CN112921195A

CN112921195A - Method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum

Info

Publication number: CN112921195A
Application number: CN202110097271.3A
Authority: CN
Inventors: 付亚城; 王顺成; 蒙继海; 王辉
Original assignee: Foshan Chenhui Metal Technology Co ltd
Current assignee: Foshan Chenhui Metal Technology Co ltd
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2021-06-08
Anticipated expiration: 2041-01-25
Also published as: CN112921195B

Abstract

The invention relates to a method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum, belonging to the technical field of aluminum alloy preparation. The method takes the aluminum alloy waste as the main raw material to prepare the cast aluminum-silicon alloy with high strength and wear resistance, reduces the production cost of the cast aluminum-silicon alloy, and the cast aluminum-silicon alloy consists of the following components in percentage by mass: 12.02 to 14.48 percent of Si, 1.22 to 2.44 percent of Cu, 0.30 to 0.66 percent of Mg, 0.22 to 0.52 percent of Ti, 0.22 to 0.65 percent of Fe, 0.012 to 0.045 percent of Cr, 0.025 to 0.051 percent of Ba, 0.01 to 0.021 percent of Ni, 0.002 to 0.005 percent of C, 0.01 to 0.021 percent of B, and the balance of Al and inevitable impurities. The cast aluminum-silicon alloy has high strength and excellent wear resistance, and is suitable for casting and molding various aluminum alloy parts with higher requirements on strength and wear resistance.

Description

Method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum

Technical Field

The invention belongs to the technical field of aluminum alloy preparation, and particularly relates to a method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum.

Background

The cast aluminum-silicon alloy has excellent casting fluidity, machining performance and wear resistance, and is widely applied to casting parts with complex shapes and structures, such as engine cylinders, cylinder sleeves, pistons, brake blocks, belt wheels, gear pump bearings and the like, in the fields of automobiles, motorcycles, agricultural implements, electric tools and the like. With the development of light weight of automobiles, motorcycles, agricultural implements, electric tools and the like, parts are also continuously developed to thin walls and light weight, and cast aluminum-silicon alloy is required to have higher strength, plasticity and wear resistance, so that the problems of low strength, poor plasticity and insufficient wear resistance of the existing cast aluminum-silicon alloy are increasingly highlighted.

The reasons that the existing cast aluminum-silicon alloy has low strength, poor plasticity and insufficient wear resistance include the following: firstly, because the content of Si is high, the Si exists together in the form of needle-shaped eutectic Si and coarse primary Si in the cast aluminum-silicon alloy, and the needle-shaped eutectic Si and the coarse primary Si belong to hard brittle phases and can also seriously crack an aluminum matrix, thereby reducing the strength, plasticity and wear resistance of the cast aluminum-silicon alloy. Secondly, the content of Fe in the cast aluminum-silicon alloy is high, Fe usually exists in the cast aluminum-silicon alloy matrix in the form of coarse needle-shaped Al-Fe-Si system Fe-rich phase in the aluminum-silicon alloy, and the coarse needle-shaped Fe-rich phase belongs to a hard and brittle intermetallic compound phase and can seriously crack the aluminum matrix to become a crack source and a crack propagation direction for the stress fracture of the cast aluminum-silicon alloy.

In addition, the existing cast aluminum-silicon alloy is mainly prepared by taking pure aluminum as a main raw material and adding alloy elements such as silicon, magnesium, copper and the like in the smelting and 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 and the like cause that the existing method for producing cast aluminum-silicon alloy needs to consume a large amount of coal power resources, and simultaneously discharges a large amount of carbon dioxide, dust and solid wastes, thereby not only increasing the production cost of cast aluminum-silicon alloy, but also causing serious environmental pollution.

China is a large country for producing and consuming aluminum alloy, a large amount of aluminum alloy needs to be consumed every year, and meanwhile, a large amount of aluminum alloy waste materials, such as aluminum alloy parts, profiles, pipes, plates and the like which are recycled after being scrapped in the fields of buildings, automobiles, motorcycles, ships, airplanes, electronic appliances and the like, and a large amount of aluminum alloy leftover materials, cutting scraps and the like generated in the production process are continuously generated every year. The cast aluminum-silicon alloy is prepared by utilizing the aluminum alloy waste material, so that the production cost of the cast aluminum-silicon alloy can be reduced, and the consumption of a large amount of coal power resources and the discharge of carbon dioxide, dust and solid waste can be reduced. Therefore, the method for preparing the cast aluminum-silicon alloy by using the aluminum alloy waste has very important significance for realizing energy conservation and emission reduction and environmental protection in the cast aluminum industry, improving the use value of the aluminum alloy waste and reducing the production cost of the cast aluminum-silicon alloy. Therefore, the existing preparation method of casting aluminum-silicon alloy still needs to be improved and developed.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a method for preparing high-strength wear-resistant cast aluminum-silicon alloy by utilizing waste aluminum.

In order to achieve the above purpose, the present invention is realized by the following means:

the invention provides a method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum, which comprises the following steps:

(1) selecting aluminum-silicon alloy waste as a raw material, and heating and melting the waste to form aluminum-silicon alloy liquid;

(2) adding an aluminum-nickel-carbon alloy, an aluminum-barium alloy and an aluminum-boron alloy into the aluminum-silicon alloy liquid for refining and modification treatment;

(3) blowing and refining the aluminum-silicon alloy liquid by using inert gas and an aluminum alloy refining agent to carry out degassing and impurity removal treatment, slagging off and then standing;

(4) casting the aluminum-silicon alloy liquid subjected to degassing and impurity removal treatment into aluminum-silicon alloy by using a metal mold;

(5) heating cast aluminum-silicon alloy, and then quenching to perform solid solution treatment;

(6) heating the cast aluminum-silicon alloy after the solution treatment for 1-2 hours, then cooling, continuing to heat for 2-3 hours for aging treatment, and cooling along with the furnace to obtain the high-strength wear-resistant cast aluminum-silicon alloy.

Preferably, the aluminum-silicon alloy scrap consists of the following components in percentage by mass: 16.0 to 18.0 percent of Si, 0.2 to 0.8 percent of Cu, 0.2 to 0.5 percent of Fe, the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount of impurities is less than or equal to 0.15 percent. The aluminum-silicon alloy waste material is an aluminum alloy waste material taking element silicon as a main alloy element, and the aluminum-silicon alloy waste material has wide sources, such as various scrapped and recycled engine cylinders, pistons and the like of automobiles and motorcycles.

Preferably, the raw material in step (1) further comprises one or more selected from the group consisting of aluminum copper alloy scrap, aluminum magnesium alloy scrap, aluminum titanium alloy scrap and aluminum iron alloy scrap.

More preferably, the aluminum-copper alloy scrap consists of the following components in percentage by mass: 8.0 to 10.0 percent of Cu, 0.4 to 1.0 percent of Fe, 0.1 to 0.3 percent of Cr, the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount of impurities is less than or equal to 0.15 percent.

