CN110218885B

CN110218885B - High-strength and high-toughness extrusion casting aluminum alloy and preparation method thereof

Info

Publication number: CN110218885B
Application number: CN201910546698.XA
Authority: CN
Inventors: 陈学文
Original assignee: Guangdong Engineering Polytechnic
Current assignee: Guangdong Engineering Polytechnic
Priority date: 2019-06-24
Filing date: 2019-06-24
Publication date: 2020-08-14
Anticipated expiration: 2039-06-24
Also published as: CN110218885A

Abstract

The invention discloses a high-strength and high-toughness extrusion casting aluminum alloy and a preparation method thereof. The high-strength and high-toughness extrusion casting aluminum alloy is prepared by the following preparation method, and comprises the following steps: 1) heating and melting the aluminum alloy waste into aluminum alloy liquid; 2) refining and modifying the aluminum alloy liquid; 3) degassing and impurity removing treatment is carried out on the aluminum alloy liquid; 4) extruding and casting the aluminum alloy liquid into aluminum alloy; 5) carrying out solution treatment on the extrusion casting aluminum alloy; 6) and carrying out aging treatment on the extrusion casting aluminum alloy. The invention directly prepares the high-strength and high-toughness extrusion casting aluminum alloy by taking the aluminum alloy waste aluminum as the main raw material, improves the use value of the waste aluminum, reduces the production cost of the extrusion casting aluminum alloy, has the advantages of high strength and good plasticity, can be used for extrusion casting and forming various aluminum alloy parts, and has wide application prospect.

Description

High-strength and high-toughness extrusion casting aluminum alloy and preparation method thereof

Technical Field

The invention belongs to the technical field of metal materials, and particularly relates to a high-strength and high-toughness extrusion casting aluminum alloy and a preparation method thereof.

Background

With the development of light weight of automobiles, a large number of automobile parts need to be replaced by aluminum instead of steel, and the aim of light weight of the automobiles is achieved. The parts belong to stressed structural members of safety systems on automobiles, so the development of light weight of the automobiles has higher requirements on the strength and plasticity of the aluminum alloy parts, so that the safety of the automobiles is improved, and the service life of the automobiles is prolonged. Squeeze casting is a technique in which molten metal is solidified and formed under the direct action of squeezing force. Extrusion casting is very suitable for producing high-strength aluminum alloy automobile parts. However, the existing aluminum alloy for extrusion casting generally has the problems of low strength and poor plasticity.

The existing extrusion casting aluminum alloy is prepared by mainly using pure aluminum as a main raw material and adding alloy elements such as silicon, magnesium, copper, zinc, manganese, cobalt and the like in the smelting casting process. As is known, pure aluminum is obtained by electrolyzing aluminum oxide, and the electrolysis of aluminum oxide belongs to the high energy consumption industry, and needs to consume a large amount of power resources, and in addition, the exploitation of aluminum ore resources, the production of aluminum oxide and the production of alloy elements such as silicon, magnesium, copper, zinc, manganese, cobalt and the like result in the production of extrusion casting aluminum alloy by the existing method, a large amount of coal power resources are consumed, and simultaneously, a large amount of carbon dioxide, dust and solid waste are discharged, so that the production cost of extrusion casting aluminum alloy is increased, and serious environmental pollution is caused.

China is a large country for producing and consuming aluminum alloy, a large amount of aluminum alloy needs to be consumed every year, and simultaneously, a large amount of waste aluminum is continuously generated every year, such as a large amount of process waste, stub bars, leftover materials, cutting materials and the like generated in the production and manufacturing processes of various aluminum and aluminum alloy products, and waste aluminum such as aluminum and aluminum alloy castings, pipe bar profiles, plate band foils and the like which are recovered after scrapping in the fields of buildings, automobiles, motorcycles, electronic appliances, packaging and the like.

The waste aluminum is used for regenerating the high-strength and high-toughness extrusion casting aluminum alloy, so that the production cost of the extrusion casting aluminum alloy can be reduced, and the consumption of a large amount of coal power resources and the emission of carbon dioxide, dust and solid wastes can be reduced. However, most of the aluminum scraps in China are mainly used for regenerating casting aluminum alloys for hardware products with low added values, and metal elements such as silicon, magnesium, copper, zinc, manganese, cobalt and the like contained in the aluminum scraps are not effectively utilized, so that a great deal of precious metal elements are wasted. Therefore, the method for directly regenerating the high-toughness extrusion casting aluminum alloy by using the waste aluminum has very important significance for realizing energy conservation and emission reduction and environmental protection in the casting aluminum industry, improving the use value of the waste aluminum and reducing the production cost of the extrusion casting aluminum alloy.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention aims to provide a high-strength and high-toughness extrusion casting aluminum alloy and a preparation method thereof. The high strength and toughness of the invention means that the tensile strength of the extrusion casting aluminum alloy is more than or equal to 400MPa, the yield strength is more than or equal to 370MPa, and the elongation after fracture is more than or equal to 10%.

The invention takes the waste aluminum as the main raw material, directly regenerates the high-strength and high-toughness extrusion casting aluminum alloy by optimizing and designing the composition of the waste aluminum and carrying out refinement and modification treatment, improves the use value of the waste aluminum and reduces the production cost of the extrusion casting aluminum alloy.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the invention provides a preparation method of a high-strength and high-toughness extrusion casting aluminum alloy, which comprises the following steps:

1) heating and melting 4xxx series aluminum alloy waste, 5xxx series aluminum alloy waste, 2xxx series aluminum alloy waste, 7xxx series aluminum alloy waste and 3xxx series aluminum alloy waste to form aluminum alloy liquid;

2) adding an aluminum-zirconium-boron intermediate alloy, an aluminum-antimony intermediate alloy and an aluminum-vanadium intermediate alloy into the aluminum alloy liquid to carry out refinement and modification treatment;

3) degassing and removing impurities of the aluminum alloy liquid, slagging off and standing;

4) extruding and casting the aluminum alloy liquid subjected to degassing and impurity removal treatment into aluminum alloy;

5) heating the extrusion casting aluminum alloy, then quenching, and carrying out solid solution treatment;

6) carrying out aging treatment on the extrusion casting aluminum alloy after the solution treatment to obtain high-strength and high-toughness extrusion casting aluminum alloy;

the preparation raw materials of the high-strength and high-toughness extrusion casting aluminum alloy comprise the following components in percentage by mass: 75 to 80 percent of 4xxx series aluminum alloy scrap, 12 to 15.1 percent of 5xxx series aluminum alloy scrap, 3 to 5 percent of 2xxx series aluminum alloy scrap, 2 to 4 percent of 7xxx series aluminum alloy scrap, 1 to 3 percent of 3xxx series aluminum alloy scrap, 0.2 to 0.4 percent of aluminum-zirconium-boron intermediate alloy, 0.1 to 0.2 percent of aluminum-antimony intermediate alloy and 0.1 to 0.2 percent of aluminum-vanadium intermediate alloy.

