treatment.

[0012] Optionally, the first temperature is 360-405° C., the second temperature is 760-795° C., and the first smelting treatment time is 40-100 min; The third temperature is 660-720° C., the second smelting treatment time is 20-70 min; the standing treatment time is 10-30 min; In step (1-1), the refining agent is argon gas with a purity of 99.99% or more; the flow rate of the refining agent is 500-800 L / min; the pressure of the refining agent is 1.5-2.8 MPa; In step (1-2), the refining agent is argon gas with a purity of 99.99% or more; the flow rate of the refining agent satisfies the following conditions: L 下 =L 中 +60~100L / min=L 上 +120~180L / min; L 上 L is the flow rate of the refining agent introduced into the upper part of the smelting furnace; 中 L is the flow rate of the refining agent introduced into the middle of the smelting furnace; 下 is the flow rate of the refining agent introduced into the lower part of the smelting furnace; and / or, The pressure of the refining agent satisfies the following conditions: P 下 =P 中 +0.2~0.4MPa=P 上 +0.3~0.6MPa; among which, P 上 P is the pressure of the refining agent introduced into the upper part of the smelting furnace; 中 P is the pressure of the refining agent introduced into the middle of the smelting furnace; 下 is the pressure of the refining agent introduced into the lower part of the smelting furnace; The conditions of the melt casting process include: a casting temperature of 720-760°C, a casting speed of 42-58 mm / min, a casting water flow rate of 28-42 m 3 / h, the electromagnetic stirring frequency is 8-15Hz; the first product obtained by the melt-casting process is an aluminum alloy cast rod, and the diameter of the aluminum alloy cast rod is ≥600mm.

[0013] Optionally, in step S2, the plastic extrusion process includes a first-stage extrusion process and a second-stage extrusion process performed sequentially; wherein, The conditions of the first-stage extrusion treatment include: extrusion temperature of 440-475°C, extrusion speed of 14-20 m / min, and extrusion ratio of 32-50; The conditions of the second-stage extrusion treatment include: an extrusion temperature of 425-460° C., an extrusion speed of 4-10 m / min, and an extrusion ratio of 14-28.

[0014] Optionally, in step S3, the conditions of the heating solution treatment include: a heating temperature of 430-460° C. and a heating time of 9-16 h; The cryogenic treatment conditions include: the cryogenic medium includes liquid nitrogen at a temperature of -165°C to -130°C, and the treatment time is 2 to 8 hours; The conditions of the aging treatment include: a temperature of 150-180° C. and a heat preservation time of 4-12 hours.

[0015] A third aspect of the present disclosure provides an aluminum alloy part prepared by the method described in the second aspect of the present disclosure.

[0016] Through the above technical solution, the present invention provides an aluminum alloy composition, an aluminum alloy product and a preparation method thereof. The aluminum alloy composition provided by the present invention adds nano-strengthening phase SiC, a composite component Al 92 The aluminum alloy prepared by the composition of Ti2Fe2Co2Ni2 and rare earth elements (Sc) includes nano-strengthening phase SiC, plastic strain induced strengthening phase nano-scale mesentropy alloy Al3Ti / Al9(Fe,Co,Ni)2 and rare earth element strengthening phase Al3Sc. The nano-strengthening phase SiC is dispersed in the aluminum alloy matrix under the induction of Mg element. The nano-scale complex phase mesentropy alloy Al3Ti / Al9(Fe,Co,Ni)2 presents lamellar distribution due to plastic strain induced precipitation during the plastic processing of aluminum alloy. The rare earth element strengthening phase Al3Sc precipitates in a spherical distribution during the solidification process, which can achieve a composite strengthening effect, which can not only effectively improve the strength performance of aluminum alloy parts, but also effectively improve the plasticity and welding processability of aluminum alloy parts.

[0017] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 This is a TEM photo of the aluminum alloy prepared in Example 1 of the present disclosure; Figure 2 This is a TEM photograph of the aluminum alloy prepared in Example 1 of the present disclosure. DETAILED DESCRIPTION

[0019] The specific embodiments of the present disclosure are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0020] A first aspect of the present disclosure provides an aluminum alloy composition, based on the total weight of the aluminum alloy composition, the aluminum alloy composition comprises: 3.5-11.5 wt % Zn, 1.8-2.6 wt % Mg, 0.3-1.6 wt % Cu, 0.25 wt % or less Fe, 0.6-1.8 wt % Co, 0.5-1.5 wt % Ni, 0.4-0.68 wt % Ti, 0.1-0.1 wt % Sc, 0-0.15 wt % Zr, 0.08-0.3 wt % SiC, 2.2-3.6 wt % Al. 92 Ti2Fe2Co2Ni2 and the balance Al.

[0021] The present invention discloses an aluminum alloy composition, wherein the aluminum alloy composition is added with nano-strengthening phase SiC, a composite component Al 92 The aluminum alloy prepared by the composition of Ti2Fe2Co2Ni2 and rare earth elements (Sc) includes nano-strengthening phase SiC, plastic strain induced strengthening phase nano-scale mesentropy alloy Al3Ti / Al9(Fe,Co,Ni)2 and rare earth element strengthening phase Al3Sc. The nano-strengthening phase SiC is dispersed in the aluminum alloy under the induction of Mg element. The nano-scale complex phase mesentropy alloy Al3Ti / Al9(Fe,Co,Ni)2 presents lamellar distribution due to plastic strain induced precipitation during the plastic processing of aluminum alloy. The rare earth element strengthening phase Al3Sc precipitates in a spherical distribution during the solidification process, which can achieve a composite strengthening effect, which can not only effectively improve the strength performance of aluminum alloy parts, but also effectively improve the plasticity and welding processability of aluminum alloy parts.