More preferably, the aluminum magnesium alloy scrap comprises the following components in percentage by mass: 7.0 to 9.0 percent of Mg, 0.8 to 2.0 percent of Cu, 0.4 to 1.0 percent of Fe, 0.4 to 1.6 percent of Si, the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total content of impurities is less than or equal to 0.15 percent.

More preferably, the aluminum-titanium alloy scrap consists of the following components in percentage by mass: 11.0 to 13.0 percent of Ti, 4.0 to 6.0 percent of Cu, 4.0 to 6.0 percent of Mg, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount of impurities is less than or equal to 0.15 percent.

More preferably, the aluminum-iron alloy scrap consists of the following components in percentage by mass: 1.0 to 1.5 percent of Fe, 0.1 to 0.4 percent of Cu, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount of impurities is less than or equal to 0.15 percent.

The aluminum-copper alloy waste is an aluminum alloy waste with element copper as a main alloy element, and the aluminum-copper alloy waste has wide sources, such as various plates, sections, forgings, bars and the like generated after scrapping of airplanes.

The aluminum magnesium alloy waste is an aluminum alloy waste with magnesium as a main alloy element, and the aluminum magnesium alloy waste has wide sources, such as scrapped and recycled ship plates, pressure containers, refrigerated containers, television towers and the like.

The aluminum-titanium alloy waste is an aluminum alloy waste with titanium as a main alloy element, and the aluminum-titanium alloy waste has wide sources, such as various scrapped and recycled aluminum-titanium alloy parts in the fields of airplanes, submarines and weaponry.

The aluminum-iron alloy waste is an aluminum alloy waste with element iron as a main alloy element, and the aluminum-iron alloy waste has wide sources, such as various scrapped and recycled aluminum-iron alloy wires, aluminum-iron alloy plates and the like.

In the step (1), in order to reduce energy consumption for heating and melting and reduce production cost, an energy-saving and environment-friendly aluminum melting furnace should be selected, the heating and melting temperature cannot be too low, otherwise, the melting speed is low, the production efficiency is low, the temperature is not too high, and otherwise, the oxidation loss of aluminum is easily caused. In addition, in order to improve the uniformity of the components of the aluminum alloy liquid and prevent the segregation of alloy elements, the aluminum alloy liquid needs to be fully stirred, for example, an aluminum melting furnace with a permanent magnet stirring bottom is selected for heating and melting, which is common knowledge of technicians in the field of aluminum alloy casting.

Preferably, the raw material comprises the following components in percentage by mass based on the total mass of the raw material: 75-80% of aluminum-silicon alloy waste, 12-15.1% of aluminum-copper alloy waste, 3-5% of aluminum-magnesium alloy waste, 2-4% of aluminum-titanium alloy waste and 1-3% of aluminum-iron alloy waste.

Preferably, the heating temperature in step (1) is 760-780 ℃.

Preferably, the mass percentages of the aluminum-nickel-carbon alloy, the aluminum-barium alloy and the aluminum-boron alloy in the step (2) are respectively 0.2-0.4%, 0.1-0.2% and 0.1-0.2% based on the total mass of the raw materials.

More preferably, the aluminum-nickel-carbon alloy consists of the following components in percentage by mass: 4.8 to 5.2 percent of Ni, 0.8 to 1.2 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount of impurities is less than or equal to 0.15 percent.

More preferably, the aluminum barium alloy consists of the following components in percentage by mass: 24.5 to 25.5 percent of Ba, the balance of Al and inevitable impurities, the content of single impurity is less than or equal to 0.05 percent, and the total amount of impurities is less than or equal to 0.15 percent.

More preferably, the aluminum boron alloy consists of the following components in percentage by mass: 9.5 to 10.5 percent of B, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount of impurities is less than or equal to 0.15 percent.

In the step (2), the aluminum-nickel-carbon 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-barium alloy is to refine and deteriorate the thick needle-shaped eutectic Si phase, eliminate the damage to plasticity and toughness and improve the strength, plasticity and wear resistance of the cast aluminum-silicon alloy; the purpose of adding the aluminum-boron alloy is to refine and modify the coarse needle-shaped iron-rich phase and improve the strength, plasticity and wear resistance of the cast aluminum-silicon alloy.

Preferably, the inert gas in step (3) is selected from one or more of nitrogen or argon, more preferably argon with a purity of 99.9%; the adding amount of the aluminum alloy refining agent is 0.3-0.5% of the total mass of the raw materials.

Preferably, the aluminum alloy refining agent in the step (3) includes C₂Cl₆，K₃AlF₆，CaCO₃，K₂SO₄，MgSO₄，KF，NaF，CaCl₂(ii) a More preferably, the aluminum alloy refining agent consists of the following components in percentage by mass: c₂Cl₆45.3%，K₃AlF₆ 14.1%，CaCO₃ 9.5%，K₂SO₄ 15.9%，MgSO₄4.1%，KF 2.3%，NaF 5.6%，CaCl₂3.2 percent; most preferably, the aluminum alloy refining agent is used in an amount of 0.3 to 0.5% by mass of the aluminum alloy liquid.

Preferably, the blowing refining time in the step (3) is 20 to 30 minutes, and the standing time is 10 to 20 minutes.

The blowing refining is to spray a granular aluminum alloy refining agent into the aluminum-silicon alloy liquid by using inert gas as a current-carrying medium through a powder sprayer so that the refining agent is in full contact reaction with the aluminum-silicon alloy liquid, and then the gas and impurities in the aluminum-silicon alloy liquid are adsorbed and taken away, thereby achieving the purposes of degassing, removing impurities and purifying. The inert gas can be nitrogen or argon, and because the nitrogen reacts with aluminum in the high-temperature aluminum-silicon alloy liquid to generate aluminum nitride to influence the quality of the aluminum-silicon alloy liquid, the inert gas is preferably argon with the purity of more than or equal to 99.9 percent.

Because the waste aluminum alloy material is often mixed with a large amount of water, grease, paint, organic coatings and the like, the gas content and the inclusion content of the aluminum-silicon alloy liquid are higher, and the refining, degassing and impurity removal treatment of the aluminum-silicon alloy liquid becomes more difficult. Aiming at the problems of high liquid impurity content and difficult degassing and impurity removal of aluminum-silicon alloy, the inventor discovers that the composition of a refining agent has an important influence on the degassing and impurity removal effects of refining through the research on an aluminum alloy refining agent, and the main composition of the aluminum alloy refining agent sold in the market at present is C₂Cl₆KF, NaF and CaCl₂And C is₂Cl₆The content of the aluminum alloy is low, no fluoroaluminate, carbonate and sulfate are contained, or the content of the aluminum alloy is low, the degassing and impurity removing effects of the refining agent are poor, and the aluminum alloy liquid with high cleanliness is difficult to obtain. After a great deal of experimental research, the inventor finds that the performance of the cast aluminum-silicon alloy is improved by adjusting the composition of the existing aluminum alloy refining agent, removing partial chloride salt and fluoride salt, increasing the content of hexachloroethane and adding potassium fluoroaluminate, calcium carbonate, potassium sulfate and magnesium sulfate, wherein the reason is that the hexachloroethane, the potassium fluoroaluminate, the calcium carbonate, the potassium sulfate and the magnesium sulfateThe magnesium sulfate can react with the high-temperature aluminum-silicon alloy liquid to release more bubbles, so that more hydrogen ions and impurities can be adsorbed and carried, and better refining, degassing and impurity removing effects are achieved.