In the preparation method of the high-strength and high-toughness extrusion casting aluminum alloy, the used aluminum alloy waste materials are described as follows:

the 4xxx aluminum alloy scrap is an aluminum alloy scrap taking silicon as a main alloy element, and the scrap has wide sources, including process scrap generated in the production process of various 4xxx aluminum alloys and various discarded and recycled 4xxx aluminum alloy parts. Preferably, the 4xxx series aluminum alloy scrap consists of the following components in percentage by mass: 8.0 to 9.0 percent of Si, 0.1 to 0.4 percent of Mg0.2 to 0.5 percent of Mn0.6 percent of Fe, less than or equal to 0.1 percent of single impurity element, less than or equal to 0.5 percent of total impurity element and the balance of Al.

The 5xxx series aluminum alloy waste is aluminum alloy waste taking magnesium as a main alloy element, and the waste aluminum has wide sources, including scrap heads, leftover materials and scraps generated in the production process of the 5xxx series aluminum alloy, and profiles, pipes, bars and plates which are recycled after being scrapped. Preferably, the 5xxx series aluminum alloy scrap consists of the following components in percentage by mass: 4.0 to 5.0 percent of Mg, 0.4 to 1.0 percent of Mn0.1 to 0.3 percent of Co, less than or equal to 0.4 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total impurity element and the balance of Al.

The 2xxx aluminum alloy waste is aluminum alloy waste aluminum with copper as a main alloy element, and the waste aluminum has wide sources, including scrap heads, leftover materials and scraps generated in the processing process of the 2xxx aluminum alloy, and 2xxx aluminum alloy sections, tubes, bars and plates recovered after being scrapped. Preferably, the 2xxx series aluminum alloy scrap consists of the following components in percentage by mass: 3.5 to 4.5 percent of Cu, 0.4 to 1.0 percent of Mg0, 0.4 to 1.0 percent of Mn, 0.2 to 0.8 percent of Si, less than or equal to 0.7 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total impurity element, and the balance of Al.

The 7xxx aluminum alloy waste is aluminum alloy waste aluminum with zinc as a main alloy element, and the waste aluminum has wide sources, including scrap heads, leftover materials and scraps generated in the production process of the 7xxx aluminum alloy, and 7xxx aluminum alloy sections, pipes, bars and plates recovered after being scrapped. Preferably, the 7xxx series aluminum alloy scrap consists of the following components in percentage by mass: 5.5 to 6.5 percent of Zn, 2.0 to 3.0 percent of Mg, 2.0 to 3.0 percent of Cu, less than or equal to 0.2 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total impurity element and the balance of Al.

The 3xxx aluminum alloy waste is aluminum alloy waste aluminum with manganese as a main alloy element, and the waste aluminum has wide sources, including scrap heads, leftover materials and scraps generated in the processing process of the 3xxx aluminum alloy, and 3xxx aluminum alloy sections, pipes, bars and plates recovered after being scrapped. Preferably, the 3xxx series aluminum alloy scrap consists of the following components in percentage by mass: 1.0 to 1.5 percent of Mn, 0.05 to 0.2 percent of Mg, less than or equal to 0.7 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total amount of impurity elements and the balance of Al.

Preferably, in the preparation method of the high-strength and high-toughness squeeze casting aluminum alloy, the composition of each intermediate alloy is as follows:

the aluminum-zirconium-boron intermediate alloy comprises the following components in percentage by mass: 4.8 to 5.2 percent of Zr, 0.8 to 1.2 percent of B, less than or equal to 0.2 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total amount of impurity elements and the balance of Al;

the aluminum-antimony master alloy comprises the following components in percentage by mass: 24.5 to 25.5 percent of Sb, less than or equal to 0.2 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total amount of impurity elements and the balance of Al;

the aluminum-vanadium intermediate alloy comprises the following components in percentage by mass: 9.5 to 10.5 percent of V, less than or equal to 0.2 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total amount of impurity elements and the balance of Al.

Preferably, in the step 1) of the preparation method of the high-strength and high-toughness extrusion casting aluminum alloy, the heating and melting temperature is 740-780 ℃.

In the preparation method of the high-strength and high-toughness squeeze casting aluminum alloy, in the step 1), when the waste aluminum material is heated and melted into the aluminum alloy liquid, the aluminum alloy liquid needs to be fully stirred in order to improve the uniformity of the components of the aluminum alloy liquid and prevent the segregation of alloy elements; if an aluminum melting furnace with a permanent magnet stirring at the bottom is selected for heating and melting, the common knowledge of the technical personnel in the field of aluminum alloy casting in the field is provided.

In the step 2) of the preparation method of the high-strength and high-toughness extrusion casting aluminum alloy, the aluminum-zirconium-boron intermediate alloy is added for refining alpha-A crystal grains, improving casting fluidity and structure uniformity and improving strength and plasticity; the purpose of adding the aluminum-antimony intermediate alloy is to refine and deteriorate coarse needle-shaped eutectic Si phase, eliminate the damage to plasticity and toughness and improve the strength of the extrusion casting aluminum alloy; the aim of adding the aluminum-vanadium intermediate alloy is to refine the coarse and large needle-shaped iron-rich phase and improve the strength, plasticity, corrosion resistance and heat resistance of the extrusion casting aluminum alloy.

Preferably, the preparation method of the high-strength and high-toughness squeeze casting aluminum alloy comprises the following step 3) specifically: and (3) blowing and refining the aluminum alloy liquid for 10-15 minutes by adopting protective gas and refining agent to perform degassing and deslagging treatment, and standing for 30-60 minutes after deslagging.