[0022] According to the present disclosure, Mg and SiC are added within the content range provided in the present disclosure, and the Mg element induces nano-SiC to be dispersed in the aluminum alloy matrix, which improves the mechanical properties of the material and inhibits the formation of aluminum alloy welding cracks during welding, thereby improving the welding processability of the aluminum alloy.

[0023] According to the present disclosure, Fe and Si are harmful elements in 7 series aluminum alloys. Fe and Si exist in the form of FeAl3 and free Si in 7 series aluminum alloys. Some Fe and Si will also form β-FeSiAl3 phase and α-Fe2SiAl8 phase. This state of existence significantly reduces the fracture toughness of aluminum alloys and increases the crack tendency of aluminum alloy profiles. In addition, FeAl3 is distributed in the aluminum alloy matrix. Because the corrosion potential is inconsistent with the aluminum matrix, the strength of the aluminum alloy is reduced, and the refinement of the aluminum alloy grain size is interfered with, and the effect of the grain refiner is weakened. The aluminum alloy composition provided by the present disclosure generates Al3Ti and Al9(Fe, Co, Ni)2 by strain induction. Co and Ni are excessive relative to Fe. Through chemical metallurgy and similar dissolution, Fe is segregated with Co and Ni with similar chemical properties, and the generation of FeAl3 is inhibited. The self-purification of Fe is achieved in the metallurgical process, which can well control the size of the grains in the aluminum alloy, reduce the deterioration of the performance of the aluminum alloy by the Fe and Si elements in the aluminum alloy, improve the performance of the aluminum alloy, and reduce the crack tendency of the aluminum alloy profile.

[0024] According to the present disclosure, the rare earth element Sc precipitates the precipitation strengthening phase Al3Sc in a spherical distribution during the aging strengthening heat treatment of the aluminum alloy, which can inhibit the expansion of microcracks and further improve the comprehensive mechanical properties and welding processability of the aluminum alloy.

[0025] In a preferred embodiment, based on the total weight of the aluminum alloy composition, the aluminum alloy composition includes: 5.5-7.8 wt % Zn, 2.2-2.6 wt % Mg, 0.6-1.2 wt % Cu, less than 0.2 wt % Fe, 0.8-1.2 wt % Co, 0.8-1.2 wt % Ni, 0.4-0.6 wt % Ti, 0.12-0.15 wt % Sc, 0-0.12 wt % Zr, 0.12-0.15 wt % SiC, 2.8-3.2 wt % Al 92 Ti2Fe2Co2Ni2 and the balance of Al; Preferably, based on the total weight of the aluminum alloy composition, the aluminum alloy composition comprises: 5.5-7.8 wt % Zn, 2.2-2.6 wt % Mg, 0.6-1.2 wt % Cu, less than 0.2 wt % Fe, 0.8-1.2 wt % Co, 0.8-1.2 wt % Ni, 0.4-0.6 wt % Ti, 0.12-0.15 wt % Sc, 0.1-0.12 wt % Zr, 0.12-0.15 wt % SiC, 2.8-3.2 wt % Al 92 Ti2Fe2Co2Ni2 and the balance of Al. The aluminum alloy composition having the component contents of this embodiment can be used to prepare an aluminum alloy material with higher strength and better plasticity and welding processability.

[0026] In a preferred embodiment, in the aluminum alloy composition, the weight ratio of Mg:SiC is 9 to 22, preferably 12 to 16. By controlling the weight ratio of Mg to SiC in the aluminum alloy composition within the range of this embodiment, especially within the preferred range, it can have a better effect of improving the mechanical properties of the aluminum alloy, and better inhibit the formation of aluminum alloy welding cracks during the welding process, thereby improving the welding processability of the aluminum alloy.

[0027] In a preferred embodiment, in the aluminum alloy composition, the weight ratio of Zn to Mg is 1.8 to 5.6, preferably 2.4 to 3.6. When the weight ratio of Zn to Mg in the aluminum alloy composition is within the range of this embodiment, especially within the preferred range, the aluminum alloy material prepared using the aluminum alloy composition has better properties, such as higher tensile strength and elongation.

[0028] In one embodiment, the Al 92Ti2Fe2Co2Ni2 is prepared by a method comprising the following steps: mixing Ti-24Al-15Nb, Fe, Co, Ni and the remainder of AlSi10Mg to obtain a raw material mixture; preferably, based on the total weight of the raw material mixture, the content of Ti-24Al-15Nb is 3.2% by weight, the content of Fe is 1.6% by weight, the content of Co is 2.1% by weight, and the content of Ni is 2.2% by weight; The raw material mixture is subjected to a selective laser melting process (SLM).