The inventor researches and discovers that the using amount of the refining agent cannot be too small, the refining time cannot be too short, otherwise, the ideal refining degassing and impurity removing effect cannot be achieved, the using amount of the refining agent cannot be too large, otherwise, the production cost is increased, the refining time cannot be too long, and otherwise, the aluminum-silicon alloy liquid can be excessively oxidized. According to the invention, by strictly controlling the usage amount of the refining agent and the blowing refining time, the degassing and impurity removal can be relatively thoroughly carried out, the pure aluminum-silicon alloy liquid is obtained, the influence of air holes and inclusion defects on the performance of the cast aluminum-silicon alloy is eliminated, and the strength and the plasticity of the cast aluminum-silicon alloy are improved.

Preferably, in the step (4), the aluminum-silicon alloy liquid after degassing and impurity removing treatment is cast into the aluminum-silicon alloy by a metal mold under the condition of 690-710 ℃. In the step, the casting temperature is not suitable to be too low, otherwise, the fluidity of the aluminum-silicon alloy liquid is poor, and the casting is not smooth or the molding is incomplete easily caused.

Preferably, the heating temperature in step (5) is 495-505 ℃, and the heating time is 1-2 hours.

Preferably, in the solution treatment of the quenching water in the step (5), the transfer time of the cast aluminum-silicon alloy is less than or equal to 5 seconds, and the water temperature of the quenching water is 20-40 ℃.

In the step (5), the solution treatment refers to a heat treatment process of heating the cast aluminum-silicon alloy to a certain high-temperature region for constant temperature preservation, so that metal elements such as silicon, magnesium, copper and the like and excess phases in the cast aluminum-silicon alloy are fully dissolved 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. The water quenching is a process of transferring the cast aluminum-silicon alloy after heating and heat preservation into water for cooling. After a great deal of experimental research, the inventor finds that the casting aluminum-silicon alloy is heated at 495-505 ℃ for 1-2 hours and then quenched, 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. In order to ensure the quenching effect, the transfer time of the cast aluminum-silicon alloy is optimally less than or equal to 5 seconds, and the water temperature of the quenching is 20-40 ℃.

Preferably, in the step (6), the cast aluminum-silicon alloy after the solution treatment is heated at the temperature of 160-170 ℃, and then is cooled to the temperature of 140-150 ℃ for further heating and aging treatment.

In the step (6), the aging treatment is a heat treatment process for heating the cast aluminum-silicon 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 and chemical properties of the cast aluminum-silicon alloy. After a large amount of experimental researches, the inventor discovers that the high-strength wear-resistant cast aluminum-silicon alloy can be obtained by adopting a two-stage aging process, namely heating the cast aluminum-silicon alloy at the temperature of 160-170 ℃ for 1-2 hours, then cooling to the temperature of 140-150 ℃ and continuing heating for 2-3 hours, and then cooling along with the furnace.

The invention provides a high-strength wear-resistant cast aluminum-silicon alloy prepared by the method for preparing the high-strength wear-resistant cast aluminum-silicon alloy by utilizing the waste aluminum, which consists of the following components in percentage by weight: si, Cu, Mg, Ti, Fe, Cr, Ba, Ni, C, B, Al and inevitable impurities.

Preferably, the high-strength wear-resistant cast aluminum-silicon alloy consists of the following components in percentage by mass: 12.02 to 14.48 percent of Si, 1.22 to 2.44 percent of Cu, 0.30 to 0.66 percent of Mg, 0.22 to 0.52 percent of Ti, 0.22 to 0.65 percent of Fe, 0.012 to 0.045 percent of Cr, 0.025 to 0.051 percent of Ba, 0.01 to 0.021 percent of Ni, 0.002 to 0.005 percent of C, 0.01 to 0.021 percent of B, the balance of Al and inevitable impurities, wherein the single content of the impurities is less than or equal to 0.05 percent, and the total content of the impurities is less than or equal to 0.15 percent.

More preferably, the high-strength wear-resistant cast aluminum-silicon alloy consists of the following components in percentage by mass: 12.54 to 14.48 percent of Si, 1.42 to 2.44 percent of Cu, 0.30 to 0.66 percent of Mg, 0.22 to 0.52 percent of Ti, 0.36 to 0.59 percent of Fe, 0.012 to 0.045 percent of Cr, 0.025 to 0.051 percent of Ba, 0.01 to 0.021 percent of Ni, 0.002 to 0.005 percent of C, 0.01 to 0.021 percent of B, the balance of Al and inevitable impurities, wherein the single content of the impurities is less than or equal to 0.05 percent, and the total content of the impurities is less than or equal to 0.15 percent.

The function of each element in the high-strength wear-resistant cast aluminum-silicon alloy is explained as follows:

si is a main alloy element for casting the aluminum-silicon alloy, and firstly, the Si and the Al can form an Al + Si eutectic liquid phase, so that the casting fluidity of the aluminum-silicon alloy is improved. Secondly, Si can also form Mg with Mg₂The Si strengthening phase strengthens the strength of the cast aluminum-silicon alloy. Finally, when the Si phase is in a fine and uniform granular shape or a short fiber shape and is dispersed and distributed on the alpha-Al matrix, the wear resistance and the machining performance of the cast aluminum-silicon alloy can be greatly improved.

Cu has the solid solution strengthening function in casting aluminum-silicon alloy and can form Al with Al₂The Cu strengthening phase further enhances the strength of the cast aluminum-silicon alloy. The higher the Cu content, the higher the strength of the Al-Si alloy, but too high a Cu content causes a decrease in plasticity.

Mg not only has the solid solution strengthening function in casting aluminum-silicon alloy, but also can form Mg with Si₂The Si strengthening phase strengthens the strength of the aluminum-silicon alloy.

Ti forms mainly TiAl in casting Al-Si alloy₃The dispersed particle phase is dispersed and distributed on the aluminum matrix, which can hinder the growth of recrystallized grains, refine the recrystallized grains and improve the recrystallization temperature and the stability of high-temperature mechanical property of the cast aluminum-silicon alloy.

The main function of Fe in casting the aluminum-silicon alloy is to play a role in demoulding, which is beneficial to separating the aluminum alloy from a metal mould. In addition, when the Fe-rich phase is in a fine and uniform granular alpha-Fe-rich phase and is dispersed and distributed in the aluminum matrix, the strength and the wear resistance of the cast aluminum-silicon alloy can be improved.

Cr belongs to transition group elements, and can be directly dissolved in 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 solid solution are reduced, and the thermal stability of the cast aluminum-silicon alloy is improved. Secondly, Cr can also form CrAl with Al₃The dispersion strengthening phase is 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 cast aluminum-silicon alloy is improved.