Preferably, in the step 3) of the preparation method of the high-strength and high-toughness squeeze casting aluminum alloy, the protective gas is selected from one or more of argon, helium, neon and nitrogen; further preferably, the protective gas is selected from argon or nitrogen.

Preferably, in the step 3) of the preparation method of the high-strength and high-toughness squeeze casting aluminum alloy, the purity of the protective gas is more than or equal to 99.99 percent.

Preferably, in the step 3) of the preparation method of the high-strength and high-toughness squeeze casting aluminum alloy, the dosage of the refining agent accounts for 0.3-0.5 percent of the total mass of the preparation raw materials.

The aluminum alloy liquid is refined, degassed and decontaminated by adopting the aluminum alloy refining agent containing sodium salt, so that the phenomenon of sodium brittleness of the extrusion casting aluminum alloy is easily caused, and the strength and the plasticity of the extrusion casting aluminum alloy are reduced. The invention preferably adopts a sodium-free refining agent, and the sodium-free refining agent does not contain NaCl, NaF and Na₂CO₃And the like. Sodium-free refining agents are common feedstocks in the art.

In the step 4), the extrusion casting is a casting forming process method for solidifying and forming the aluminum alloy liquid under the direct action of extrusion force. Extrusion casting is a common aluminum alloy casting technique in the industrial field at present, and the specific process conditions are conventional technical means.

Preferably, in the step 4) of the preparation method of the high-strength and high-toughness squeeze casting aluminum alloy, the temperature of squeeze casting is 680-720 ℃, and the pressure of squeeze casting is 60-100 MPa.

In the step 5) of the preparation method of the high-strength and high-toughness squeeze casting aluminum alloy, the solution treatment refers to a heat treatment process of heating the squeeze casting aluminum alloy to a certain high-temperature area for constant temperature and heat preservation, fully dissolving metal elements such as silicon, magnesium, copper, zinc, manganese, chromium and the like and excess phases in the squeeze casting aluminum alloy into an aluminum matrix, and then rapidly cooling the aluminum matrix in modes such as quenching and the like to obtain a supersaturated solid solution.

In the step 5) of the preparation method of the high-strength and high-toughness extrusion casting aluminum alloy, the quenching is a process of transferring the extrusion casting aluminum alloy after heating and heat preservation into water for cooling. After a large amount of experimental researches, the inventor finds that after the extrusion casting aluminum alloy is heated for 3 to 5 hours at the temperature of between 515 and 525 ℃, water quenching is carried out, so that metal elements and excess phases can be fully dissolved into an aluminum matrix to obtain a supersaturated solid solution, and ideal structure performance can be obtained after aging.

Preferably, in the step 5) of the preparation method of the high-strength and high-toughness extrusion casting aluminum alloy, in order to ensure the quenching effect, the transfer time of the extrusion casting aluminum alloy is not more than 10 seconds; the water temperature of the quenching water is 50-100 ℃.

In the step 6) of the preparation method of the high-strength and high-toughness extrusion casting aluminum alloy, the aging treatment is a heat treatment process for heating the extrusion casting aluminum alloy to a certain temperature region and keeping the temperature at a constant temperature, and is an important means for improving the mechanical property and the physical property of the extrusion casting aluminum alloy. After a large amount of experimental researches, the inventor discovers that the high-strength and high-toughness extrusion casting aluminum alloy can be obtained by adopting a two-stage aging process, namely heating the extrusion casting aluminum alloy at 120-130 ℃ for 3-4 hours, then heating the extrusion casting aluminum alloy to 160-170 ℃ for 2-3 hours, and then cooling the extrusion casting aluminum alloy along with a furnace.

The invention also provides the high-strength and high-toughness extrusion casting aluminum alloy prepared by the preparation method.

The high-strength and high-toughness extrusion casting aluminum alloy consists of the following components in percentage by mass: 6.01 to 7.24 percent of Si, 0.61 to 1.22 percent of Mg0.15 to 0.33 percent of Cu, 0.11 to 0.26 percent of Zn, 0.22 to 0.65 percent of Mn, 0.012 to 0.045 percent of Co, 0.025 to 0.051 percent of Sb, 0.01 to 0.021 percent of Zr, 0.002 to 0.005 percent of B, 0.01 to 0.021 percent of V, less than or equal to 0.7 percent of Fe, less than or equal to 0.1 percent of single content of impurity elements, less than or equal to 0.5 percent of total content of impurity elements and the balance of Al; preferably, the high-strength and high-toughness extrusion casting aluminum alloy consists of the following components in percentage by mass: 6.27 to 7.24 percent of Si, 0.71 to 1.22 percent of Mg, 0.15 to 0.33 percent of Cu, 0.11 to 0.26 percent of Zn, 0.36 to 0.59 percent of Mn0.012 to 0.045 percent of Co, 0.025 to 0.051 percent of Sb, 0.01 to 0.021 percent of Zr, 0.002 to 0.005 percent of B, 0.01 to 0.021 percent of V, less than or equal to 0.66 percent of Fe, less than or equal to 0.1 percent of single content of impurity elements, less than or equal to 0.5 percent of total content of impurity elements and the balance of Al.

In the extrusion casting aluminum alloy and the preparation raw material thereof, the impurity elements refer to other inevitable elements in the extrusion casting aluminum alloy/aluminum alloy scrap/intermediate alloy.

The effects of the elements of the squeeze cast aluminum alloy of the present invention are further described below:

si is the main alloying element of extrusion cast aluminum alloys, and Si and Al can form A firstl + Si eutectic liquid phase, and improves the casting fluidity of the alloy. Si can also form Mg with Mg₂In addition, when the eutectic Si phase is in a fine and uniform granular shape or a short fiber shape and is dispersed and distributed on the α -Al matrix, the strength, the heat resistance and the machining performance of the extrusion casting aluminum alloy can be improved.

Mg has the solid solution strengthening function in the extrusion casting aluminum alloy and can form Mg with Si₂Si strengthening phase, further enhancing the strength of the squeeze cast aluminum alloy. The higher the Mg content, the higher the strength of the aluminum alloy, but too high a Mg content causes a decrease in plasticity.