[0029] In a preferred embodiment, the Ti-24Al-15Nb, Fe, Co, Ni and AlSi10Mg are powders, and the particle size is independently 15 to 80 μm, preferably 20 to 60 μm. Using raw material powders with a particle size within the range of this embodiment, Al2O3 with better performance can be prepared. 92 Ti2Fe2Co2Ni2.

[0030] In a specific embodiment, the conditions of the selective laser melting treatment include: preheating to a temperature of 120~180°C under a protective gas, a power of 260~350W, a scanning speed of 800~1200mm / s, and a layer thickness of 20~50μm; the protective gas includes argon.

[0031] A second aspect of the present disclosure provides a method for preparing an aluminum alloy part, comprising the following steps: S1. Smelting and casting the aluminum alloy composition, refining agent and grain refiner according to the first aspect of the present disclosure to obtain a first product; S2, subjecting the first product to plastic extrusion treatment to obtain a second product; S3, subjecting the second product to a heating solution treatment, an optional deep freezing treatment and an aging treatment.

[0032] The present invention provides a method for preparing an aluminum alloy product, wherein the aluminum alloy composition is first subjected to a smelting process and a melt-casting process to obtain a first product, and then subjected to a plastic extrusion process to obtain an aluminum alloy product. 92Ti2Fe2Co2Ni2 induces precipitation of Al3Ti / Al9(Fe, Co, Ni)2 in a lamellar distribution through plastic strain, and the introduction of transition elements forms a thermodynamically and kinetically dual-stable complex phase structure. Compared with traditional intermetallic compounds, the introduction of more components makes it more stable. The Al3Ti in the complex phase structure remains coherent with the matrix aluminum alloy, and Al9(Fe, Co, Ni)2 can be activated to produce dislocations and stacking faults under high stress, which can greatly improve the strength of the aluminum alloy while improving the plasticity of the aluminum alloy. The method provided by the present invention can be used to prepare aluminum alloys, which can also effectively reduce the grain size of the aluminum alloy, and is more conducive to improving the hot working crack resistance of the aluminum alloy.

[0033] In a specific embodiment, in step S1, the grain refiner includes Al-5Ti-B; based on the total weight of the Al-5Ti-B, the Al content is 92.2-96.8% by weight, the Ti content is 4.1-6.8% by weight, and the B content is 0.4-1.4% by weight; preferably, based on the total weight of the Al-5Ti-B, the Al content is 93.4-94.8% by weight, the Ti content is 4.5-5.5% by weight, and the B content is 0.6-1.2% by weight. The use of the Al-5Ti-B grain refiner having the composition in this embodiment can further reduce the grain size of the aluminum alloy to improve the strength, plasticity and other properties of the aluminum alloy.

[0034] In a preferred embodiment, based on the total weight of the melt of the aluminum alloy composition, the added amount of the grain refiner is 0.05~0.30% by weight, preferably 0.12~0.20% by weight. According to the added amount in this embodiment, especially according to the preferred added amount, adding the grain refiner to the melt of the aluminum alloy composition can achieve a better grain refining effect and improve the performance of the aluminum alloy parts.

[0035] In a preferred embodiment, step S1 comprises: (1-1) heating a smelting furnace to a first temperature, adding other components of the aluminum alloy composition except magnesium into the smelting furnace, and adding the refining agent and the grain refiner into the lower part of the smelting furnace; heating the smelting furnace to a second temperature, performing a first smelting process, and obtaining a first melt; (1-2) Cooling the first melt to a third temperature, adding magnesium in the aluminum alloy composition to the first melt, and stopping adding the grain refiner; continuing to introduce the refining agent into the upper, middle and lower parts of the smelting furnace to perform a second smelting treatment; stopping adding the refining agent and performing a static treatment. In this embodiment, the timing of adding magnesium and other components to the smelting furnace is differentiated according to the temperature, which has the effect of low burnout of the magnesium alloy and easier and more uniform composition control.

[0036] In a specific embodiment, the first temperature is 360-405°C, the second temperature is 760-795°C, and the first smelting treatment time is 40-100 min; preferably, the first temperature is 375-390°C, the second temperature is 775-785°C, and the first smelting treatment time is 60-80 min; The third temperature is 660~720℃, the second smelting treatment time is 20~70min; the standing treatment time is 10~30min; preferably, the third temperature is 675~705℃, the second smelting treatment time is 35~50min; the standing treatment time is 10~20min; according to the process conditions in this embodiment, especially according to the preferred process conditions, more excellent smelting effect can be obtained to improve the strength, plasticity and other properties of aluminum alloy parts.

[0037] In a preferred embodiment, in step (1-1), the refining agent is argon gas with a purity of 99.99% or more; the flow rate of the refining agent is 500-800 L / min, preferably 580-650 L / min; the pressure of the refining agent is 1.5-2.8 MPa, preferably 2.4-2.6 MPa; In step (1-2), the refining agent is argon gas with a purity of 99.99% or more; the flow rate of the refining agent satisfies the following conditions: L 下 =L 中 +60~100L / min=L 上 +120~180L / min; preferably, L 下 =L 中 +70~100L / min=L 上 +160~180L / min; L 上 L is the flow rate of the refining agent introduced into the upper part of the smelting furnace; 中 L is the flow rate of the refining agent introduced into the middle of the smelting furnace; 下 is the flow rate of the refining agent introduced into the lower part of the smelting furnace; and / or, The pressure of the refining agent satisfies the following conditions: P 下 =P 中 +0.2~0.4MPa=P 上 +0.3~0.6MPa, preferably, P 下 =P 中 +0.25~0.35MPa=P 上 +0.4~0.5MPa; among which, P 上 P is the pressure of the refining agent introduced into the upper part of the smelting furnace; 中P is the pressure of the refining agent introduced into the middle of the smelting furnace; 下 is the pressure of the refining agent introduced into the lower part of the smelting furnace; during the smelting process, the flow rate or pressure of the refining agent at different positions in the smelting furnace is controlled to meet the relationship range provided in this embodiment, so that the metallurgical reaction environment of the alloy elements can be stable and the reaction can be sufficient and uniform.