Ba functions to refine the modified eutectic Si phase. Si in addition to forming Mg₂Outside the Si strengthening phase, most of the Si is present in the cast al-Si 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, especially the plasticity and toughness, of the cast al-Si alloy. The element Ba is introduced by adding the aluminum-barium alloy, so that the eutectic Si phase has obvious refining and modification effects, thick needle-like sheet eutectic Si can be converted into fine and uniform particles or short fibers and is dispersed and distributed on an aluminum matrix, the damage to plasticity and toughness can be eliminated, and the strength, wear resistance and machining performance of the cast aluminum-silicon alloy are improved.

Ni and C are added into the cast aluminum-silicon alloy liquid in the form of aluminum-nickel-carbon alloy, and mainly have the functions of refining grains, improving casting fluidity and structure uniformity and improving strength and plasticity. Although the conventional AlTiC master alloy is a very effective grain refiner for aluminum grains, in the cast aluminum-silicon alloy containing Si and Cr, the grain refining effect is poisoned by Si and Cr, and the grain refining effect is lost. The inventor finds that the aluminum-nickel-carbon alloy grain refiner has an immune effect on poisoning of Si and Cr through a large number of experimental researches, can obviously refine the grain structure of cast aluminum-silicon alloy, improves the casting fluidity and the structure uniformity, and improves the strength and the plasticity.

The function of B is mainly to refine and deteriorate coarse needle-shaped iron-rich phase. Since Fe is generally in the form of coarse needles in cast Al-Si alloys₃、FeSiAl₃The coarse needle-shaped beta-Fe iron-rich phases exist in the aluminum-silicon alloy, and the coarse needle-shaped beta-Fe iron-rich phases are hard and brittle phases, can seriously crack an aluminum matrix, become crack sources and crack propagation directions for the fracture of the cast aluminum-silicon alloy, and damage the strength and the plasticity of the cast aluminum-silicon alloy. The inventor conducts a large amount of experimental research on the problem and discovers that the addition of the element B can be adsorbed on FeAl in the solidification process of the alloy₃、FeSiAl₃The growth front edge of the iron-rich phase is equal, the acicular growth of the beta-Fe iron-rich phase is inhibited, and finally the thick acicular beta-Fe iron-rich phase can be converted into a fine uniform granular alpha-Fe iron-rich phase which is dispersed and distributed in the aluminum matrix, so that the danger of the strength and plasticity of the thick acicular beta-Fe iron-rich phase for casting the aluminum-silicon alloy can be eliminatedAnd the wear resistance and the machinability of the cast aluminum-silicon alloy can be improved.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention takes the aluminum alloy waste as the main raw material, optimizes the composition of the aluminum alloy waste, adds a small amount of aluminum nickel carbon alloy, aluminum barium alloy and aluminum boron alloy for refining modification treatment, directly regenerates the cast aluminum-silicon alloy with high strength and wear resistance, does not use pure aluminum, does not additionally add metal elements such as silicon, magnesium, copper and the like, improves the use value of the aluminum alloy waste, reduces the production cost of the cast aluminum-silicon alloy, can reduce the production cost by at least more than 20 percent compared with the prior art, and promotes the energy conservation, emission reduction and environmental protection of the cast aluminum industry.

(2) According to the invention, the large metal elements such as silicon, magnesium, copper and the like contained in the aluminum alloy waste are fully utilized, the composition of the aluminum alloy waste is scientifically optimized and designed, and a small amount of aluminum-nickel-carbon alloy, aluminum-barium alloy and aluminum-boron alloy are added for refining modification treatment, so that the elements are mutually matched to generate solid solution strengthening, precipitation strengthening and dispersed phase strengthening, the damage of large needle sheet eutectic silicon phase and iron-rich phase to the strength and plasticity of cast aluminum-silicon-gold is eliminated, and the strength, plasticity and wear resistance of the cast aluminum-silicon alloy are obviously improved.

(3) The cast aluminum-silicon alloy has room temperature tensile strength of more than 510MPa, elongation of more than 12 percent and wear rate of less than 0.17 multiplied by 10^-6g/m, has the advantages of high strength, good plasticity and excellent wear resistance, can be applied to casting parts with complex shapes and structures, and meets the development requirements of light weight of automobiles, motorcycles, agricultural implements, electric tools and the like.

Drawings

Fig. 1 is a microstructure of cast aluminum-silicon alloy of example 1 at 100 times magnification.

Fig. 2 is a microstructure of the cast aluminum-silicon alloy of example 1 at 500 times magnification.

Fig. 3 is a microstructure of the cast aluminum-silicon alloy of comparative example 1 at 100 times magnification.

Fig. 4 shows a microstructure of the cast aluminum-silicon alloy of comparative example 1 at 500 times magnification.

Fig. 5 is a microstructure of the cast aluminum-silicon alloy of comparative example 2 at 100 times magnification.

Fig. 6 is a microstructure of the cast aluminum-silicon alloy of comparative example 2 at 500 times magnification.

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

A method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum comprises the following steps:

(1) selecting 75 percent of aluminum-silicon alloy waste, 15.1 percent of aluminum-copper alloy waste, 4.3 percent of aluminum-magnesium alloy waste, 2.6 percent of aluminum-titanium alloy waste and 2.5 percent of aluminum-iron alloy waste which account for the total weight of the raw materials, heating and melting the raw materials at 770 ℃ to form aluminum-silicon alloy liquid, wherein the raw materials comprise the following chemical components in percentage by mass: the aluminum-silicon alloy waste comprises the following chemical components in percentage by mass: 17.02 percent of Si, 0.52 percent of Cu, 0.37 percent of Fe, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-copper alloy scrap comprises the following chemical components in percentage by mass: 9.08 percent of Cu, 0.59 percent of Fe, 0.28 percent of Cr, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent; the aluminum-magnesium alloy waste comprises the following chemical components in percentage by mass: 7.02 percent of Mg, 1.76 percent of Cu, 0.53 percent of Fe, 0.64 percent of Si, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-titanium alloy waste comprises the following chemical components in percentage by mass: 12.90 percent of Ti, 5.68 percent of Cu, 4.50 percent of Mg, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-iron alloy waste comprises the following chemical components in percentage by mass: 1.32 percent of Fe, 0.3 percent of Cu, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(2) adding an aluminum-nickel-carbon alloy accounting for 0.2 percent of the total weight of the raw materials, an aluminum-barium alloy accounting for 0.1 percent of the total weight of the raw materials and an aluminum-boron alloy accounting for 0.2 percent of the total weight of the raw materials into the aluminum-silicon alloy liquid for refining and modification treatment; wherein the aluminum-nickel-carbon alloy comprises the following chemical components in percentage by mass: 4.99 percent of Ni, 1.02 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-barium alloy comprises the following chemical components in percentage by mass: ba 24.98%, the balance being Al and inevitable impurities, the content of single impurity is less than or equal to 0.05%, the total amount is less than or equal to 0.15%; the aluminum-boron alloy comprises the following chemical components in percentage by mass: 10.12 percent of B, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(3) blowing and refining the aluminum-silicon alloy liquid for 30 minutes by using argon with the purity of 99.9 percent and an aluminum alloy 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 10 minutes after slagging off, wherein the aluminum alloy refining agent comprises the following components in percentage by mass: c₂Cl₆ 45.3%，K₃AlF₆ 14.1%，CaCO₃ 9.5%，K₂SO₄ 15.9%，MgSO₄4.1%，KF 2.3%，NaF 5.6%，CaCl₂ 3.2%；