Cu can form CuAl with Al in extrusion casting aluminum alloy₂Strengthening phase to strengthen the strength of the aluminum alloy. The strength of the squeeze cast aluminum alloy is difficult to reach 400MPa because the Cu content is too low. The higher the Cu content, the higher the strength of the squeeze cast aluminum alloy, but it also increases the tendency of the squeeze cast aluminum alloy to crack and reduces the corrosion resistance of the squeeze cast aluminum alloy.

Zn can form an Al + Zn eutectic liquid phase in the extrusion casting aluminum alloy, so that the casting fluidity of the alloy is improved, and the hot cracking tendency is reduced. In addition, Zn and Mg can also form MgZn₂Strengthening phase to strengthen the strength of the extrusion casting aluminum alloy. However, too high a Zn content also reduces the plasticity of the squeeze cast aluminum alloy.

Mn and Co belong to transition group elements, and can be directly dissolved into an aluminum matrix, so that the bonding force among aluminum atoms is increased, the diffusion process of the aluminum atoms and the decomposition speed of a solid solution are reduced, and the thermal stability of the extrusion casting aluminum alloy is improved. Secondly, Mn and Co can also form MnAl with Al₆、CoAl₇And MnCoAl₁₂The multiple dispersion strengthening phases are distributed on the aluminum matrix and the crystal boundary, so that the migration and dislocation movement of the crystal boundary and the sub-crystal boundary are hindered, the resistance of the dislocation movement in the aluminum matrix is increased, the rheology of the crystal boundary at high temperature is hindered, and the high-temperature stability of the extrusion casting aluminum alloy is improved. The content of Mn and Co is too low, the effect is not obvious, the content is too high, and coarse intermetallic compounds are easily formed to deteriorate the mechanical property of the extrusion casting aluminum alloy.

The function of Sb isRefining the modified eutectic Si phase. Si in addition to forming Mg₂In addition to the Si strengthening phase, most of the Si is present in the squeeze cast aluminum alloy as eutectic Si, which, when in the form of generally coarse needle-like shapes, can severely crack the aluminum matrix and reduce the strength, particularly the plasticity and toughness, of the squeeze cast aluminum alloy. By adding the Sb into the Al-Sb intermediate alloy, the eutectic Si phase is obviously refined and modified, and the coarse needle-like eutectic Si is converted into fine and uniform particles or short fibers and is dispersed on an aluminum matrix, so that the damage to the plasticity and the toughness of the aluminum matrix can be eliminated, and the strength of the extrusion casting aluminum alloy is improved. The Sb content is too low to give sufficient refining and modification effects.

Zr and B are added into the extrusion casting aluminum alloy liquid in the form of aluminum-zirconium-boron intermediate alloy, and mainly have the functions of refining grains, improving casting fluidity and structure uniformity and improving strength and plasticity. Although the traditional AlTiB master alloy is a very effective grain refiner for aluminum grains, in the extrusion casting aluminum alloy containing Mn and Co, the grain refining effect is poisoned by Mn and Co, so that the grain refining effect is lost. The inventor discovers through a large amount of experimental researches that the aluminum-zirconium-boron master alloy grain refiner has an immune effect on poisoning of Mn and Co, can obviously refine grain structures of extrusion casting aluminum alloy, improves casting fluidity and structure uniformity, and improves strength and plasticity.

The function of V is mainly to refine and deteriorate the coarse needle-like iron-rich phase. Fe is generally coarse acicular FeAl in squeeze casting aluminum alloy due to impurity element₃、FeSiAl₃In addition, the needle-like β -Fe iron-rich phase can form micro-galvanic corrosion with the aluminum matrix to reduce the corrosion resistance of the aluminum alloy, and the inventor conducts extensive experimental research on the problem and finds that the additive element V can be adsorbed on FeAl during the solidification process of the alloy₃、FeSiAl₃Equal iron-rich phase growth front, inhibition βThe acicular growth of the Fe-rich phase finally converts the coarse acicular β -Fe-rich phase into fine uniform granular α -Fe-rich phase which is dispersed and distributed in the aluminum matrix, eliminates the harm of the coarse acicular β -Fe-rich phase to the strength, plasticity and corrosion resistance of the extrusion casting aluminum alloy, and improves the strength, plasticity and corrosion resistance of the extrusion casting aluminum alloy₁₂The (FeSiV) phase is distributed on the grain boundary to prevent crystal sliding and hinder the rheology of the grain boundary at high temperature, thereby improving the heat resistance of the extrusion casting aluminum alloy.

The invention has the beneficial effects that:

the invention takes the waste aluminum as the main raw material, directly prepares the high-toughness extrusion casting aluminum alloy by optimizing and designing the composition of the waste aluminum and refining modification treatment, not only improves the use value of the waste aluminum, but also reduces the production cost of the extrusion casting aluminum alloy, and the prepared extrusion casting aluminum alloy has the advantages of high strength and good plasticity, can be used for extrusion casting and forming various aluminum alloy parts, and has wide application prospect.

Compared with the prior art, the invention has the following advantages:

(1) the invention takes the waste aluminum as a main raw material, optimally designs the composition of the waste aluminum, adds a small amount of aluminum-zirconium-boron, aluminum-antimony and aluminum-vanadium intermediate alloy for refining and modification treatment, directly regenerates the high-strength and high-toughness extrusion casting aluminum alloy with high added value, does not use pure aluminum, and does not additionally add metal elements such as silicon, magnesium, copper, zinc, manganese, cobalt and the like, thereby improving the use value of the waste aluminum, reducing the production cost of the extrusion casting aluminum alloy by at least 20 percent compared with the production cost of the prior art, and simultaneously promoting the energy conservation, emission reduction and environmental protection of the casting aluminum industry.

(2) According to the invention, a large amount of metal elements such as silicon, magnesium, copper, zinc, manganese, cobalt and the like contained in the waste aluminum are fully utilized, the composition of the waste aluminum is scientifically optimized and designed, and a small amount of aluminum-zirconium-boron, aluminum-antimony and aluminum-vanadium intermediate alloy is added for refining modification treatment, so that the elements are mutually matched to generate solid solution strengthening, precipitation strengthening and dispersed phase strengthening, the hazards of large needle-shaped eutectic silicon phase and iron-rich phase to the strength, plasticity and corrosion resistance of the aluminum alloy are eliminated, and the strength, plasticity, corrosion resistance and heat resistance of the extrusion casting aluminum alloy are obviously improved.