[0038] In a specific embodiment, in step S1, the conditions of the melt casting process include: a casting temperature of 720-760°C, a casting speed of 42-58 mm / min, and a casting water flow rate of 28-42 m / min. 3 / h, the electromagnetic stirring frequency is 8~15Hz; preferably, the casting temperature is 730~740℃, the casting speed is 48~52mm / min, and the casting water flow rate is 30~35m 3 / h, the electromagnetic stirring frequency is 9~12Hz; The first product obtained by the melting and casting process is an aluminum alloy cast rod, the diameter of the aluminum alloy cast rod is ≥600mm, preferably 600-800mm. The aluminum alloy cast rod prepared by melting and casting process according to the process conditions in this embodiment has high strength and good plasticity.

[0039] In one embodiment, in step S2, the plastic extrusion process includes a first-stage extrusion process and a second-stage extrusion process performed sequentially; wherein, The conditions of the first stage extrusion treatment include: extrusion temperature of 440-475°C, extrusion speed of 14-20 m / min, and extrusion ratio of 32-50; preferably, extrusion temperature of 455-465°C, extrusion speed of 14-18 m / min, and extrusion ratio of 35-45; The conditions of the second stage extrusion treatment include: extrusion temperature of 425-460°C, extrusion speed of 4-10 m / min, and extrusion ratio of 14-28; preferably, extrusion temperature of 435-445°C, extrusion speed of 4-8 m / min, and extrusion ratio of 22-26. According to the process conditions in this embodiment, especially according to the preferred process conditions, the effect of plastic strain induced strengthening phase nanoscale mesoentropy alloy Al3Ti / Al9(Fe, Co, Ni)2 and rare earth element strengthening phase Al3Sc can be further improved to improve the performance of aluminum alloy parts.

[0040] In one embodiment, in step S3, the conditions for the heating solution treatment include: a heating temperature of 430-460° C. and a heating time of 9-16 hours; preferably, a heating temperature of 440-450° C. and a heating time of 10-12 hours; The cryogenic treatment conditions include: the cryogenic medium includes liquid nitrogen at a temperature of -165°C to -130°C, and the treatment time is 2 to 8 hours; preferably, the temperature of the liquid nitrogen is -145°C to -130°C, and the treatment time is 2 to 6 hours; The aging treatment conditions include: a temperature of 150-180°C and a holding time of 4-12 hours; preferably, a temperature of 160-170°C and a holding time of 6-8 hours. According to the process conditions in this embodiment, especially according to the preferred process conditions, heating solution treatment and aging treatment can be performed to obtain aluminum alloy parts with better performance.

[0041] A third aspect of the present disclosure provides an aluminum alloy part prepared by the method described in the second aspect of the present disclosure.

[0042] In a specific embodiment, the aluminum alloy part includes: Zn: 5.8 wt. %, Mg: 2.2 wt. %, Cu: 0.8 wt. %, Fe: 0.22 wt. %, Co: 1.4 wt. %, Ni: 1.2 wt. %, Ti: 0.45 wt. %, Sc: 0.12 wt. %, SiC: 0.082 wt. %, Al 92 Ti2Fe2Co2Ni2: 2.8 wt%, the balance is Al.

[0043] In a specific embodiment, the aluminum alloy product has a tensile strength of 702-780 MPa, an elongation of 9.4-16.1%, and a grain size of 25-55 μm; preferably, the aluminum alloy has a tensile strength of 724-756 MPa, an elongation of 10.6-14.8%, and a grain size of 32-50 μm. The aluminum alloy product provided by the present disclosure has a finer grain size, and the tensile strength and elongation are also significantly improved.

[0044] The aluminum alloy parts provided by the present disclosure can be applied to fields such as drones, vehicles, and vehicle exterior parts.

[0045] According to the present disclosure, the application of the aluminum alloy parts in UAVs includes but is not limited to longitudinal beams, hangar frames, connecting seats and other load-bearing components; the application in vehicles includes but is not limited to body side beams; the application in vehicle exterior trim includes but is not limited to roof luggage racks. The aluminum alloy parts provided by the present disclosure can have excellent application effects in multiple fields and meet performance requirements.

[0046] The present disclosure is further described in detail below through examples. The raw materials used in the examples can all be obtained through commercial channels.

[0047] In the following examples, the microstructure of the aluminum alloy samples was measured using a TEM electron microscope (JEM-2100, manufactured by JEOL Ltd.).