(4) Casting the aluminum-silicon alloy liquid subjected to degassing and impurity removal treatment into aluminum-silicon alloy by using a metal mold at the temperature of 690 ℃;

(5) heating the cast aluminum-silicon alloy at 500 ℃ for 2 hours, and then quenching for solid solution treatment, wherein the transfer time of the cast aluminum-silicon alloy is 5 seconds, and the water temperature of the quenching is 30 ℃;

(6) heating the cast aluminum-silicon alloy after the solution treatment at 165 ℃ for 1.5 hours, then cooling to 145 ℃, continuing to heat for 3 hours for aging treatment, and cooling along with the furnace to obtain the high-strength wear-resistant cast aluminum-silicon alloy.

Example 2

(1) selecting aluminum-silicon alloy waste accounting for 78% of the total weight of raw materials, 15% of aluminum-copper alloy waste, 3% of aluminum-magnesium alloy waste, 2% of aluminum-titanium alloy waste and 1.3% of aluminum-iron alloy waste, heating and melting the waste at 760 ℃ to form aluminum-silicon alloy liquid, wherein the raw materials comprise the following chemical components in percentage by mass: the aluminum-silicon alloy waste comprises the following chemical components in percentage by mass: 16.02 percent of Si, 0.78 percent of Cu, 0.24 percent of Fe, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-copper alloy scrap comprises the following chemical components in percentage by mass: 4.02 percent of Cu, 1.9 percent of Fe, 0.30 percent of Cr, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-magnesium alloy waste comprises the following chemical components in percentage by mass: 7.0 percent of Mg, 1.60 percent of Cu, 0.55 percent of Fe, 1.26 percent of Si, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-titanium alloy waste comprises the following chemical components in percentage by mass: 11.0 percent of Ti, 5.22 percent of Cu, 4.52 percent of Mg, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-iron alloy waste comprises the following chemical components in percentage by mass: 1.35 percent of Fe, 0.32 percent of Cu, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(2) adding an aluminum-nickel-carbon alloy accounting for 0.4 percent of the total weight of the raw materials, an aluminum-barium alloy accounting for 0.2 percent of the total weight of the raw materials and an aluminum-boron alloy accounting for 0.1 percent of the total weight of the raw materials into the aluminum-silicon alloy liquid for refining and modification treatment; wherein the aluminum-nickel-carbon alloy comprises the following chemical components in percentage by mass: 5.2 percent of Ni, 1.2 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-barium alloy comprises the following chemical components in percentage by mass: 25.5 percent of Ba, the balance of Al and inevitable impurities, the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-boron alloy comprises the following chemical components in percentage by mass: 9.5 percent of B, the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(3) blowing and refining the aluminum-silicon alloy liquid for 25 minutes by using argon with the purity of 99.9 percent and an aluminum alloy 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 20 minutes after slagging off, wherein the aluminum alloy refining agent comprises the following components in percentage by mass: c₂Cl₆ 45.3%，K₃AlF₆ 14.1%，CaCO₃ 9.5%，K₂SO₄ 15.9%，MgSO₄4.1%，KF 2.3%，NaF 5.6%，CaCl₂ 3.2%；

(4) Casting the aluminum-silicon alloy liquid subjected to degassing and impurity removal treatment into aluminum-silicon alloy by using a metal mold at the temperature of 700 ℃;

(5) heating the cast aluminum-silicon alloy at 505 ℃ for 1 hour, then quenching for solid solution treatment, wherein the transfer time of the cast aluminum-silicon alloy is 3 seconds, and the water temperature of the quenching is 20 ℃;

(6) heating the cast aluminum-silicon alloy after the solution treatment at 170 ℃ for 1 hour, then cooling to 150 ℃, continuing to heat for 2.5 hours for aging treatment, and cooling along with the furnace to obtain the high-strength wear-resistant cast aluminum-silicon alloy.

Example 3

(1) selecting 80% of aluminum-silicon alloy waste, 12% of aluminum-copper alloy waste, 4% of aluminum-magnesium alloy waste, 2% of aluminum-titanium alloy waste and 1.3% of aluminum-iron alloy waste which account for the total weight of the raw materials, heating and melting the raw materials at 780 ℃ to form aluminum-silicon alloy liquid, wherein the chemical components and the mass percentage of the raw materials are as follows: the aluminum-silicon alloy waste comprises the following chemical components in percentage by mass: 17.8 percent of Si, 0.4 percent of Cu, 0.5 percent of Fe, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-copper alloy scrap comprises the following chemical components in percentage by mass: 9.0 percent of Cu, 0.9 percent of Fe, 0.2 percent of Cr, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-magnesium alloy waste comprises the following chemical components in percentage by mass: 7.0 percent of Mg, 2.0 percent of Cu, 0.5 percent of Fe, 1.4 percent of Si, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-titanium alloy waste comprises the following chemical components in percentage by mass: 13.0 percent of Ti, 6.0 percent of Cu, 4.2 percent of Mg, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-iron alloy waste comprises the following chemical components in percentage by mass: 1.5 percent of Fe, 0.1 percent of Cu, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(2) adding an aluminum-nickel-carbon alloy accounting for 0.4 percent of the total weight of the raw materials, an aluminum-barium alloy accounting for 0.2 percent of the total weight of the raw materials and an aluminum-boron alloy accounting for 0.1 percent of the total weight of the raw materials into the aluminum-silicon alloy liquid for refining and modification treatment; wherein the aluminum-nickel-carbon alloy comprises the following chemical components in percentage by mass: 4.8 percent of Ni, 1.2 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-barium alloy comprises the following chemical components in percentage by mass: 24.5 percent of Ba, the balance of Al and inevitable impurities, the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-boron alloy comprises the following chemical components in percentage by mass: 9.9 percent of B, the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(3) blowing and refining the aluminum-silicon alloy liquid for 20 minutes by using argon with the purity of 99.9 percent and an aluminum alloy refining agent accounting for 0.5 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, and standing for 15 minutes after slagging off, wherein the aluminum alloy refining agent comprises the following components in percentage by mass: c₂Cl₆ 45.3%，K₃AlF₆ 14.1%，CaCO₃ 9.5%，K₂SO₄ 15.9%，MgSO₄4.1%，KF 2.3%，NaF 5.6%，CaCl₂ 3.2%；

(4) Casting the aluminum-silicon alloy liquid subjected to degassing and impurity removal treatment into aluminum-silicon alloy by using a metal mold at the temperature of 710 ℃;

(5) heating cast aluminum-silicon alloy at 495 ℃ for 1.5 hours, then quenching for solid solution treatment, wherein the transfer time of the cast aluminum-silicon alloy is 4 seconds, and the water temperature of the quenching is 40 ℃;

(6) heating the cast aluminum-silicon alloy after the solution treatment at 160 ℃ for 2 hours, then cooling to 140 ℃, continuing to heat for 2 hours for aging treatment, and cooling along with the furnace to obtain the high-strength wear-resistant cast aluminum-silicon alloy.