(3) The extrusion casting aluminum alloy has the tensile strength of more than or equal to 400MPa, the yield strength of more than or equal to 370MPa and the elongation after fracture of more than or equal to 10 percent, has higher strength and plasticity, can be used for extrusion casting and forming various structural parts, and has wide application prospect.

Detailed Description

The present invention will be described in further detail with reference to specific examples. The starting materials used in the examples are, unless otherwise specified, commercially available from conventional sources.

Example 1

The high-strength and high-toughness extrusion casting aluminum alloy of the embodiment comprises the following raw materials in percentage by mass: 75% of a 4xxx series aluminum alloy scrap, 15.1% of a 5xxx series aluminum alloy scrap, 4.3% of a 2xxx series aluminum alloy scrap, 2.6% of a 7xxx series aluminum alloy scrap, 2.5% of a 3xxx series aluminum alloy scrap, 0.2% of an aluminum-zirconium-boron master alloy, 0.1% of an aluminum-antimony master alloy, and 0.2% of an aluminum-vanadium master alloy.

The raw materials comprise the following chemical components in percentage by mass:

the 4xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 8.51 percent of Si, 0.26 percent of Mg, 0.37 percent of Mn0.6 percent of Fe, less than or equal to 0.6 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.1 percent individually, and the total content is less than or equal to 0.5 percent;

the 5xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 4.54 percent of Mg, 0.59 percent of Mn, 0.28 percent of Co0.4 percent or less of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.05 percent individually, and the total amount is less than or equal to 0.15 percent;

the 2xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 3.51 percent of Cu, 0.88 percent of Mg, 0.53 percent of Mn0.32 percent of Si, less than or equal to 0.7 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 7xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 6.45 percent of Zn, 2.84 percent of Mg, 2.25 percent of Cu2, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.05 percent individually, and the total content is less than or equal to 0.15 percent;

the 3xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 1.32 percent of Mn, 0.15 percent of Mg, less than or equal to 0.7 percent of Fe, the balance of Al and inevitable other impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-zirconium-boron intermediate alloy comprises the following chemical components in percentage by mass: 4.99 percent of Zr, 1.02 percent of B, less than or equal to 0.2 percent of Fe, and the balance of Al and inevitable other impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-antimony master alloy comprises the following chemical components in percentage by mass: sb 24.98 percent, Fe is less than or equal to 0.2 percent, the balance is Al and other inevitable impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-vanadium intermediate alloy comprises the following chemical components in percentage by mass: 10.12 percent of V, less than or equal to 0.2 percent of Fe, and the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent.

The preparation method of the high-strength and high-toughness extrusion casting aluminum alloy comprises the following steps:

the first step is as follows: heating and melting the 4xxx series aluminum alloy waste, the 5xxx series aluminum alloy waste, the 2xxx series aluminum alloy waste, the 7xxx series aluminum alloy waste and the 3xxx series aluminum alloy waste into aluminum alloy liquid at 740 ℃;

the second step is that: adding an aluminum-zirconium-boron, aluminum-antimony and aluminum-vanadium intermediate alloy into the aluminum alloy liquid for refining and modification treatment;

the third step: blowing and refining the aluminum alloy liquid for 15 minutes by using nitrogen with the purity of 99.99 percent and sodium-free refining agent accounting for 0.3 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, and standing for 30 minutes after slagging off;

the fourth step: extruding and casting the aluminum alloy liquid subjected to degassing and impurity removal treatment into aluminum alloy by using a metal mold under the conditions that the temperature is 680 ℃ and the pressure is 100 MPa;

the fifth step: heating the extrusion casting aluminum alloy at 515 ℃ for 5 hours, then quenching for solid solution treatment, wherein the transfer time of the extrusion casting aluminum alloy is 10 seconds, and the water temperature of the quenching is 100 ℃;

and a sixth step: heating the extrusion casting aluminum alloy after the solution treatment at 125 ℃ for 3.5 hours, then continuously heating to 165 ℃ for 3 hours for aging treatment, and cooling along with the furnace to obtain the high-strength and high-toughness extrusion casting aluminum alloy.

Example 2

The high-strength and high-toughness extrusion casting aluminum alloy of the embodiment comprises the following raw materials in percentage by mass: 78% of a 4xxx series aluminum alloy scrap, 15% of a 5xxx series aluminum alloy scrap, 3% of a 2xxx series aluminum alloy scrap, 2% of a 7xxx series aluminum alloy scrap, 1.3% of a 3xxx series aluminum alloy scrap, 0.4% of an aluminum zirconium boron master alloy, 0.2% of an aluminum antimony master alloy, and 0.1% of an aluminum vanadium master alloy.

the 4xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 8.01 percent of Si, 0.39 percent of Mg, 0.24 percent of Mn0.6 percent of Fe, less than or equal to 0.6 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.1 percent individually, and the total content is less than or equal to 0.5 percent;

the 5xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 4.02 percent of Mg, 0.95 percent of Mn, 0.30 percent of Co0, less than or equal to 0.4 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.05 percent individually, and the total content is less than or equal to 0.15 percent;

the 2xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 3.50 percent of Cu, 0.80 percent of Mg, 0.55 percent of Mn0.63 percent of Si, less than or equal to 0.7 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 7xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 5.50 percent of Zn, 2.61 percent of Mg, 2.26 percent of Cu2, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.05 percent individually, and the total amount is less than or equal to 0.15 percent;

the 3xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 1.35 percent of Mn, 0.16 percent of Mg, less than or equal to 0.7 percent of Fe, the balance of Al and inevitable other impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-zirconium-boron intermediate alloy comprises the following chemical components in percentage by mass: 5.2 percent of Zr, 1.2 percent of B, less than or equal to 0.2 percent of Fe, the balance of Al and inevitable other impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-antimony master alloy comprises the following chemical components in percentage by mass: 25.5 percent of Sb, less than or equal to 0.2 percent of Fe, and the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-vanadium intermediate alloy comprises the following chemical components in percentage by mass: 9.5 percent of V, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, the single content of other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent.