[0048] In the following examples and comparative examples, the Al 92 Ti2Fe2Co2Ni2 is prepared by a method comprising the following steps: Ti-24Al-15Nb, Fe, Co, Ni and the remainder of AlSi10Mg are mixed to obtain a raw material mixture; preferably, based on the total weight of the raw material mixture, the content of Ti-24Al-15Nb is 3.2% by weight, the content of Fe is 1.6% by weight, the content of Co is 2.1% by weight, and the content of Ni is 2.2% by weight; the Ti-24Al-15Nb, Fe, Co, Ni and AlSi10Mg are powders, and the particle sizes are all in the range of 15-80 μm; In the following examples and comparative examples, the grain refiner includes Al-5Ti-B; based on the total weight of the Al-5Ti-B, the content of Al is 94.2% by weight, the content of Ti is 5.1% by weight, and the content of B is 0.7% by weight; it can be purchased through common commercial channels; The raw material mixture is subjected to selective laser melting treatment; the conditions of the selective laser melting treatment include: preheating to a temperature of 150° C., a power of 300 W, a scanning speed of 1000 mm / s, a layer thickness of 35 μm, and argon protection.

[0049] Example 1 This embodiment prepares an aluminum alloy product according to the raw material ratio of the aluminum alloy components listed in Table 1A, including the following steps: (1) Heat the smelting furnace to 380°C (first temperature) and add aluminum ingots, zinc ingots, aluminum-copper master alloy, Co, Ni, Ti, Sc, SiC and Al 92 Ti2Fe2Co2Ni2, and then immediately introduce argon gas with a purity of 99.99% into the smelting furnace as a refining agent, and at the same time introduce Al-5Ti-B wire into the lower part of the smelting furnace as a grain refiner; wherein, the flow rate of the refining agent introduced into the lower part of the smelting furnace is 650L / min, and the pressure is 2.6MPa; The temperature of the smelting furnace is increased and controlled to be 780°C (second temperature), and the first smelting treatment is carried out for 60 minutes; after the alloy raw material is melted, the temperature is lowered to 680°C (third temperature), and the magnesium ingot is added and the introduction of the grain refiner Al-5Ti-B wire is stopped. At the same time, the refining agent is continued to be introduced into the upper, middle and lower parts of the smelting furnace, wherein the flow rate of the refining agent introduced into the lower part of the smelting furnace (L 下 ) is 620L / min, pressure (P 下 ) is 2.7MPa; the flow rate of the refining agent introduced into the middle of the smelting furnace (L 中 ) is 550L / min, pressure (P 中) is 2.4MPa; the flow rate of the refining agent introduced into the upper part of the smelting furnace (L 上 ) is 460L / min, pressure (P 上 ) is 2.2MPa; after continuing the heat preservation and smelting for 25min (second smelting treatment), the refining agent is stopped and the smelting is left to stand for 12min. During the whole aluminum alloy smelting process, the amount of Al-5Ti-B wire added is 0.16% by weight of the total mass of the liquid aluminum alloy melt. Among them, L 下 =L 中 +70L / min=L 上 +160L / min;P 下 =P 中 +0.3MPa=P 上 +0.4MPa; After refining and standing, the scum on the surface of the melt was scraped off and degassed; the semi-continuous casting method was used for casting and molding, and electromagnetic stirring was assisted. The casting temperature was controlled to be 738°C, the casting speed was 52mm / min, and the casting water flow was 35m 3 / h, the electromagnetic stirring frequency is 10Hz, and the aluminum alloy casting rod with the specification of Ф800mm×2200mm is obtained; (2) feeding the aluminum alloy cast rod obtained in step (1) into an extrusion barrel of an extruder for secondary extrusion treatment to obtain an aluminum alloy profile; wherein the extrusion temperature of the first stage extrusion treatment is 460±2°C, the extrusion speed is 16m / min, and the extrusion ratio is 40; the extrusion temperature of the second stage extrusion treatment is 440±2°C, the extrusion speed is 6m / min, and the extrusion ratio is 24; (3) Place the aluminum alloy profile obtained in step (2) in a heating furnace at 450±2°C for solution treatment for 12 hours. (4) The aluminum alloy profile after the solution treatment in step (3) is subjected to aging treatment at a temperature of 165° C. and a holding time of 6 hours.

[0050] The TEM microstructure of the aluminum alloy product prepared in this example is as follows: Figure 1~2 As shown by Figure 1 It can be seen that the aluminum alloy product obtained in this embodiment includes Al3Ti phase and Al9(Fe, Co, Ni)2 phase; Figure 2 As shown, the aluminum alloy product obtained in the embodiment includes Al3Sc phase, and the precipitation strengthened phase Al3Sc is distributed in a spherical shape.

[0051] Example 2 In this embodiment, aluminum alloy parts are prepared according to the raw material ratios of the aluminum alloy components listed in Table 1A; The preparation process of this embodiment is similar to that of embodiment 1, and the difference from embodiment 1 is that: After the solution treatment in step (3), cryogenic treatment is performed. The conditions of the cryogenic treatment include: the cryogenic medium is liquid nitrogen at a temperature of -140°C, and the treatment time is 4 hours; the rest of the process is the same as in Example 1.

[0052] Embodiments 3 to 8 In this embodiment, an aluminum alloy product is prepared according to the raw material ratios of the aluminum alloy components listed in Table 1A; the preparation process is the same as that of Example 1.