Example 4

(1) selecting 77 percent of aluminum-silicon alloy waste, 13 percent of aluminum-copper alloy waste, 4 percent of aluminum-magnesium alloy waste, 3 percent of aluminum-titanium alloy waste and 2.4 percent of aluminum-iron alloy waste which account for the total weight of raw materials, heating and melting the raw materials at 770 ℃ to form aluminum-silicon alloy liquid, wherein the raw materials comprise the following chemical components in percentage by mass: the aluminum-silicon alloy waste comprises the following chemical components in percentage by mass: 17.2 percent of Si, 0.6 percent of Cu, 0.4 percent of Fe, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-copper alloy scrap comprises the following chemical components in percentage by mass: 8.8 percent of Cu, 0.8 percent of Fe, 0.2 percent of Cr, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-magnesium alloy waste comprises the following chemical components in percentage by mass: 7.6 percent of Mg, 1.2 percent of Cu, 0.8 percent of Fe, 1.0 percent of Si, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-titanium alloy waste comprises the following chemical components in percentage by mass: 12.2 percent of Ti, 5.0 percent of Cu, 4.6 percent of Mg, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-iron alloy waste comprises the following chemical components in percentage by mass: 1.3 percent of Fe, 0.2 percent of Cu, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; (ii) a

(2) Adding an aluminum-nickel-carbon alloy accounting for 0.3 percent of the total weight of the raw materials, an aluminum-barium alloy accounting for 0.15 percent of the total weight of the raw materials and an aluminum-boron alloy accounting for 0.15 percent of the total weight of the raw materials into the aluminum-silicon alloy liquid for refining and modification treatment; wherein the aluminum-nickel-carbon alloy comprises the following chemical components in percentage by mass: 5 percent of Ni, 1 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-barium alloy comprises the following chemical components in percentage by mass: 25 percent of Ba, the balance of Al and inevitable impurities, the content of single impurity is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent; the aluminum-boron alloy comprises the following chemical components in percentage by mass: b10%, the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05%, and the total amount is less than or equal to 0.15%;

(3) blowing and refining the aluminum-silicon alloy liquid for 25 minutes by using argon with the purity of 99.9 percent and an aluminum alloy 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 15 minutes after slagging off, wherein the aluminum alloy refining agent comprises the following components in percentage by mass: c₂Cl₆ 45.3%，K₃AlF₆ 14.1%，CaCO₃ 9.5%，K₂SO₄ 15.9%，MgSO₄4.1%，KF 2.3%，NaF 5.6%，CaCl₂ 3.2%；

(5) heating the cast aluminum-silicon alloy at 500 ℃ for 1 hour, then quenching for solid solution treatment, wherein the transfer time of the cast aluminum-silicon alloy is 5 seconds, and the water temperature of the quenching is 30 ℃;

(6) heating the cast aluminum-silicon alloy after the solution treatment at 165 ℃ for 1.5 hours, then cooling to 145 ℃, continuing to heat for 2.5 hours for aging treatment, and cooling along with the furnace to obtain the high-strength wear-resistant cast aluminum-silicon alloy.

Example 5

(1) selecting 80 percent of aluminum-silicon alloy waste, 12 percent of aluminum-copper alloy waste, 4.5 percent of aluminum-magnesium alloy waste, 2 percent of aluminum-titanium alloy waste and 1 percent of aluminum-iron alloy waste which account for the total weight of raw materials, heating and melting the raw materials at 780 ℃ to form aluminum-silicon alloy liquid, wherein the raw materials comprise the following chemical components in percentage by mass: the aluminum-silicon alloy waste comprises the following chemical components in percentage by mass: 18.0 percent of Si, 0.8 percent of Cu, 0.5 percent of Fe, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-copper alloy scrap comprises the following chemical components in percentage by mass: 10.0 percent of Cu, 1.0 percent of Fe, 0.10 percent of Cr, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-magnesium alloy waste comprises the following chemical components in percentage by mass: 7.0 percent of Mg, 2.0 percent of Cu, 1.0 percent of Fe, 1.6 percent of Si, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-titanium alloy waste comprises the following chemical components in percentage by mass: 13.0 percent of Ti, 6.0 percent of Cu, 4.0 percent of Mg, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-iron alloy waste comprises the following chemical components in percentage by mass: 1.5 percent of Fe, 0.4 percent of Cu, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(2) adding an aluminum-nickel-carbon alloy accounting for 0.2 percent of the total weight of the raw materials, an aluminum-barium alloy accounting for 0.1 percent of the total weight of the raw materials and an aluminum-boron alloy accounting for 0.2 percent of the total weight of the raw materials into the aluminum-silicon alloy liquid for refining and modification treatment; wherein the aluminum-nickel-carbon alloy comprises the following chemical components in percentage by mass: 4.8 percent of Ni, 0.8 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-barium alloy comprises the following chemical components in percentage by mass: 24.5 percent of Ba, the balance of Al and inevitable impurities, the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-boron alloy comprises the following chemical components in percentage by mass: 10.5 percent of B, the balance of Al and inevitable impurities, the single content of the impurities is less than or equal to 0.05 percent, and the total content is less than or equal to 0.15 percent

(3) Blowing and refining the aluminum-silicon alloy liquid for 30 minutes by using argon with the purity of 99.9 percent and an aluminum alloy 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 20 minutes after slagging off, wherein the aluminum alloy refining agent comprises the following components in percentage by mass: c₂Cl₆ 45.3%，K₃AlF₆ 14.1%，CaCO₃ 9.5%，K₂SO₄ 15.9%，MgSO₄4.1%，KF 2.3%，NaF 5.6%，CaCl₂ 3.2%；

(5) heating the cast aluminum-silicon alloy at 505 ℃ for 2 hours, and then quenching for solid solution treatment, wherein the transfer time of the cast aluminum-silicon alloy is 4 seconds, and the water temperature of the quenching is 20 ℃;

(6) heating the cast aluminum-silicon alloy after the solution treatment at 170 ℃ for 1 hour, then cooling to 140 ℃, continuing to heat for 2 hours for aging treatment, and cooling along with the furnace to obtain the high-strength wear-resistant cast aluminum-silicon alloy.