the first step is as follows: heating and melting the 4xxx series aluminum alloy scrap, the 5xxx series aluminum alloy scrap, the 2xxx series aluminum alloy scrap, the 7xxx series aluminum alloy scrap and the 3xxx series aluminum alloy scrap into aluminum alloy liquid at 750 ℃;

the third step: blowing and refining the aluminum alloy liquid for 13 minutes by using argon with the purity of 99.99 percent and sodium-free refining agent accounting for 0.4 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, slagging off and then standing for 50 minutes;

the fourth step: extruding and casting the aluminum alloy liquid subjected to degassing and impurity removal treatment into aluminum alloy by using a metal mold under the conditions that the temperature is 690 ℃ and the pressure is 60 MPa;

the fifth step: heating the extrusion casting aluminum alloy at 520 ℃ for 4 hours, then quenching for solid solution treatment, wherein the transfer time of the extrusion casting aluminum alloy is 10 seconds, and the water temperature of the quenching is 70 ℃;

and a sixth step: heating the extrusion casting aluminum alloy after the solution treatment at 125 ℃ for 3.5 hours, then continuously heating to 165 ℃ for 2.5 hours for aging treatment, and cooling along with the furnace to obtain the high-strength and high-toughness extrusion casting aluminum alloy.

Example 3

The high-strength and high-toughness extrusion casting aluminum alloy of the embodiment comprises the following raw materials in percentage by mass: 80% of a 4xxx series aluminum alloy scrap, 12% of a 5xxx series aluminum alloy scrap, 4% of a 2xxx series aluminum alloy scrap, 2% of a 7xxx series aluminum alloy scrap, 1.3% of a 3xxx series aluminum alloy scrap, 0.4% of an aluminum zirconium boron master alloy, 0.2% of an aluminum antimony master alloy, and 0.1% of an aluminum vanadium master alloy.

the 4xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 8.9 percent of Si, 0.2 percent of Mg, 0.5 percent of Mn, less than or equal to 0.6 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.1 percent, and the total content is less than or equal to 0.5 percent;

the 5xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 4.5 percent of Mg, 0.9 percent of Mn, 0.2 percent of Co, less than or equal to 0.4 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 2xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 3.5 percent of Cu, 1.0 percent of Mg, 0.5 percent of Mn, 0.7 percent of Si, less than or equal to 0.7 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 7xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 6.5 percent of Zn, 3.0 percent of Mg, 2.1 percent of Cu, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.05 percent individually, and the total content is less than or equal to 0.15 percent;

the 3xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 1.5 percent of Mn, 0.05 percent of Mg, less than or equal to 0.7 percent of Fe, the balance of Al and inevitable other impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-zirconium-boron intermediate alloy comprises the following chemical components in percentage by mass: 4.8 percent of Zr, 1.2 percent of B, less than or equal to 0.2 percent of Fe, the balance of Al and inevitable other impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-antimony master alloy comprises the following chemical components in percentage by mass: 24.5 percent of Sb, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-vanadium intermediate alloy comprises the following chemical components in percentage by mass: 9.9 percent of V, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, the single content of other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent.

the first step is as follows: heating and melting the 4xxx series aluminum alloy scrap, the 5xxx series aluminum alloy scrap, the 2xxx series aluminum alloy scrap, the 7xxx series aluminum alloy scrap and the 3xxx series aluminum alloy scrap into aluminum alloy liquid at 780 ℃;

the third step: blowing and refining the aluminum alloy liquid for 10 minutes by using argon with the purity of 99.99 percent and sodium-free refining agent accounting for 0.5 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, slagging off and then standing for 60 minutes;

the fourth step: extruding and casting the aluminum alloy liquid subjected to degassing and impurity removal treatment into aluminum alloy by using a metal mold under the conditions that the temperature is 720 ℃ and the pressure is 80 MPa;

the fifth step: heating the extrusion casting aluminum alloy at 525 ℃ for 3 hours, then quenching for solid solution treatment, wherein the transfer time of the extrusion casting aluminum alloy is 10 seconds, and the water temperature of the quenching is 50 ℃;

and a sixth step: heating the extrusion casting aluminum alloy after the solution treatment at 130 ℃ for 3 hours, then continuously heating to 170 ℃ for 2 hours for aging treatment, and cooling along with the furnace to obtain the high-strength high-toughness extrusion casting aluminum alloy.

Example 4

The high-strength and high-toughness extrusion casting aluminum alloy of the embodiment comprises the following raw materials in percentage by mass: 77% of a 4xxx series aluminum alloy scrap, 13% of a 5xxx series aluminum alloy scrap, 4% of a 2xxx series aluminum alloy scrap, 3% of a 7xxx series aluminum alloy scrap, 2.4% of a 3xxx series aluminum alloy scrap, 0.3% of an aluminum zirconium boron master alloy, 0.15% of an aluminum antimony master alloy, and 0.15% of an aluminum vanadium master alloy.

the 4xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 8.6 percent of Si, 0.3 percent of Mg, 0.4 percent of Mn, less than or equal to 0.6 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.1 percent, and the total content is less than or equal to 0.5 percent;

the 5xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 4.4 percent of Mg, 0.8 percent of Mn, 0.2 percent of Co, less than or equal to 0.4 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 2xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 3.8 percent of Cu, 0.6 percent of Mg, 0.8 percent of Mn, 0.5 percent of Si, less than or equal to 0.7 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 7xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 6.1 percent of Zn, 2.5 percent of Mg, 2.3 percent of Cu, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.05 percent individually, and the total content is less than or equal to 0.15 percent;

the 3xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 1.3 percent of Mn, 0.1 percent of Mg, less than or equal to 0.7 percent of Fe, the balance of Al and inevitable other impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-zirconium-boron intermediate alloy comprises the following chemical components in percentage by mass: 5 percent of Zr, 1 percent of B, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, the single content of other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-antimony master alloy comprises the following chemical components in percentage by mass: 25 percent of Sb, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, the single content of other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-vanadium intermediate alloy comprises the following chemical components in percentage by mass: v10 percent, Fe is less than or equal to 0.2 percent, the balance is Al and other inevitable impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent.