[0053] Example 9 This example refers to the preparation method in Example 1, and the difference from Example 1 is that: The flow rate of the refining agent introduced into the lower part of the smelting furnace (L 下 ) is 620L / min, pressure (P 下 ) is 2.0MPa; the flow rate of the refining agent introduced into the middle of the smelting furnace (L 中 ) is 560L / min, pressure (P 中 ) is 1.8MPa; the flow rate of the refining agent introduced into the upper part of the smelting furnace (L 上 ) is 500L / min, pressure (P 上 ) is 1.6MPa, where L 下 =L 中 +60L / min=L 上 +120L / min; P 下 =P 中 +0.2MPa=P 上 +0.4MPa; the rest of the process is the same as in Example 1 to prepare an aluminum alloy.

[0054] Example 10 This example refers to the preparation method in Example 1, and the difference from Example 1 is that: In the secondary extrusion treatment, the extrusion temperature of the first stage extrusion treatment is 450±2°C, the extrusion speed is 20m / min, and the extrusion ratio is 50; the extrusion temperature of the second stage extrusion treatment is 430±2°C, the extrusion speed is 10m / min, and the extrusion ratio is 28; the rest of the process is the same as in Example 1, and an aluminum alloy is prepared.

[0055] Embodiment 11 This example refers to the preparation method in Example 1, and the difference from Example 1 is that: Based on the total weight of the melt of the aluminum alloy composition, the addition amount of the grain refiner Al-5Ti-B is 0.06% by weight; the rest of the process is the same as in Example 1 to prepare an aluminum alloy.

[0056] Example 12 This example refers to the preparation method in Example 1, and the difference from Example 1 is that: Based on the total weight of the melt of the aluminum alloy composition, the addition amount of the grain refiner Al-5Ti-B is 0.04% by weight; the rest of the process is the same as in Example 1 to prepare an aluminum alloy.

[0057] Comparative Example 1 Aluminum alloy parts are prepared according to the following raw material ratios: Zn: 5.60 wt%, Mg: 2.55 wt%, Cu: 1.41 wt%, Fe: 0.20 wt%, Cr: 0.2 wt%, Mn: 0.06 wt%, Ti: 0.02 wt%, Si: 0.08 wt%, and the balance is Al. The following steps are included: (1) The raw materials are mixed according to the proportion, and after drying, they are melted and alloyed in an electromagnetic induction furnace to form a melt; wherein the melting conditions include: heating the melting furnace to 350°C, adding aluminum ingots, zinc ingots and aluminum-copper master alloy, and then immediately introducing argon gas with a purity of 99.99% as a refining agent into the lower part of the melting furnace, and simultaneously introducing Al-Ti-B wire as a grain refiner into the lower part of the melting furnace; wherein the flow rate of the refining agent introduced into the lower part of the melting furnace is 600 L / min, and the pressure is 2.5 MPa; the alloying conditions include: raising the temperature of the melting furnace and controlling the melting temperature to 770°C, cooling the temperature to 680°C after the alloy raw materials are melted, adding magnesium ingots and stopping the introduction of grain refiner Al-Ti-B wire, continuing to melt at the temperature for 20 minutes, and then standing for 10 minutes. During the entire aluminum alloy smelting process, the amount of Al-Ti-B wire added is 0.15% by weight of the total mass of the liquid aluminum alloy melt; (2) The melt is transferred to a refining furnace for standing and degassing; the refining conditions include: adjusting the alloy liquid temperature to 720°C~730°C, using aluminum alloy refining equipment for argon refining treatment; the speed is set to 400r / min, the gas flow rate is 15L / min, and the refining time is 10min; (3) The melt after standing and degassing in step (2) is transferred into a casting furnace, and a semi-continuous casting process is used to cast rods under inert gas protection and electromagnetic stirring; the semi-continuous casting process conditions include: controlling the casting temperature to 735°C, the casting speed to 50 mm / min, and the casting water flow rate to 32 m 3 / h; (4) The aluminum alloy cast rod of step (3) is extruded by an extruder, and then subjected to solution treatment and aging treatment; the extrusion molding conditions include: the extrusion temperature of the first stage extrusion treatment is 455±2°C, the extrusion speed is 16m / min, and the extrusion ratio is 35; the extrusion temperature of the second stage extrusion treatment is 435±2°C, the extrusion speed is 16m / min, and the extrusion ratio is 24; the solution treatment conditions include: solution temperature, 450±5°C, and solution time is 12h; the aging treatment conditions include: aging temperature, 165±5°C, and treatment time is 4h.

[0058] Comparative Example 2 Using conventional 6 series aluminum alloy (6061-T6 aluminum alloy).

[0059] Comparative Example 3 Using conventional 7 series aluminum alloy (7075-T6 aluminum alloy).

[0060] Comparative Examples 4 to 8 Aluminum alloy parts were prepared according to the raw material ratios of the aluminum alloy components listed in Table 1B; the preparation process was the same as that in Example 1.

[0061] Table 1A

[0062] Table 1B

[0063] Test Case The mechanical properties of the aluminum alloy parts obtained in the above embodiments and comparative examples were tested in accordance with GB / T228-2010 "Tensile Test of Metallic Materials Part 1: Room Temperature Test Methods". The grain size of the aluminum alloy parts was tested using a metallographic microscope (manufacturer and model: Zeiss / AxscopeA1). The test results are listed in Table 2 below.