Example 6

(1) selecting 75 percent of aluminum-silicon alloy waste, 15 percent of aluminum-copper alloy waste, 4.6 percent of aluminum-magnesium alloy waste, 4 percent of aluminum-titanium alloy waste and 1 percent of aluminum-iron alloy waste which account for the total weight of the raw materials, heating and melting the raw materials at 760 ℃ to form aluminum-silicon alloy liquid, wherein the raw materials comprise the following chemical components in percentage by mass: the aluminum-silicon alloy waste comprises the following chemical components in percentage by mass: 18.0 percent of Si, 0.8 percent of Cu, 0.5 percent of Fe, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-copper alloy scrap comprises the following chemical components in percentage by mass: 10.0 percent of Cu, 1.0 percent of Fe, 0.3 percent of Cr, and the balance of Al and inevitable impurities, wherein the content of a single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-magnesium alloy waste comprises the following chemical components in percentage by mass: 9.0 percent of Mg, 2.0 percent of Cu, 1.0 percent of Fe, 1.6 percent of Si, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-titanium alloy waste comprises the following chemical components in percentage by mass: 13.0 percent of Ti, 6.0 percent of Cu, 6.0 percent of Mg, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-iron alloy waste comprises the following chemical components in percentage by mass: 1.5 percent of Fe, 0.4 percent of Cu, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(2) adding an aluminum-nickel-carbon alloy accounting for 0.2 percent of the total weight of the raw materials, an aluminum-barium alloy accounting for 0.1 percent of the total weight of the raw materials and an aluminum-boron alloy accounting for 0.1 percent of the total weight of the raw materials into the aluminum-silicon alloy liquid for refining and modification treatment; wherein the aluminum-nickel-carbon alloy comprises the following chemical components in percentage by mass: 5.02 percent of Ni, 1.12 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-barium alloy comprises the following chemical components in percentage by mass: 25.3 percent of Ba, the balance of Al and inevitable impurities, the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-boron alloy comprises the following chemical components in percentage by mass: 10.1 percent of B, the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(3) blowing and refining the aluminum-silicon alloy liquid for 20 minutes by using argon with the purity of 99.9 percent and an aluminum alloy refining agent accounting for 0.5 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, and standing for 10 minutes after slagging off, wherein the aluminum alloy refining agent comprises the following components in percentage by mass: c₂Cl₆ 45.3%，K₃AlF₆ 14.1%，CaCO₃ 9.5%，K₂SO₄ 15.9%，MgSO₄4.1%，KF 2.3%，NaF 5.6%，CaCl₂ 3.2%；

(5) heating cast aluminum-silicon alloy at 495 ℃ for 1.5 hours, then quenching for solid solution treatment, wherein the transfer time of the cast aluminum-silicon alloy is 3 seconds, and the water temperature of the quenching is 30 ℃;

(6) heating the cast aluminum-silicon alloy after the solution treatment at 160 ℃ for 2 hours, then cooling to 150 ℃, continuing to heat for 2 hours for aging treatment, and cooling along with the furnace to obtain the high-strength wear-resistant cast aluminum-silicon alloy.

Comparative example 1

A method for regenerating waste aluminum of cast aluminum-silicon alloy comprises the following steps:

(2) adding an aluminum-barium alloy accounting for 0.1 percent of the total weight of the raw materials and an aluminum-boron alloy accounting for 0.2 percent of the total weight of the raw materials into the aluminum-silicon alloy liquid for refining and modification treatment; wherein the aluminum-nickel-carbon alloy comprises the following chemical components in percentage by mass: 4.99 percent of Ni, 1.02 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-barium alloy comprises the following chemical components in percentage by mass: ba 24.98%, the balance being Al and inevitable impurities, the content of single impurity is less than or equal to 0.05%, the total amount is less than or equal to 0.15%; the aluminum-boron alloy comprises the following chemical components in percentage by mass: 10.12 percent of B, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(3) blowing and refining the aluminum-silicon alloy liquid for 30 minutes by using argon with the purity of 99.9 percent and aluminum alloy refining agent accounting for 0.3 percent of the total weight of the raw materials to carry out degassing and impurity removal treatmentAnd standing for 10 minutes after slagging off, wherein the aluminum alloy refining agent comprises the following components in percentage by mass: c₂Cl₆ 45.3%，K₃AlF₆ 14.1%，CaCO₃ 9.5%，K₂SO₄ 15.9%，MgSO₄4.1%，KF 2.3%，NaF 5.6%，CaCl₂ 3.2%；

(6) heating the cast aluminum-silicon alloy after the solution treatment at 165 ℃ for 1.5 hours, then cooling to 145 ℃, continuing to heat for 3 hours for aging treatment, and cooling along with the furnace to obtain the cast aluminum-silicon alloy.

Comparative example 2

(2) adding an aluminum-nickel-carbon alloy which accounts for 0.4 percent of the total weight of the raw materials into the aluminum-silicon alloy liquid for refining and modification treatment; wherein the aluminum-nickel-carbon alloy comprises the following chemical components in percentage by mass: 5.2 percent of Ni, 1.2 percent of C, and the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-barium alloy comprises the following chemical components in percentage by mass: 25.5 percent of Ba, the balance of Al and inevitable impurities, the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent; the aluminum-boron alloy comprises the following chemical components in percentage by mass: 9.5 percent of B, the balance of Al and inevitable impurities, wherein the content of single impurity is less than or equal to 0.05 percent, and the total amount is less than or equal to 0.15 percent;

(6) heating the cast aluminum-silicon alloy after the solution treatment at 170 ℃ for 1 hour, then cooling to 150 ℃, continuing to heat for 2.5 hours for aging treatment, and cooling along with the furnace to obtain the cast aluminum-silicon alloy.

Comparative example 3

(3) blowing and refining the aluminum-silicon alloy liquid for 20 minutes by using argon with the purity of 99.9 percent and a commercially available aluminum alloy refining agent accounting for 0.5 percent of the total weight of the raw materials to carry out degassing and impurity removal treatment, and standing for 15 minutes after slagging off;

(6) heating the cast aluminum-silicon alloy after the solution treatment at 160 ℃ for 2 hours, then cooling to 140 ℃, continuing to heat for 2 hours for aging treatment, and cooling along with the furnace to obtain the cast aluminum-silicon alloy.

Verification example 1

Samples were taken from the cast aluminum-silicon alloys prepared in examples 1 to 6 and comparative examples 1 to 3, and chemical composition analysis was performed on an ARL-4600 type photoelectric direct-reading spectrometer, the analysis results being shown in Table 1.

Table 1 examples and comparative examples chemical composition (mass%,%) of cast aluminum-silicon alloy

	Si	Cu	Mg	Ti	Fe	Cr	Ba	Ni	C	B
											Example 1	12.80	2.00	0.42	0.34	0.42	0.042	0.025	0.010	0.002	0.020
Example 2	12.54	1.98	0.30	0.22	0.36	0.045	0.051	0.021	0.005	0.010
											Example 3	14.30	1.42	0.36	0.26	0.55	0.024	0.049	0.019	0.005	0.010
Example 4	13.28	1.80	0.44	0.36	0.48	0.025	0.048	0.015	0.003	0.015
											Example 5	14.48	2.06	0.40	0.26	0.58	0.012	0.038	0.010	0.002	0.021
Example 6	13.58	2.44	0.66	0.52	0.59	0.045	0.025	0.010	0.002	0.010
											Comparative example 1	12.80	2.00	0.42	0.34	0.42	0.042	0.025	-	-	0.020
Comparative example 2	12.54	1.98	0.30	0.22	0.36	0.045	-	0.021	0.005	-
											Comparative example 3	14.30	1.42	0.36	0.26	0.55	0.024	0.049	0.019	0.005	0.010

Verification example 2

Samples were taken from the cast aluminium-silicon alloys of example 1, comparative example 1 and comparative example 2, and after grinding, polishing and etching the samples, they were examined on a LEIK-DMI3000M type optical microscope for microstructure, fig. 1 and 2 being the microstructure of the cast aluminium-silicon alloy of example 1 at 100 x magnification and 500 x magnification, respectively. Fig. 3 and 4 show the microstructures of the cast aluminum-silicon alloy of comparative example 1 at a magnification of 100 times and at a magnification of 500 times, respectively. Fig. 5 and 6 show the microstructures of the cast aluminum-silicon alloy of comparative example 2 at a magnification of 100 times and at a magnification of 500 times, respectively.