the first step is as follows: heating and melting the 4xxx series aluminum alloy waste, the 5xxx series aluminum alloy waste, the 2xxx series aluminum alloy waste, the 7xxx series aluminum alloy waste and the 3xxx series aluminum alloy waste into aluminum alloy liquid at 760 ℃;

the third step: blowing and refining the aluminum alloy liquid for 12 minutes by using argon with the purity of 99.99 percent and sodium-free refining agent accounting for 0.4 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, and standing for 40 minutes after slagging off;

the fourth step: extruding and casting the aluminum alloy liquid subjected to degassing and impurity removal treatment into aluminum alloy by using a metal mold under the conditions that the temperature is 700 ℃ and the pressure is 90 MPa;

the fifth step: heating the extrusion casting aluminum alloy at 520 ℃ for 4 hours, then quenching for solid solution treatment, wherein the transfer time of the extrusion casting aluminum alloy is 10 seconds, and the water temperature of the quenching is 80 ℃;

Example 5

The high-strength and high-toughness extrusion casting aluminum alloy of the embodiment comprises the following raw materials in percentage by mass: 80% of a 4xxx series aluminum alloy scrap, 12% of a 5xxx series aluminum alloy scrap, 4.5% of a 2xxx series aluminum alloy scrap, 2% of a 7xxx series aluminum alloy scrap, 1% of a 3xxx series aluminum alloy scrap, 0.2% of an aluminum zirconium boron master alloy, 0.1% of an aluminum antimony master alloy, and 0.2% of an aluminum vanadium master alloy.

the 4xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 9.0 percent of Si, 0.4 percent of Mg, 0.5 percent of Mn, less than or equal to 0.6 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.1 percent, and the total content is less than or equal to 0.5 percent;

the 5xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 5.0 percent of Mg, 1.0 percent of Mn, 0.10 percent of Co, less than or equal to 0.4 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 2xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 3.5 percent of Cu, 1.0 percent of Mg, 1.0 percent of Mn, 0.8 percent of Si, less than or equal to 0.7 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 7xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 6.5 percent of Zn, 3.0 percent of Mg, 2.0 percent of Cu, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 3xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 1.5 percent of Mn, 0.2 percent of Mg, less than or equal to 0.7 percent of Fe, the balance of Al and inevitable other impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-zirconium-boron intermediate alloy comprises the following chemical components in percentage by mass: 4.8 percent of Zr, 0.8 percent of B, less than or equal to 0.2 percent of Fe, the balance of Al and inevitable other impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-vanadium intermediate alloy comprises the following chemical components in percentage by mass: v10.5 percent, Fe is less than or equal to 0.2 percent, the balance is Al and other inevitable impurity elements, the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent.

the first step is as follows: heating and melting the 4xxx series aluminum alloy scrap, the 5xxx series aluminum alloy scrap, the 2xxx series aluminum alloy scrap, the 7xxx series aluminum alloy scrap and the 3xxx series aluminum alloy scrap into aluminum alloy liquid at 770 ℃;

the third step: blowing and refining the aluminum alloy liquid for 15 minutes by using nitrogen with the purity of 99.99 percent and sodium-free refining agent accounting for 0.3 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, slagging off and then standing for 60 minutes;

the fourth step: extruding and casting the aluminum alloy liquid subjected to degassing and impurity removal treatment into aluminum alloy by using a metal mold under the conditions that the temperature is 710 ℃ and the pressure is 70 MPa;

the fifth step: heating the extrusion casting aluminum alloy at 515 ℃ for 5 hours, then quenching for solid solution treatment, wherein the transfer time of the extrusion casting aluminum alloy is 10 seconds, and the water temperature of the quenching is 60 ℃;

and a sixth step: heating the extrusion casting aluminum alloy after the solution treatment at 130 ℃ for 3 hours, then continuously heating to 160 ℃ for 2 hours for aging treatment, and cooling along with the furnace to obtain the high-strength high-toughness extrusion casting aluminum alloy.

Example 6

The high-strength and high-toughness extrusion casting aluminum alloy of the embodiment comprises the following raw materials in percentage by mass: 75% of a 4xxx series aluminum alloy scrap, 15% of a 5xxx series aluminum alloy scrap, 4.6% of a 2xxx series aluminum alloy scrap, 4% of a 7xxx series aluminum alloy scrap, 1% of a 3xxx series aluminum alloy scrap, 0.2% of an aluminum zirconium boron master alloy, 0.1% of an aluminum antimony master alloy, and 0.1% of an aluminum vanadium master alloy.

the 5xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 5.0 percent of Mg, 1.0 percent of Mn, 0.3 percent of Co, less than or equal to 0.4 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 2xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 4.5 percent of Cu, 1.0 percent of Mg, 1.0 percent of Mn, 0.8 percent of Si, less than or equal to 0.7 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of each other impurity element is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the 7xxx series aluminum alloy waste comprises the following chemical components in percentage by mass: 6.5 percent of Zn, 3.0 percent of Mg, 3.0 percent of Cu3.0 percent, less than or equal to 0.2 percent of Fe, the balance of Al and other inevitable impurity elements, wherein the content of the other impurity elements is less than or equal to 0.05 percent individually, and the total amount is less than or equal to 0.15 percent;

the aluminum-zirconium-boron intermediate alloy comprises the following chemical components in percentage by mass: 5.02 percent of Zr, 1.12 percent of B, less than or equal to 0.2 percent of Fe, and the balance of Al and inevitable other impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-antimony master alloy comprises the following chemical components in percentage by mass: 25.3 percent of Sb, less than or equal to 0.2 percent of Fe, and the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent;

the aluminum-vanadium intermediate alloy comprises the following chemical components in percentage by mass: 10.1 percent of V, less than or equal to 0.2 percent of Fe, and the balance of Al and other inevitable impurity elements, wherein the single content of the other impurity elements is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent.

the third step: blowing and refining the aluminum alloy liquid for 10 minutes by using argon with the purity of 99.99 percent and sodium-free refining agent accounting for 0.5 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, slagging off and then standing for 30 minutes;

and a sixth step: heating the extrusion casting aluminum alloy after the solution treatment at 120 ℃ for 4 hours, then continuously heating to 170 ℃ for 2 hours for aging treatment, and cooling along with the furnace to obtain the high-strength high-toughness extrusion casting aluminum alloy.