[0064] Table 2

[0065] According to the data in Table 2 above, we can see that: Comparative Example 1: Aluminum alloy was prepared by conventional process, and the composite component Al was not added to the raw material of the aluminum alloy composition. 92 Ti2Fe2Co2Ni2, the grain size of the aluminum alloy obtained in Comparative Example 1 is relatively large, and the tensile strength and elongation are relatively low; conventional 6 series and 7 series aluminum alloys are used in Comparative Examples 2 and 3, respectively, and the grain size of the aluminum alloys in Comparative Examples 2 and 3 is relatively large, and the tensile strength and elongation are also relatively low; Comparing Examples 1, 3 to 8 with Comparative Examples 4 to 8, on the basis of the same preparation process, the composite component Al was not added in Comparative Example 4. 92Ti2Fe2Co2Ni2, the composite component Al in Comparative Examples 5-6 92 The addition amount of Ti2Fe2Co2Ni2 is not within the scope provided in the present disclosure; Zn in Comparative Examples 7-8 is not within the scope provided in the present disclosure, and the ratio of Zn / Mg in the raw material is not within the scope provided in the present application, and the grain size of the aluminum alloy prepared in Comparative Examples 4-8 is large, and the tensile strength and elongation are low; the aluminum alloy parts prepared in Examples 1, 3-8 according to the aluminum alloy composition of the composition provided in the present disclosure can simultaneously have a smaller grain size and higher tensile strength and elongation, and the comprehensive performance of the aluminum alloy is better; Comparing Example 3 with Examples 5-6, it can be seen that the Mg / SiC ratio of the aluminum alloy composition in Examples 5-6 is not within the optimized range provided in the present application, and the aluminum alloy obtained in Example 3 can simultaneously have a smaller grain size, as well as higher tensile strength and elongation; Comparing Example 3 with Examples 7-8, it can be seen that the Zn / Mg ratio of the aluminum alloy composition in Examples 7-8 is not within the preferred range provided in the present application, and the aluminum alloy obtained in Example 3 can simultaneously have a smaller grain size, as well as higher tensile strength and elongation; Comparing Example 1 with Example 3, it can be seen that the composition of the aluminum alloy composition used in Example 1 is within the preferred range provided in the present application, and the ratio of Mg / SiC is also within the preferred range. The grain size of the aluminum alloy obtained in Example 1 is smaller, and the tensile strength and elongation are higher; Comparing Example 1 with Example 4, it can be seen that the composition of the aluminum alloy composition in Example 4 is within the further preferred range provided by the present disclosure (Zr is added), and the grain size of the aluminum alloy obtained in Example 4 is smaller, and the tensile strength and elongation are higher; Comparing Example 1 with Example 9, it can be seen that the flow rate relationship and pressure relationship of the refining agent introduced into the upper, middle and lower parts of the smelting furnace in the process of preparing the aluminum alloy in Example 1 are within the preferred range provided in the present disclosure; comparing Example 1 with Example 10, it can be seen that in the aluminum alloy preparation process of Example 1, the conditions of the secondary extrusion treatment are within the preferred range provided in the present disclosure; compared with the aluminum alloys obtained in Examples 9 to 10, the aluminum alloy obtained in Example 1 has a smaller grain size, and has higher tensile strength and elongation; Comparing Example 11 with Example 12, it can be seen that the addition amount of grain refiner Al-5Ti-B in Example 11 is within the optimization range provided in the present disclosure, and the aluminum alloy prepared in Example 11 has a smaller grain size, and higher tensile strength and elongation; further comparing Example 11 with Example 1, the addition amount of Al-5Ti-B in Example 1 is within the further preferred range provided in the present disclosure, and the aluminum alloy obtained in Example 1 has a smaller grain size, and higher tensile strength and elongation.

[0066] The preferred embodiments of the present disclosure are described in detail above; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0067] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0068] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. An aluminum alloy composition, characterized in that Based on the total weight of the aluminum alloy composition, the aluminum alloy composition includes: 3.5-11.5 wt % Zn, 1.8-2.6 wt % Mg, 0.3-1.6 wt % Cu, 0.25 wt % or less Fe, 0.6-1.8 wt % Co, 0.5-1.5 wt % Ni, 0.4-0.68 wt % Ti, 0.1-0.15 wt % Sc, 0-0.15 wt % Zr, 0.08-0.3 wt % SiC, 2.2-3.6 wt % Al 92 Ti2Fe2Co2Ni2 and the balance Al.

2. The aluminum alloy composition according to claim 1, characterized in that Based on the total weight of the aluminum alloy composition, the aluminum alloy composition includes: 5.5-7.8 wt % Zn, 2.2-2.6 wt % Mg, 0.6-1.2 wt % Cu, less than 0.2 wt % Fe, 0.8-1.2 wt % Co, 0.8-1.2 wt % Ni, 0.4-0.6 wt % Ti, 0.12-0.15 wt % Sc, 0.1-0.12 wt % Zr, 0.12-0.15 wt % SiC, 2.8-3.2 wt % Al 92 Ti2Fe2Co2Ni2 and the balance Al.

3. The aluminum alloy composition according to claim 1, characterized in that In the aluminum alloy composition, the weight ratio of Mg:SiC is 9-22; the weight ratio of Zn to Mg is 1.8-5.

6.

4. The aluminum alloy composition according to claim 1, characterized in that The Al 92 Ti2Fe2Co2Ni2 is prepared by a method comprising the following steps: Ti-24Al-15Nb, Fe, Co, Ni and the balance of AlSi10Mg are mixed to obtain a raw material mixture; preferably, based on the total weight of the raw material mixture, the content of Ti-24Al-15Nb is 2.6-3.8 wt %, the content of Fe is 1.2-2.0 wt %, the content of Co is 1.8-2.5 wt %, and the content of Ni is 1.8-2.6 wt %; performing selective laser melting treatment on the raw material mixture; Preferably, the Ti-24Al-15Nb, Fe, Co, Ni and AlSi10Mg are powders, and the particle size is independently 15-80 μm; Preferably, the conditions of the selective laser melting treatment include: under protective gas, temperature of 120-180°C, power of 260-350W, scanning speed of 800-1200mm / s, layer thickness of 20-50μm; the protective gas includes argon.

5. A method for preparing an aluminum alloy part, characterized in that: The following steps are involved: S1. Smelting and casting the aluminum alloy composition according to any one of claims 1 to 4, a refining agent and a grain refiner to obtain a first product; S2, subjecting the first product to plastic extrusion treatment to obtain a second product; S3, subjecting the second product to a heating solution treatment, an optional deep freezing treatment and an aging treatment.

6. The method according to claim 5, characterized in that In step S1, the grain refiner includes Al-5Ti-B; based on the total weight of the Al-5Ti-B, the content of Al is 92.2-96.8% by weight, the content of Ti is 4.1-6.8% by weight, and the content of B is 0.4-1.4% by weight; based on the total weight of the melt of the aluminum alloy composition, the amount of the grain refiner added is 0.05-0.30% by weight.

7. The method according to claim 5, characterized in that Step S1 includes: (1-1) heating a smelting furnace to a first temperature, adding other components of the aluminum alloy composition except magnesium into the smelting furnace, and adding the refining agent and the grain refiner into the lower part of the smelting furnace; heating the smelting furnace to a second temperature, performing a first smelting process, and obtaining a first melt; (1-2) Cooling the first melt to a third temperature, adding magnesium in the aluminum alloy composition to the first melt, and stopping adding the grain refiner; continuing to introduce the refining agent into the upper, middle and lower parts of the smelting furnace to perform a second smelting treatment; stopping adding the refining agent and performing a standing treatment.

8. The method according to claim 7, characterized in that The first temperature is 360-405° C., the second temperature is 760-795° C., and the first smelting treatment time is 40-100 min; The third temperature is 660-720° C., the second smelting treatment time is 20-70 min; the standing treatment time is 10-30 min; In step (1-1), the refining agent is argon gas with a purity of 99.99% or more; the flow rate of the refining agent is 500-800 L / min; the pressure of the refining agent is 1.5-2.8 MPa; In step (1-2), the refining agent is argon gas with a purity of 99.99% or more; the flow rate of the refining agent satisfies the following conditions: L 下 =L 中 +60~100L / min=L 上 +120~180L / min; L 上 L is the flow rate of the refining agent introduced into the upper part of the smelting furnace; 中 L is the flow rate of the refining agent introduced into the middle of the smelting furnace; 下 is the flow rate of the refining agent introduced into the lower part of the smelting furnace; and / or, The pressure of the refining agent satisfies the following conditions: P 下 =P 中 +0.2~0.4MPa=P 上 +0.3~0.6MPa; among which, P 上 P is the pressure of the refining agent introduced into the upper part of the smelting furnace; 中 P is the pressure of the refining agent introduced into the middle of the smelting furnace; 下 is the pressure of the refining agent introduced into the lower part of the smelting furnace; The conditions of the melt casting process include: a casting temperature of 720-760°C, a casting speed of 42-58 mm / min, a casting water flow rate of 28-42 m 3 / h, the electromagnetic stirring frequency is 8-15Hz; the first product obtained by the melt-casting process is an aluminum alloy cast rod, and the diameter of the aluminum alloy cast rod is ≥600mm.

9. The method according to claim 5, characterized in that In step S2, the plastic extrusion process includes a first-stage extrusion process and a second-stage extrusion process performed sequentially; wherein, The conditions of the first-stage extrusion treatment include: extrusion temperature of 440-475°C, extrusion speed of 14-20 m / min, and extrusion ratio of 32-50; The conditions of the second-stage extrusion treatment include: an extrusion temperature of 425-460° C., an extrusion speed of 4-10 m / min, and an extrusion ratio of 14-28.

10. The method according to claim 5, characterized in that In step S3, the conditions of the heating solution treatment include: a heating temperature of 430-460° C. and a heating time of 9-16 hours; The cryogenic treatment conditions include: the cryogenic medium includes liquid nitrogen at a temperature of -165°C to -130°C, and the treatment time is 2 to 8 hours; The conditions of the aging treatment include: a temperature of 150-180° C. and a heat preservation time of 4-12 hours.

11. An aluminum alloy product prepared according to the method according to any one of claims 5 to 10.

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