As can be seen from fig. 1 and 2, in the cast aluminum-silicon alloy of example 1, since the aluminum-nickel-carbon alloy, the aluminum-barium alloy, and the aluminum-boron alloy were added to perform the refining modification treatment, the microstructure of the cast aluminum-silicon alloy did not include coarse dendritic α -Al crystal grains, coarse needle-like eutectic Si phases, and iron-rich phases. As can be seen from fig. 3 and 4, the cast aluminum-silicon alloy of comparative example 1 still has coarse dendritic alpha-Al grains because the aluminum-nickel-carbon alloy is not added for refining. As can be seen from fig. 5 and 6, the cast al-Si alloy of comparative example 2 still had a coarse needle-like shape of eutectic Si phase and iron-rich phase because the al-ba alloy and the al-b alloy were not added for the refining and modification treatment. As can be seen by comparison, the invention can eliminate coarse dendritic alpha-Al grains, coarse needle-like eutectic Si phases and iron-rich phases by adding the aluminum-nickel-carbon alloy, the aluminum-barium alloy and the aluminum-boron alloy for refining and modifying treatment.

Verification example 3

According to the standard GC/T228-. The wear rate of the cast aluminum-silicon alloy was measured on a DNM-350 type frictional wear tester at a load of 8.9N, and the results are shown in table 2.

TABLE 2 tensile mechanical properties and wear rates of cast aluminum-silicon alloys of examples and comparative examples

	Tensile strength/MPa	Elongation/percent	Wear rate/. times.10^-6g/m
				Example 1	519.5	13.4	0.155
Example 2	531.8	12.9	0.151
				Example 3	542.2	12.4	0.147
Example 4	513.9	13.6	0.163
				Example 5	524.1	12.5	0.161
Example 6	552.8	12.2	0.134
				Comparative example 1	461.8	8.6	0.204
Comparative example 2	426.3	7.5	0.251
				Comparative example 3	472.6	10.4	0.214

As can be seen from Table 2, the cast aluminum-silicon alloy prepared by the embodiment of the invention has the room-temperature tensile strength of more than 510MPa, the elongation of more than 12 percent and the wear rate of less than 0.17 multiplied by 10^-6g/m, high strength, good plasticity and excellent wear resistance. The cast aluminum-silicon alloy of the comparative example 1 is not added with the aluminum-nickel-carbon alloy for refining treatment, the cast aluminum-silicon alloy of the comparative example 2 is not added with the aluminum-barium alloy and the aluminum-boron alloy for modification treatment, and the cast aluminum-silicon alloy of the comparative example 3 is not added with the aluminum alloy refining agent for degassing and impurity removal treatment, so that the strength and the plasticity of the cast aluminum-silicon alloy of the comparative examples 1-3 are obviously lower than those of the cast aluminum-silicon alloy of the examples 1-6, and the wear rate of the cast aluminum-silicon alloy of the comparative examples 1-3 is obviously higher than that of the cast aluminum-silicon alloy of the examples 1-6. As can be seen by comparison, the invention carries out refinement modification treatment and refining degassing impurity removal treatment by adding the aluminum-nickel-carbon alloy, the aluminum-barium alloy and the aluminum-boron alloy,the strength, plasticity and wear resistance of the cast aluminum-silicon alloy can be obviously improved.

The above detailed description section specifically describes the analysis method according to the present invention. It should be noted that the above description is only for the purpose of helping those skilled in the art better understand the method and idea of the present invention, and not for the limitation of the related contents. The present invention may be appropriately adjusted or modified by those skilled in the art without departing from the principle of the present invention, and the adjustment and modification also fall within the scope of the present invention.

Claims

1. A method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum is characterized by comprising the following steps:

2. The method for preparing high-strength wear-resistant cast aluminum-silicon alloy from waste aluminum according to claim 1, wherein the raw material in the step (1) further comprises one or more materials selected from aluminum-copper alloy scrap, aluminum-magnesium alloy scrap, aluminum-titanium alloy scrap and aluminum-iron alloy scrap.

3. The method for preparing the high-strength wear-resistant cast aluminum-silicon alloy by using the waste aluminum according to claim 2, wherein the raw materials comprise the following components in percentage by mass based on the total mass of the raw materials: 75-80% of aluminum-silicon alloy waste, 12-15.1% of aluminum-copper alloy waste, 3-5% of aluminum-magnesium alloy waste, 2-4% of aluminum-titanium alloy waste and 1-3% of aluminum-iron alloy waste.

4. The method for preparing high-strength wear-resistant cast aluminum-silicon alloy from waste aluminum according to claim 1, wherein the heating temperature in step (1) is 760-780 ℃.

5. The method for preparing high-strength wear-resistant cast aluminum-silicon alloy from waste aluminum according to claim 1, wherein the mass percentages of the aluminum-nickel-carbon alloy, the aluminum-barium alloy and the aluminum-boron alloy in the step (2) are respectively 0.2-0.4%, 0.1-0.2% and 0.1-0.2% based on the total mass of the raw materials.

6. The method for preparing high-strength wear-resistant cast aluminum-silicon alloy from waste aluminum according to claim 1, wherein the inert gas in the step (3) is one or more selected from nitrogen and argon.

7. The method for preparing high-strength wear-resistant cast aluminum-silicon alloy from waste aluminum according to claim 1, wherein the aluminum alloy refining agent in the step (3) comprises C₂Cl₆，K₃AlF₆，CaCO₃，K₂SO₄，MgSO₄，KF，NaF，CaCl₂。

8. The method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum according to claim 1, wherein the aluminum-silicon alloy liquid after degassing and impurity removal treatment in the step (4) is cast into the aluminum-silicon alloy by using a metal mold under the conditions of 690 and 710 ℃.

9. The method for preparing high-strength wear-resistant cast aluminum-silicon alloy by using waste aluminum as claimed in claim 1, wherein the heating temperature in the step (5) is 495-505 ℃ and the heating time is 1-2 hours.

10. The high-strength wear-resistant cast aluminum-silicon alloy prepared by the method for preparing the high-strength wear-resistant cast aluminum-silicon alloy from the scrap aluminum according to any one of claims 1 to 9.