The extruded and cast aluminum alloys prepared in examples 1 to 6 were subjected to chemical composition analysis on an ARL-4600 type photoelectric direct-reading spectrometer, and the analysis results are shown in Table 1.

TABLE 1 EXAMPLES 1-6 chemical composition of squeeze cast aluminum alloys

According to the national standard GB/T16865-2013 sample and method for tensile test of wrought aluminum, magnesium and alloy processing products thereof, the extrusion casting aluminum alloy prepared in the embodiment 1-6 is processed into a standard tensile sample, the standard tensile sample is stretched on a DNS200 type electronic tensile testing machine at room temperature, the tensile speed is 2mm/min, the tensile strength, the yield strength and the elongation after fracture of the extrusion casting aluminum alloy are detected, and the detection results are shown in Table 2.

TABLE 2 tensile mechanical Properties at Room temperature for the extrusion cast aluminum alloys of examples 1-6

	Tensile strength/MPa	Yield strength/MPa	Elongation after break/%
				Example 1	403.5	371.9	12.8
Example 2	412.6	384.6	11.9
				Example 3	423.5	391.5	10.8
Example 4	409.1	374.8	12.5
				Example 5	431.2	395.8	10.4
Example 6	419.1	386.1	11.5

As can be seen from Table 2, the tensile strength of the squeeze casting aluminum alloy prepared by the invention is more than or equal to 400MPa, the yield strength is more than or equal to 370MPa, and the elongation after fracture is more than or equal to 10 percent, which shows that the squeeze casting aluminum alloy prepared by the invention has higher strength and plasticity.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A preparation method of high-strength and high-toughness extrusion casting aluminum alloy is characterized by comprising the following steps: the method comprises the following steps:

the preparation raw materials of the high-strength and high-toughness extrusion casting aluminum alloy comprise the following components in percentage by mass: 75-80% of 4xxx series aluminum alloy waste, 12-15.1% of 5xxx series aluminum alloy waste, 3-5% of 2xxx series aluminum alloy waste, 2-4% of 7xxx series aluminum alloy waste, 1-3% of 3xxx series aluminum alloy waste, 0.2-0.4% of aluminum-zirconium-boron intermediate alloy, 0.1-0.2% of aluminum-antimony intermediate alloy and 0.1-0.2% of aluminum-vanadium intermediate alloy;

the extrusion casting aluminum alloy comprises the following components in percentage by mass: 6.01 to 7.24 percent of Si, 0.61 to 1.22 percent of Mg, 0.15 to 0.33 percent of Cu, 0.11 to 0.26 percent of Zn, 0.22 to 0.65 percent of Mn, 0.012 to 0.045 percent of Co, 0.025 to 0.051 percent of Sb, 0.01 to 0.021 percent of Zr, 0.002 to 0.005 percent of B, 0.01 to 0.021 percent of V, less than or equal to 0.7 percent of Fe, less than or equal to 0.1 percent of single content of impurity elements, less than or equal to 0.5 percent of total content of impurity elements and the balance of Al.

2. The method of claim 1, wherein: the composition of each aluminum alloy waste is as follows:

the 4xxx series aluminum alloy scrap consists of the following components in percentage by mass: 8.0 to 9.0 percent of Si, 0.1 to 0.4 percent of Mg, 0.2 to 0.5 percent of Mn, less than or equal to 0.6 percent of Fe, less than or equal to 0.1 percent of single impurity element, less than or equal to 0.5 percent of total impurity element and the balance of Al; the 5xxx series aluminum alloy scrap consists of the following components in percentage by mass: 4.0 to 5.0 percent of Mg, 0.4 to 1.0 percent of Mn, 0.1 to 0.3 percent of Co, less than or equal to 0.4 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total impurity element and the balance of Al; the 2xxx series aluminum alloy waste consists of the following components in percentage by mass: 3.5 to 4.5 percent of Cu, 0.4 to 1.0 percent of Mg0, 0.4 to 1.0 percent of Mn, 0.2 to 0.8 percent of Si, less than or equal to 0.7 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total impurity element, and the balance of Al;

the 7xxx series aluminum alloy scrap consists of the following components in percentage by mass: 5.5 to 6.5 percent of Zn, 2.0 to 3.0 percent of Mg, 2.0 to 3.0 percent of Cu, less than or equal to 0.2 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total impurity element and the balance of Al; the 3xxx series aluminum alloy scrap consists of the following components in percentage by mass: 1.0 to 1.5 percent of Mn, 0.05 to 0.2 percent of Mg0.7 percent of Fe, less than or equal to 0.05 percent of single impurity element, less than or equal to 0.15 percent of total amount of impurity elements and the balance of Al.

3. The method of claim 1, wherein: the composition of each master alloy is as follows:

4. The method of claim 1, wherein: in the step 1), the heating and melting temperature is 740-780 ℃.

5. The method of claim 1, wherein: the step 3) is specifically as follows: and (3) blowing and refining the aluminum alloy liquid for 10-15 minutes by adopting protective gas and refining agent to perform degassing and deslagging treatment, and standing for 30-60 minutes after deslagging.

6. The method of claim 5, wherein: in the step 3), the protective gas is selected from one or more of argon, helium, neon and nitrogen; the dosage of the refining agent accounts for 0.3 to 0.5 percent of the total mass of the preparation raw materials.

7. The method of claim 1, wherein: in the step 4), the temperature of extrusion casting is 680-720 ℃, and the pressure of extrusion casting is 60-100 MPa.

8. The method of claim 1, wherein: step 5) heating the extrusion casting aluminum alloy at 515-525 ℃ for 3-5 hours and then quenching; the transfer time of the squeeze cast aluminum alloy is not more than 10 seconds; the water temperature of the quenching water is 50-100 ℃.

9. The method of claim 1, wherein: in the step 6), the aging treatment is to heat the extrusion casting aluminum alloy for 3 to 4 hours at 120 to 130 ℃, and then heat the extrusion casting aluminum alloy for 2 to 3 hours at 160 to 170 ℃.

10. The high-strength and high-toughness extrusion casting aluminum alloy prepared by the preparation method of any one of claims 1 to 9, which is characterized in that: