Zinc alloy and preparation method thereof

Abstract

The invention discloses a zinc alloy and a preparation method thereof. The zinc alloy comprises a zinc alloy base material and a polypyrrole cerium oxide composite film, the outer surface of the zinc alloy base material is provided with a microporous structure, and the microporous structure of the zinc alloy base material is coated with a layer of polypyrrole cerium oxide composite film; the zinc alloy base material is prepared from, by mass, 0.05%-0.12% of aluminum, 0.1%-0.3% of manganese, 0.8%-1.5% of copper, 0.01%-0.1% of titanium, 0.01%-0.05% of rhenium and the balance zinc. According to the zinc alloy and the preparation method thereof provided by the invention, the zinc alloy base material is prepared by adopting a process of combining smelting and pouring, equal channel angular pressing, hot rolling and cold rolling, the microporous structure is prepared on the surface of the zinc alloy base material, and the microporous structure is coated with a layer of polypyrrole cerium oxide composite film; and the final zinc alloy has very good mechanical properties and also has good corrosion resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc alloys, and in particular to a zinc alloy and a preparation method thereof. Background Art

[0002] Zinc alloy is an alloy composed of zinc and other elements. Commonly added alloying elements include aluminum, copper, magnesium, cadmium, lead, titanium, etc. Zinc alloy has the advantages of good fluidity, excellent mechanical properties, short production process, low energy consumption, etc., and its application is becoming more and more extensive in the world. Zinc alloy is widely used in packaging, construction, electronics, automobiles and other fields.

[0003] At present, zinc alloy sheets are usually prepared by melting and pouring, extrusion, rolling and other processes. Zinc alloy sheets are widely used in building panels, electronic appliances, communication products, automotive parts and other fields. However, the existing zinc alloy sheets have the following defects: (1) Insufficient mechanical properties, low strength and creep strength; (2) Limited corrosion resistance. Zinc alloy sheets are often set on the surface of products, so there are certain requirements for the corrosion resistance of zinc alloy sheets. The passivation film (such as phosphate) on the surface of zinc alloy sheets is prone to pitting in a humid or salt spray environment. Directly spraying an anti-corrosion film on the surface of zinc alloy sheets also has problems such as insufficient adhesion, lack of environmental protection, and waste generated during the coating process; (3) The processing and molding is difficult. Zinc alloy sheets are prone to cracking during the cold rolling process, and edge cracks or surface wrinkling are prone to occur during the cold rolling process. Summary of the invention

[0004] In view of this, the present invention provides a zinc alloy and a preparation method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A zinc alloy, comprising a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of the polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; The zinc alloy substrate is made of the following raw materials in percentage by mass: 0.05-0.12% aluminum, 0.1-0.3% manganese, 0.8-1.5% copper, 0.01-0.1% titanium, 0.01-0.05% rhenium, and the balance is zinc.

[0006] Furthermore, the thickness of the polypyrrole cerium oxide composite film is 0.5-1 μm.

[0007] A method for preparing a zinc alloy comprises the following steps: S1. Melting and pouring Prepare 99.99% pure zinc ingots, 99.99% pure aluminum ingots, 99.99% pure copper particles, 99.9% pure titanium particles, 99.9% pure manganese powder, and 99.99% pure rhenium powder; polish away impurities and oxides on the surface of each raw material before smelting; According to the proportion, zinc ingot, aluminum ingot, copper granules, titanium granules, manganese powder and rhenium powder are placed in a vacuum induction furnace under argon protection and heated until the raw materials are completely melted and evenly mixed, and the melt is kept at 450-500°C for 60 minutes; A refining agent is added to the melt for refining, the amount of the refining agent added is 0.1-0.3% of the mass of the mixed melt, the refining time is 15-20 minutes, and the refining process is always under an argon atmosphere, the surface scum is removed and degassed to obtain a refined liquid, which is then poured into a preheated graphite mold and an alloy ingot is obtained during air cooling; S2, rapid plastic deformation The alloy ingot is placed in an annealing furnace, kept at 280°C for 6 to 12 hours for homogenization annealing, and then air-cooled to room temperature; The equal-diameter angular extrusion die consists of two channels with the same cross-section and connected; the inner wall of the channel of the extrusion die is coated with molybdenum disulfide for lubrication; the extrusion die and the alloy ingot are preheated respectively, and the alloy ingot is placed in the internal channel of the extrusion die after preheating; under the extrusion of the press, the alloy ingot is pressed in from the vertical channel opening of the extrusion die and pressed out from the horizontal channel opening of the extrusion die to complete the equal-diameter angular extrusion; after each extrusion, the alloy ingot rotates 90° to enter the next pass, and the direction remains unchanged, and then the next pass of equal-diameter angular extrusion is carried out; the extrusion is carried out from 1 pass to 6 passes in sequence; after multiple passes of equal-diameter angular extrusion, the grains are refined to submicron level; Intermediate annealing is performed between multiple equal-diameter angular extrusions. During the intermediate annealing, the alloy is placed in an annealing furnace and kept at 100-250°C for 5-20 minutes. Argon gas protection is introduced during the intermediate annealing. After the six equal-diameter angular extrusions are completed, a final annealing is performed. During the final annealing, the alloy is placed in an annealing furnace and kept at 100-250°C for 1-10 minutes. S3, hot rolling The alloy ingot after rapid plastic deformation is placed in a vacuum resistance furnace, heated to 150-250°C, and kept warm for 60-90 minutes to make the temperature uniform; the heated alloy ingot is then sent to a two-roll reversible hot rolling mill for hot rolling, with a rolling speed of 0.5m / s, a start rolling temperature of 220-250°C, a first pass reduction of 15-20%, and multiple passes of hot rolling are performed in sequence, and the subsequent reduction of each pass is gradually reduced from 15-20% to 10%, and the rolling speed is gradually increased to 1.2m / s, achieving a total deformation of 70-80%, and the thickness of the alloy plate after hot rolling is 2-4mm; argon gas is introduced during the hot rolling process to prevent oxidation; After each hot rolling, spray fine water mist on the surface of the alloy plate to cool the alloy plate to room temperature, and pass argon gas protection during cooling; after each cumulative deformation of 15-20%, the alloy plate is subjected to intermediate annealing. During the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 150-200℃ for 30-45min, and argon gas protection is passed during the intermediate annealing; S4, cold rolling The hot-rolled alloy sheet is placed in a pickling solution for pickling, and then dried after pickling; then the dried alloy sheet is initially annealed, during which the alloy sheet is placed in an annealing furnace and kept at 150-200°C for 90-120 minutes, and argon gas is introduced for protection during the initial annealing; The alloy sheet after initial annealing is sent to a four-roll cold rolling mill for rolling at a rolling speed of 0.3 m / s, with a first pass reduction of 8-10%, followed by multiple passes of hot rolling, with each subsequent pass reduction gradually reduced from 10% to 8%, and a rolling speed gradually increased to 0.8 m / s, achieving a total deformation of 50-70%, and a zinc alloy substrate thickness of 1-2 mm after cold rolling; After each cumulative deformation of 15-20%, the alloy plate is subjected to intermediate annealing. During the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 150±10℃ for 45-60min. Argon gas is passed through during the intermediate annealing for protection. After the cold rolling is completed, the alloy plate is subjected to final annealing. During the final annealing, the alloy plate is kept at 120±10℃ for 45-75min. Argon gas is passed through during the final annealing for protection. During the cold rolling process, finely atomized nano-lubricant is sprayed onto the double-sided surface of the alloy sheet and the rolls of the four-roll cold rolling mill; S5. Surface treatment The cold-rolled zinc alloy substrate is cleaned with alcohol ultrasonically and then dried in a vacuum dryer; a picosecond laser is used to ablate a honeycomb microporous array structure on the surface of the alloy plate by raster scanning in an argon atmosphere; after the microporous array structure is processed by the picosecond laser, the zinc alloy substrate is cleaned again with alcohol ultrasonically and then dried in a vacuum dryer; The ammonium cerium nitrate and citric acid are mixed, and after being dissolved in deionized water, the pH is adjusted to 4-5, and a transparent sol is formed in a water bath at 80-85° C. to prepare a cerium oxide sol; pyrrole monomer is added to the cerium oxide sol, and an ammonium persulfate solution is added dropwise as an oxidant, and the mixture is stirred and polymerized at room temperature for 6-12 hours to make a polypyrrole composite; Finally, the composite sol is coated on the surface of the zinc alloy substrate by dipping or spin coating, and the zinc alloy substrate is placed in a vacuum resistance furnace, heated to 80-120° C. for heat treatment for 1 hour to form a polypyrrole cerium oxide composite film on the surface of the zinc alloy substrate.

[0008] Furthermore, in step S1, the graphite mold is polished to remove surface impurities before use, and then cleaned and dried with deionized water and alcohol in sequence; In step S1, the graphite mold is preheated at 200° C. for 20 min.

[0009] Furthermore, in step S1, the refining agent is hexachloroethane.

[0010] Further, in step S2, the inner angle of the extrusion die is 90° and the outer angle is 20°; In step S2, the extrusion mold is preheated to 120-200°C, and the extrusion mold is kept at 120-200°C for 5-15 minutes; in step S2, the alloy ingot is preheated to 150-250°C.

[0011] Furthermore, in step S4, the pickling solution is sulfuric acid or hydrochloric acid solution, the pickling solution concentration is 5% to 10%, the pickling solution temperature is 40 to 60° C., and the pickling time is 15 to 20 minutes; The nano lubricant is nano graphite emulsion.

[0012] Furthermore, in step S5, the wavelength of the picosecond laser is 10-64 nm, the power is 10-20 W, and the repetition frequency is 50 kHz.

[0013] Furthermore, in step S5, the pore diameter of the micropores is 10-20 μm, and the distance between adjacent micropores is 100-200 μm.

[0014] Compared with the existing technology, the beneficial effects of the present invention are as follows: a zinc alloy provided by the present invention adopts a process combining smelting and casting-equal-diameter angular extrusion-hot rolling-cold rolling to prepare a zinc alloy substrate, and a microporous structure is prepared on the surface of the zinc alloy substrate, and a layer of polypyrrole cerium oxide composite film is coated on the microporous structure, so that the final zinc alloy has good mechanical properties and good corrosion resistance, and can be applied to building panels, electronic appliances, communication products, automotive parts and other fields; the polypyrrole cerium oxide composite film is also more environmentally friendly as an anti-corrosion film layer; the source of pyrrole monomer raw materials is relatively wide and more environmentally friendly, and can be biodegraded under certain conditions; and cerium oxide is a rare earth oxide, which itself has good chemical stability and is environmentally friendly; when the polypyrrole cerium oxide composite film is coated on the surface of the aluminum alloy substrate, no harmful gases and substances such as formaldehyde and benzene will be released, and no pollution will be caused to the surrounding environment. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0016] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0017] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0018] Example 1 A zinc alloy, comprising a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of the polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; The zinc alloy substrate is made of the following raw materials in mass percentage: 0.08% aluminum, 0.2% manganese, 1.2% copper, 0.05% titanium, 0.02% rhenium, and 98.45% zinc. The thickness of the polypyrrole cerium oxide composite film is 0.5 to 1 μm.

[0019] A method for preparing a zinc alloy comprises the following steps: S1. Melting and pouring Prepare zinc ingots with a purity of 99.99%, aluminum ingots with a purity of 99.99%, copper particles with a purity of 99.99%, titanium particles with a purity of 99.9%, manganese powder with a purity of 99.9%, and rhenium powder with a purity of 99.99%; before smelting, polish away impurities and oxides on the surface of each raw material; According to the ratio, zinc ingots, aluminum ingots, copper particles, titanium particles, manganese powder and rhenium powder are placed in a vacuum induction furnace under argon protection and heated until the raw materials are completely melted and evenly mixed. The melt is kept warm at 550°C for 60 minutes, and a refining agent is added to the melt for refining. The refining agent is hexachloroethane. The amount of the refining agent added is 0.3% of the mass of the mixed melt. The refining time is 20 minutes. The refining process is always under argon atmosphere. The surface scum is removed and degassed to obtain a refined liquid, which is then poured into a preheated graphite mold. The pouring speed is controlled during pouring. The pouring is slow at the beginning, fast in the middle, and slow at the end. Before use, a grinder is used to remove surface impurities in the graphite mold, and then it is cleaned and dried with deionized water and alcohol in turn. The graphite mold is preheated at 200°C for 20 minutes. The alloy ingot is obtained in air cooling.

[0020] S2, rapid plastic deformation The alloy ingot was placed in an annealing furnace and kept at 280°C for 12 hours for homogenization annealing, and then air-cooled to room temperature; The equal-diameter angular extrusion die consists of two channels with the same cross-section and connected. The inner angle of the extrusion die is 90° and the outer angle is 20°. Molybdenum disulfide is applied to the inner wall of the channel of the extrusion die for lubrication. The extrusion die and the alloy ingot are preheated separately. The extrusion die is preheated to 150°C, and the extrusion die is kept at 150°C for 10 minutes, while the alloy ingot is preheated to 200°C. After the alloy ingot is preheated, it is placed in the internal channel of the extrusion die. Under the extrusion of the press, the alloy ingot is pressed in from the vertical channel opening of the extrusion die and pressed out from the horizontal channel opening of the extrusion die to complete the equal-diameter angular extrusion. After each extrusion, the alloy ingot rotates 90° to enter the next pass, and the direction remains unchanged, and then the next pass of equal-diameter angular extrusion is performed. The extrusion is performed from 1 pass to 6 passes in sequence. After multiple passes of equal-diameter angular extrusion, the grains are refined to submicron level. Intermediate annealing is performed between multiple equal-diameter angular extrusion passes. During the intermediate annealing, the alloy is placed in an annealing furnace and kept at 250°C for 10 minutes. Argon gas protection is introduced during the intermediate annealing. After the completion of 6 equal-diameter angular extrusion passes, final annealing is performed. During the final annealing, the alloy is placed in an annealing furnace and kept at 200°C for 5 minutes.

[0021] S3, hot rolling The alloy ingot after rapid plastic deformation is placed in a vacuum resistance furnace, heated to 250°C, and kept warm for 60 minutes to make the temperature uniform; the heated alloy ingot is then sent to a two-roll reversible hot rolling mill for hot rolling, with a rolling speed of 0.5m / s, a start rolling temperature of 250°C, a first pass reduction of 20%, and multiple passes of hot rolling are performed in sequence. The subsequent reduction of each pass is gradually reduced from 20% to 10%, and the rolling speed is gradually increased to 1.2m / s, achieving a total deformation of 80%. After hot rolling, the thickness of the alloy plate is 4mm; argon gas is introduced during the hot rolling process to prevent oxidation; After each hot rolling, fine water mist is sprayed onto the surface of the alloy plate to cool the alloy plate to room temperature, and argon gas is passed in for protection during cooling; after each cumulative deformation of the alloy plate of 20%, intermediate annealing is performed, and during the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 200°C for 30 minutes, and argon gas is passed in for protection during the intermediate annealing.

[0022] S4, cold rolling The hot-rolled alloy sheet is placed in a pickling solution for pickling. The pickling solution is sulfuric acid or hydrochloric acid solution. The pickling solution concentration is 8%, the pickling solution temperature is 40°C, and the pickling time is 15 minutes. After pickling, the alloy sheet is dried. Then, the dried alloy sheet is subjected to initial annealing. During the initial annealing, the alloy sheet is placed in an annealing furnace and kept at 200°C for 120 minutes. Argon gas protection is introduced during the initial annealing. The alloy sheet after initial annealing was sent to a four-roll cold rolling mill for rolling at a rolling speed of 0.3 m / s. The first pass reduction was 10%, and multiple passes of hot rolling were performed in sequence. The subsequent pass reduction was gradually reduced from 10% to 8%, and the rolling speed was gradually increased to 0.8 m / s. The total deformation was 50%, and the thickness of the zinc alloy substrate was 2 mm after the cold rolling was completed. After each cumulative deformation of 15%, the alloy plate is subjected to intermediate annealing. During the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 150±10℃ for 60min. Argon gas is passed through during the intermediate annealing for protection. After the cold rolling is completed, the alloy plate is subjected to final annealing. During the final annealing, the alloy plate is kept at 120±10℃ for 60min. Argon gas is passed through during the final annealing for protection. During the cold rolling process, finely atomized nano-lubricant is sprayed onto the double-sided surfaces of the alloy plate and the rollers of the four-roll cold rolling mill; the nano-lubricant is nano-graphite emulsion.

[0023] S5. Surface treatment The cold-rolled zinc alloy substrate is cleaned with alcohol ultrasonically and then dried in a vacuum dryer; a picosecond laser is used to ablate a honeycomb microporous array structure on the surface of the alloy plate by raster scanning in an argon atmosphere; after the microporous array structure is processed by the picosecond laser, the zinc alloy substrate is cleaned again with alcohol ultrasonically and then dried in a vacuum dryer; 4.2 g of ammonium cerium nitrate was mixed with 2 g of citric acid, and 50 mL of deionized water was added to dissolve the mixture, and the pH was adjusted to 4-5. The mixture was placed in a water bath at 80°C to form a transparent sol to prepare a cerium oxide sol. 4.5 g of ammonium persulfate was dissolved in 50 mL of deionized water to prepare an ammonium persulfate solution. 1 mL of pyrrole monomer was added to the cerium oxide sol, and the ammonium persulfate solution was added dropwise as an oxidant. The mixture was polymerized at room temperature with stirring for 12 hours to make polypyrrole composite. Finally, the composite sol is coated on the surface of the zinc alloy substrate by dipping or spin coating, and the zinc alloy substrate is placed in a vacuum resistance furnace, heated to 110° C. for heat treatment for 1 hour to form a polypyrrole cerium oxide composite film on the surface of the zinc alloy substrate.

[0024] Example 2 Compared with Example 1, the difference is: a zinc alloy, including a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; the zinc alloy substrate is made of the following raw materials in mass percentage: 0.05% aluminum, 0.2% manganese, 0.8% copper, 0.05% titanium, 0.02% rhenium, and 98.88% zinc. The thickness of the polypyrrole cerium oxide composite film is 0.5-1 μm.

[0025] The preparation method of the zinc alloy is the same as that of Example 1.

[0026] Example 3 Compared with Example 1, the difference is: a zinc alloy, including a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; the zinc alloy substrate is made of the following raw materials in mass percentage: 0.1% aluminum, 0.3% manganese, 1.0% copper, 0.1% titanium, 0.05% rhenium, and 98.45% zinc. The thickness of the polypyrrole cerium oxide composite film is 0.5-1 μm.

[0027] The preparation method of the zinc alloy is the same as that of Example 1.

[0028] Example 4 Compared with Example 1, the difference is: a zinc alloy, including a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; the zinc alloy substrate is made of the following raw materials in mass percentage: 0.12% aluminum, 0.1% manganese, 1.5% copper, 0.01% titanium, 0.01% rhenium, and 98.26% zinc. The thickness of the polypyrrole cerium oxide composite film is 0.5-1 μm.

[0029] The preparation method of the zinc alloy is the same as that of Example 1.

[0030] Comparative Example 1 A method for preparing pure zinc comprises the following steps: S1. Melting and pouring Prepare zinc ingots with a purity of 99.99%; polish away impurities and oxides on the surface of the zinc ingots before smelting; The zinc ingot is placed in a vacuum induction furnace under argon protection and heated until the raw materials are completely melted and evenly mixed. The melt is kept at 550°C for 60 minutes and then poured into a preheated graphite mold. Before use, the graphite mold is polished to remove surface impurities, and then cleaned and dried with deionized water and alcohol in turn. The graphite mold is preheated at 200°C for 20 minutes; and the zinc ingot is obtained by air cooling.

[0031] S2, hot rolling The zinc ingot after rapid plastic deformation is placed in a vacuum resistance furnace, heated to 250°C, and kept warm for 60 minutes to make the temperature uniform; the heated zinc ingot is then sent to a two-roll reversible hot rolling mill for hot rolling, with a rolling speed of 0.5m / s, a start rolling temperature of 250°C, a first pass reduction of 20%, and multiple passes of hot rolling are performed in sequence, with each subsequent pass reduction gradually reduced from 20% to 10%, and a rolling speed gradually increased to 1.2m / s, achieving a total deformation of 80%, and a zinc plate thickness of 4mm after hot rolling; argon gas is introduced during the hot rolling process to prevent oxidation; After each hot rolling, spray fine water mist onto the surface of the zinc plate to cool the zinc plate to room temperature, and pass argon gas for protection during cooling; after each cumulative deformation of 20%, the zinc plate is subjected to intermediate annealing. During the intermediate annealing, the zinc plate is placed in an annealing furnace and kept at 200°C for 30 minutes, and argon gas is passed for protection during the intermediate annealing.

[0032] Comparative Example 2 A zinc alloy, comprising a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of the polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; The zinc alloy substrate is made of the following raw materials in mass percentage: 0.08% aluminum, 0.2% manganese, 1.2% copper, 0.05% titanium, 0.02% rhenium, and 98.45% zinc. The thickness of the polypyrrole cerium oxide composite film is 0.5 to 1 μm.

[0033] A method for preparing a zinc alloy comprises the following steps: S1. Melting and pouring Prepare zinc ingots with a purity of 99.99%, aluminum ingots with a purity of 99.99%, copper particles with a purity of 99.99%, titanium particles with a purity of 99.9%, manganese powder with a purity of 99.9%, and rhenium powder with a purity of 99.99%; before smelting, polish away impurities and oxides on the surface of each raw material; According to the ratio, zinc ingots, aluminum ingots, copper particles, titanium particles, manganese powder and rhenium powder are placed in a vacuum induction furnace under argon protection and heated until the raw materials are completely melted and evenly mixed. The melt is kept warm at 550°C for 60 minutes, and a refining agent is added to the melt for refining. The refining agent is hexachloroethane. The amount of the refining agent added is 0.3% of the mass of the mixed melt. The refining time is 20 minutes. The refining process is always under argon atmosphere. The surface scum is removed and degassed to obtain a refined liquid, which is then poured into a preheated graphite mold. The pouring speed is controlled during pouring. The pouring is slow at the beginning, fast in the middle, and slow at the end. Before use, a grinder is used to remove surface impurities in the graphite mold, and then it is cleaned and dried with deionized water and alcohol in turn. The graphite mold is preheated at 200°C for 20 minutes. The alloy ingot is obtained in air cooling.

[0034] S2, hot rolling The alloy ingot after rapid plastic deformation is placed in a vacuum resistance furnace, heated to 250°C, and kept warm for 60 minutes to make the temperature uniform; the heated alloy ingot is then sent to a two-roll reversible hot rolling mill for hot rolling, with a rolling speed of 0.5m / s, a start rolling temperature of 250°C, a first pass reduction of 20%, and multiple passes of hot rolling are performed in sequence. The subsequent reduction of each pass is gradually reduced from 20% to 10%, and the rolling speed is gradually increased to 1.2m / s, achieving a total deformation of 80%. After hot rolling, the thickness of the alloy plate is 4mm; argon gas is introduced during the hot rolling process to prevent oxidation; After each hot rolling, fine water mist is sprayed onto the surface of the alloy plate to cool the alloy plate to room temperature, and argon gas is passed in for protection during cooling; after each cumulative deformation of the alloy plate of 20%, intermediate annealing is performed, and during the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 200°C for 30 minutes, and argon gas is passed in for protection during the intermediate annealing.

[0035] Comparative Example 3 A zinc alloy, comprising a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of the polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; The zinc alloy substrate is made of the following raw materials in mass percentage: 0.08% aluminum, 0.2% manganese, 1.2% copper, 0.05% titanium, 0.02% rhenium, and 98.45% zinc. The thickness of the polypyrrole cerium oxide composite film is 0.5 to 1 μm.

[0036] A method for preparing a zinc alloy comprises the following steps: S1. Melting and pouring Prepare zinc ingots with a purity of 99.99%, aluminum ingots with a purity of 99.99%, copper particles with a purity of 99.99%, titanium particles with a purity of 99.9%, manganese powder with a purity of 99.9%, and rhenium powder with a purity of 99.99%; before smelting, polish away impurities and oxides on the surface of each raw material; According to the ratio, zinc ingots, aluminum ingots, copper particles, titanium particles, manganese powder and rhenium powder are placed in a vacuum induction furnace under argon protection and heated until the raw materials are completely melted and evenly mixed. The melt is kept warm at 550°C for 60 minutes, and a refining agent is added to the melt for refining. The refining agent is hexachloroethane. The amount of the refining agent added is 0.3% of the mass of the mixed melt. The refining time is 20 minutes. The refining process is always under argon atmosphere. The surface scum is removed and degassed to obtain a refined liquid, which is then poured into a preheated graphite mold. The pouring speed is controlled during pouring. The pouring is slow at the beginning, fast in the middle, and slow at the end. Before use, a grinder is used to remove surface impurities in the graphite mold, and then it is cleaned and dried with deionized water and alcohol in turn. The graphite mold is preheated at 200°C for 20 minutes. The alloy ingot is obtained in air cooling.

[0037] S2, rapid plastic deformation The alloy ingot was placed in an annealing furnace and kept at 280°C for 12 hours for homogenization annealing, and then air-cooled to room temperature; The equal-diameter angular extrusion die consists of two channels with the same cross-section and connected. The inner angle of the extrusion die is 90° and the outer angle is 20°. Molybdenum disulfide is applied to the inner wall of the channel of the extrusion die for lubrication. The extrusion die and the alloy ingot are preheated separately. The extrusion die is preheated to 150°C, and the extrusion die is kept at 150°C for 10 minutes, while the alloy ingot is preheated to 200°C. After the alloy ingot is preheated, it is placed in the internal channel of the extrusion die. Under the extrusion of the press, the alloy ingot is pressed in from the vertical channel opening of the extrusion die and pressed out from the horizontal channel opening of the extrusion die to complete the equal-diameter angular extrusion. After each extrusion, the alloy ingot rotates 90° to enter the next pass, and the direction remains unchanged, and then the next pass of equal-diameter angular extrusion is performed. The extrusion is performed from 1 pass to 6 passes in sequence. After multiple passes of equal-diameter angular extrusion, the grains are refined to submicron level. Intermediate annealing is performed between multiple equal-diameter angular extrusion passes. During the intermediate annealing, the alloy is placed in an annealing furnace and kept at 250°C for 10 minutes. Argon gas protection is introduced during the intermediate annealing. After the completion of 6 equal-diameter angular extrusion passes, final annealing is performed. During the final annealing, the alloy is placed in an annealing furnace and kept at 200°C for 5 minutes.

[0038] S3, hot rolling The alloy ingot after rapid plastic deformation is placed in a vacuum resistance furnace, heated to 250°C, and kept warm for 60 minutes to make the temperature uniform; the heated alloy ingot is then sent to a two-roll reversible hot rolling mill for hot rolling, with a rolling speed of 0.5m / s, a start rolling temperature of 250°C, a first pass reduction of 20%, and multiple passes of hot rolling are performed in sequence. The subsequent reduction of each pass is gradually reduced from 20% to 10%, and the rolling speed is gradually increased to 1.2m / s, achieving a total deformation of 80%. After hot rolling, the thickness of the alloy plate is 4mm; argon gas is introduced during the hot rolling process to prevent oxidation; After each hot rolling, fine water mist is sprayed onto the surface of the alloy plate to cool the alloy plate to room temperature, and argon gas is passed in for protection during cooling; after each cumulative deformation of the alloy plate of 20%, intermediate annealing is performed, and during the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 200°C for 30 minutes, and argon gas is passed in for protection during the intermediate annealing.

[0039] Comparative Example 4 A zinc alloy, comprising a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of the polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; The zinc alloy substrate is made of the following raw materials in mass percentage: 0.08% aluminum, 0.2% manganese, 1.2% copper, 0.05% titanium, 0.02% rhenium, and 98.45% zinc. The thickness of the polypyrrole cerium oxide composite film is 0.5 to 1 μm.

[0040] A method for preparing a zinc alloy comprises the following steps: S1. Melting and pouring Prepare zinc ingots with a purity of 99.99%, aluminum ingots with a purity of 99.99%, copper particles with a purity of 99.99%, titanium particles with a purity of 99.9%, manganese powder with a purity of 99.9%, and rhenium powder with a purity of 99.99%; before smelting, polish away impurities and oxides on the surface of each raw material; According to the ratio, zinc ingots, aluminum ingots, copper particles, titanium particles, manganese powder and rhenium powder are placed in a vacuum induction furnace under argon protection and heated until the raw materials are completely melted and evenly mixed. The melt is kept warm at 550°C for 60 minutes, and a refining agent is added to the melt for refining. The refining agent is hexachloroethane. The amount of the refining agent added is 0.3% of the mass of the mixed melt. The refining time is 20 minutes. The refining process is always under argon atmosphere. The surface scum is removed and degassed to obtain a refined liquid, which is then poured into a preheated graphite mold. The pouring speed is controlled during pouring. The pouring is slow at the beginning, fast in the middle, and slow at the end. Before use, a grinder is used to remove surface impurities in the graphite mold, and then it is cleaned and dried with deionized water and alcohol in turn. The graphite mold is preheated at 200°C for 20 minutes. The alloy ingot is obtained in air cooling.

[0041] S2, rapid plastic deformation The alloy ingot was placed in an annealing furnace and kept at 280°C for 12 hours for homogenization annealing, and then air-cooled to room temperature; The equal-diameter angular extrusion die consists of two channels with the same cross-section and connected. The inner angle of the extrusion die is 90° and the outer angle is 20°. Molybdenum disulfide is applied to the inner wall of the channel of the extrusion die for lubrication. The extrusion die and the alloy ingot are preheated separately. The extrusion die is preheated to 150°C, and the extrusion die is kept at 150°C for 10 minutes, while the alloy ingot is preheated to 200°C. After the alloy ingot is preheated, it is placed in the internal channel of the extrusion die. Under the extrusion of the press, the alloy ingot is pressed in from the vertical channel opening of the extrusion die and pressed out from the horizontal channel opening of the extrusion die to complete the equal-diameter angular extrusion. After each extrusion, the alloy ingot rotates 90° to enter the next pass, and the direction remains unchanged, and then the next pass of equal-diameter angular extrusion is performed. The extrusion is performed from 1 pass to 6 passes in sequence. After multiple passes of equal-diameter angular extrusion, the grains are refined to submicron level. Intermediate annealing is performed between multiple equal-diameter angular extrusion passes. During the intermediate annealing, the alloy is placed in an annealing furnace and kept at 250°C for 10 minutes. Argon gas protection is introduced during the intermediate annealing. After the completion of 6 equal-diameter angular extrusion passes, final annealing is performed. During the final annealing, the alloy is placed in an annealing furnace and kept at 200°C for 5 minutes.

[0042] S3, cold rolling The hot-rolled alloy sheet is placed in a pickling solution for pickling. The pickling solution is sulfuric acid or hydrochloric acid solution. The pickling solution concentration is 8%, the pickling solution temperature is 40°C, and the pickling time is 15 minutes. After pickling, the alloy sheet is dried. Then, the dried alloy sheet is subjected to initial annealing. During the initial annealing, the alloy sheet is placed in an annealing furnace and kept at 200°C for 120 minutes. Argon gas protection is introduced during the initial annealing. The alloy sheet after initial annealing was sent to a four-roll cold rolling mill for rolling at a rolling speed of 0.3 m / s. The first pass reduction was 10%, and multiple passes of hot rolling were performed in sequence. The subsequent pass reduction was gradually reduced from 10% to 8%, and the rolling speed was gradually increased to 0.8 m / s. The total deformation was 50%, and the thickness of the zinc alloy substrate was 2 mm after the cold rolling was completed. After each cumulative deformation of 15%, the alloy plate is subjected to intermediate annealing. During the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 150±10℃ for 60min. Argon gas is passed through during the intermediate annealing for protection. After the cold rolling is completed, the alloy plate is subjected to final annealing. During the final annealing, the alloy plate is kept at 120±10℃ for 60min. Argon gas is passed through during the final annealing for protection. During the cold rolling process, finely atomized nano-lubricant is sprayed onto the double-sided surfaces of the alloy plate and the rollers of the four-roll cold rolling mill; the nano-lubricant is nano-graphite emulsion.

[0043] Comparative Example 5 A zinc alloy, comprising a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of the polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; The zinc alloy substrate is made of the following raw materials in mass percentage: 0.08% aluminum, 0.2% manganese, 1.2% copper, 0.05% titanium, 0.02% rhenium, and 98.45% zinc. The thickness of the polypyrrole cerium oxide composite film is 0.5 to 1 μm.

[0044] A method for preparing a zinc alloy comprises the following steps: S1. Melting and pouring Prepare zinc ingots with a purity of 99.99%, aluminum ingots with a purity of 99.99%, copper particles with a purity of 99.99%, titanium particles with a purity of 99.9%, manganese powder with a purity of 99.9%, and rhenium powder with a purity of 99.99%; before smelting, polish away impurities and oxides on the surface of each raw material; According to the ratio, zinc ingots, aluminum ingots, copper particles, titanium particles, manganese powder and rhenium powder are placed in a vacuum induction furnace under argon protection and heated until the raw materials are completely melted and evenly mixed. The melt is kept warm at 550°C for 60 minutes, and a refining agent is added to the melt for refining. The refining agent is hexachloroethane. The amount of the refining agent added is 0.3% of the mass of the mixed melt. The refining time is 20 minutes. The refining process is always under argon atmosphere. The surface scum is removed and degassed to obtain a refined liquid, which is then poured into a preheated graphite mold. The pouring speed is controlled during pouring. The pouring is slow at the beginning, fast in the middle, and slow at the end. Before use, a grinder is used to remove surface impurities in the graphite mold, and then it is cleaned and dried with deionized water and alcohol in turn. The graphite mold is preheated at 200°C for 20 minutes. The alloy ingot is obtained in air cooling.

[0045] S2, rapid plastic deformation The alloy ingot was placed in an annealing furnace and kept at 280°C for 12 hours for homogenization annealing, and then air-cooled to room temperature; The equal-diameter angular extrusion die consists of two channels with the same cross-section and connected. The inner angle of the extrusion die is 90° and the outer angle is 20°. Molybdenum disulfide is applied to the inner wall of the channel of the extrusion die for lubrication. The extrusion die and the alloy ingot are preheated separately. The extrusion die is preheated to 150°C, and the extrusion die is kept at 150°C for 10 minutes, while the alloy ingot is preheated to 200°C. After the alloy ingot is preheated, it is placed in the internal channel of the extrusion die. Under the extrusion of the press, the alloy ingot is pressed in from the vertical channel opening of the extrusion die and pressed out from the horizontal channel opening of the extrusion die to complete the equal-diameter angular extrusion. After each extrusion, the alloy ingot rotates 90° to enter the next pass, and the direction remains unchanged, and then the next pass of equal-diameter angular extrusion is performed. The extrusion is performed from 1 pass to 6 passes in sequence. After multiple passes of equal-diameter angular extrusion, the grains are refined to submicron level. Intermediate annealing is performed between multiple equal-diameter angular extrusion passes. During the intermediate annealing, the alloy is placed in an annealing furnace and kept at 250°C for 10 minutes. Argon gas protection is introduced during the intermediate annealing. After the completion of 6 equal-diameter angular extrusion passes, final annealing is performed. During the final annealing, the alloy is placed in an annealing furnace and kept at 200°C for 5 minutes.

[0046] S3, hot rolling The alloy ingot after rapid plastic deformation is placed in a vacuum resistance furnace, heated to 250°C, and kept warm for 60 minutes to make the temperature uniform; the heated alloy ingot is then sent to a two-roll reversible hot rolling mill for hot rolling, with a rolling speed of 0.5m / s, a start rolling temperature of 250°C, a first pass reduction of 20%, and multiple passes of hot rolling are performed in sequence. The subsequent reduction of each pass is gradually reduced from 20% to 10%, and the rolling speed is gradually increased to 1.2m / s, achieving a total deformation of 80%. After hot rolling, the thickness of the alloy plate is 4mm; argon gas is introduced during the hot rolling process to prevent oxidation; After each hot rolling, fine water mist is sprayed onto the surface of the alloy plate to cool the alloy plate to room temperature, and argon gas is passed in for protection during cooling; after each cumulative deformation of the alloy plate of 20%, intermediate annealing is performed, and during the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 200°C for 30 minutes, and argon gas is passed in for protection during the intermediate annealing.

[0047] S4, cold rolling The hot-rolled alloy sheet is placed in a pickling solution for pickling. The pickling solution is sulfuric acid or hydrochloric acid solution. The pickling solution concentration is 8%, the pickling solution temperature is 40°C, and the pickling time is 15 minutes. After pickling, the alloy sheet is dried. Then, the dried alloy sheet is subjected to initial annealing. During the initial annealing, the alloy sheet is placed in an annealing furnace and kept at 200°C for 120 minutes. Argon gas protection is introduced during the initial annealing. The alloy sheet after initial annealing was sent to a four-roll cold rolling mill for rolling at a rolling speed of 0.3 m / s. The first pass reduction was 10%, and multiple passes of hot rolling were performed in sequence. The subsequent pass reduction was gradually reduced from 10% to 8%, and the rolling speed was gradually increased to 0.8 m / s. The total deformation was 50%, and the thickness of the zinc alloy substrate was 2 mm after the cold rolling was completed. After each cumulative deformation of 15%, the alloy plate is subjected to intermediate annealing. During the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 150±10℃ for 60min. Argon gas is passed through during the intermediate annealing for protection. After the cold rolling is completed, the alloy plate is subjected to final annealing. During the final annealing, the alloy plate is kept at 120±10℃ for 60min. Argon gas is passed through during the final annealing for protection. During the cold rolling process, finely atomized nano-lubricant is sprayed onto the double-sided surfaces of the alloy plate and the rollers of the four-roll cold rolling mill; the nano-lubricant is nano-graphite emulsion.

[0048] According to GB / T 228.1-2010 "Tensile Test of Metallic Materials Part 1: Room Temperature Test Method", the tensile strength, yield strength and elongation of the samples were measured at room temperature using a universal tensile testing machine; the zinc alloy samples prepared in Examples 1-4 were all cut by wire cutting, the zinc alloy samples prepared in Comparative Examples 2-5 were all cut by wire cutting, and the pure zinc sample prepared in Comparative Example 1 was cut by wire cutting. All samples were polished with sandpaper to remove the oxide scale and processing defects on the surface of the samples. Three groups of parallel samples were taken from the zinc alloy samples in Examples 1-4, three groups of parallel samples were taken from the zinc alloy samples in Comparative Examples 2-5, and three groups of parallel samples were taken from the pure zinc sample in Comparative Example 1 to ensure the accuracy of the mechanical properties data. The test results are shown in Table 1; According to GB / T 231.1-2009 "Brinell hardness test for metallic materials Part 1: Test method", the Vickers hardness of the sample was measured at room temperature using a Vickers hardness tester; the zinc alloy samples prepared in Examples 1-4 were all cut by wire cutting, the zinc alloy samples prepared in Comparative Examples 2-5 were all cut by wire cutting, and the pure zinc sample prepared in Comparative Example 1 was cut by wire cutting. All samples were polished with sandpaper to remove the oxide scale and processing defects on the surface of the samples. Three groups of parallel samples were taken from the zinc alloy samples in Examples 1-4, three groups of parallel samples were taken from the zinc alloy samples in Comparative Examples 2-5, and three groups of parallel samples were taken from the pure zinc sample in Comparative Example 1 to ensure the accuracy of the mechanical properties data. The test results are shown in Table 1; The zinc alloy sample prepared in Example 1 and the zinc alloy sample prepared in Comparative Example 5 were placed in 3.5% NaCl solution for electrochemical corrosion test. The electrochemical test was carried out on an electrochemical workstation, using a three-electrode system. The zinc alloy samples prepared in Examples 1-4, the pure zinc sample prepared in Comparative Example 1, and the zinc alloy samples prepared in Comparative Examples 2-5 were working electrodes, respectively. A platinum sheet electrode was used as an auxiliary electrode, a saturated calomel electrode was used as a reference electrode, the electrolytic solution was a NaCl solution with a mass fraction of 3.5%, the sample temperature was controlled to be room temperature, and the Tafel curve of each aluminum alloy electrode sample was measured; After the open circuit potential is stabilized, the electrochemical impedance spectroscopy test is performed, the scanning range is OCP ± 250mV, the scanning frequency is set to 1mV / s, and the data of the change of current with potential is recorded. All samples are polished with sandpaper to remove the oxide scale and processing defects on the surface of the samples. Three groups of parallel samples are taken from the zinc alloy sample of Example 1, and three groups of parallel samples are taken from the zinc alloy sample of Comparative Example 5 to ensure the accuracy of the corrosion resistance performance data. The test results are shown in Table 2; The zinc alloy sample prepared in Example 1 and the zinc alloy sample prepared in Comparative Example 5 were fixed on a non-metallic bracket in a salt spray test box to avoid contact with metal parts of the box, and 5% sodium chloride solution was used as the spray medium. Continuous spraying was performed under the conditions of a temperature of 35° C. and a humidity of more than 95%. The start time was recorded, and the test was suspended every 24 hours. The surface state was recorded, and the corrosion condition of the surface of each sample could be observed with a magnifying glass or a microscope to observe whether there were rust spots, peeling, etc.; Three groups of parallel samples were taken from the zinc alloy sample of Example 1, and three groups of parallel samples were taken from the zinc alloy sample of Comparative Example 5 to ensure the accuracy of the observation results. It can be seen from the observation that the surface of the zinc alloy sample of Example 1 is slightly pitted, while the surface of the zinc alloy sample of Comparative Example 5 is evenly covered with white rust and partially red rust.

[0049] Table 1 Mechanical properties test results of Examples 1-4 and Comparative Examples 1-5 Table 2 Corrosion resistance test results of Example 1 and Comparative Example 5 It can be seen that the zinc alloys prepared in Examples 1-4 have excellent mechanical properties and good corrosion resistance. Polypyrrole cerium oxide composite film is also more environmentally friendly as an anti-corrosion film layer; the raw material source of pyrrole monomer is relatively wide and environmentally friendly, and it can be biodegraded under certain conditions; and cerium oxide is a rare earth oxide, which has good chemical stability and is environmentally friendly; when the polypyrrole cerium oxide composite film is coated on the surface of the aluminum alloy substrate, it will not release harmful gases and substances such as formaldehyde and benzene, and will not cause pollution to the surrounding environment; During the equal-channel angular extrusion process of Examples 1-4: the zinc alloy ingot is subjected to shear force when passing through the inflection point of the channel, undergoes strong shear deformation, and obtains an ideal fine grain structure; the size and shape of the zinc alloy ingot before and after extrusion remain almost unchanged, and it can be extruded multiple times, and the strain is accumulated and superimposed, thereby obtaining a larger total strain, achieving the effect of grain refinement, and achieving strong plastic deformation.

[0050] In the hot rolling-cold rolling-drawing process of Examples 1-4: hot rolling provides basic grain refinement and forming capabilities, because heating puts the zinc alloy in a high temperature state, the atomic activity is enhanced, the plasticity of the material is improved, and the deformation resistance is reduced, making the alloy easier to plastic process. The rolling deformation at high temperature can break and refine the coarse grains in the cast structure, promote the full dissolution and uniform distribution of the second phase particles in the alloy, improve the microstructure of the alloy, and improve the comprehensive performance of the alloy. The zinc alloy ingot can be quickly processed into a plate with a certain thickness, width and length through hot rolling, providing a suitable blank for subsequent cold rolling and other processes; Cold rolling is a rolling process carried out at room temperature or lower temperature. It can further process the hot-rolled zinc alloy into plates with high dimensional accuracy and high surface flatness. During the cold rolling process, the zinc alloy undergoes cold deformation, the dislocation density increases significantly, and work hardening occurs, thereby significantly improving the strength, hardness and other mechanical properties of the alloy. Cold rolling can make the surface of the zinc alloy smoother and brighter, eliminate surface oxide scales, pitting and other defects that may be produced during hot rolling, improve the surface quality of the alloy, and enhance its corrosion resistance and appearance quality. Cold rolling is combined with multiple annealing to prevent brittle fracture. The microporous structure on the surface of the aluminum alloy substrate and the polypyrrole cerium oxide composite film coated on the microporous structure greatly improve the overall corrosion resistance of the zinc alloy and meet the application requirements of severe corrosion environments. The zinc alloys prepared in Examples 1-4 are superior to the zinc alloys prepared in Comparative Examples 2-5 in terms of strength and corrosion rate.

[0051] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A zinc alloy, characterized in that: It comprises a zinc alloy substrate and a polypyrrole cerium oxide composite film; the outer surface of the zinc alloy substrate has a microporous structure, and a layer of the polypyrrole cerium oxide composite film is coated on the microporous structure of the zinc alloy substrate; The zinc alloy substrate is made of the following raw materials in percentage by mass: 0.05-0.12% aluminum, 0.1-0.3% manganese, 0.8-1.5% copper, 0.01-0.1% titanium, 0.01-0.05% rhenium, and the balance is zinc.

2. A zinc alloy according to claim 1, characterized in that: The thickness of the polypyrrole cerium oxide composite film is 0.5-1 μm.

3. A method for preparing a zinc alloy as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: S1. Melting and pouring Prepare 99.99% pure zinc ingots, 99.99% pure aluminum ingots, 99.99% pure copper particles, 99.9% pure titanium particles, 99.9% pure manganese powder, and 99.99% pure rhenium powder; polish away impurities and oxides on the surface of each raw material before smelting; According to the proportion, zinc ingot, aluminum ingot, copper granules, titanium granules, manganese powder and rhenium powder are placed in a vacuum induction furnace under argon protection and heated until the raw materials are completely melted and evenly mixed, and the melt is kept at 450-500°C for 60 minutes; A refining agent is added to the melt for refining, the amount of the refining agent added is 0.1-0.3% of the mass of the mixed melt, the refining time is 15-20 minutes, and the refining process is always under an argon atmosphere, the surface scum is removed and degassed to obtain a refined liquid, which is then poured into a preheated graphite mold and an alloy ingot is obtained during air cooling; S2, rapid plastic deformation The alloy ingot is placed in an annealing furnace, kept at 280°C for 6 to 12 hours for homogenization annealing, and then air-cooled to room temperature; The equal-diameter angular extrusion die is composed of two channels with the same cross-section and connected; the inner wall of the channel of the extrusion die is coated with molybdenum disulfide for lubrication; the extrusion die and the alloy ingot are preheated respectively, and the alloy ingot is placed in the inner channel of the extrusion die after preheating; under the extrusion of the press, the alloy ingot is pressed in from the vertical channel opening of the extrusion die and pressed out from the horizontal channel opening of the extrusion die, completing the equal-diameter angular extrusion; After each extrusion, the alloy ingot is rotated 90° to enter the next pass, and the direction remains unchanged, and then the next equal-diameter angular extrusion is carried out; The extrusion process is repeated from 1 pass to 6 passes. After multiple passes of equal-diameter angular extrusion, the grains are refined to submicron level. Intermediate annealing is performed between multiple equal-diameter angular extrusions. During the intermediate annealing, the alloy is placed in an annealing furnace and kept at 100-250°C for 5-20 minutes. Argon gas protection is introduced during the intermediate annealing. After the six equal-diameter angular extrusions are completed, a final annealing is performed. During the final annealing, the alloy is placed in an annealing furnace and kept at 100-250°C for 1-10 minutes. S3, hot rolling The alloy ingot after rapid plastic deformation is placed in a vacuum resistance furnace, heated to 150-250°C, and kept warm for 60-90 minutes to make the temperature uniform; the heated alloy ingot is then sent to a two-roll reversible hot rolling mill for hot rolling, with a rolling speed of 0.5m / s, a start rolling temperature of 220-250°C, a first pass reduction of 15-20%, and multiple passes of hot rolling are performed in sequence, and the subsequent reduction of each pass is gradually reduced from 15-20% to 10%, and the rolling speed is gradually increased to 1.2m / s, achieving a total deformation of 70-80%, and the thickness of the alloy plate after hot rolling is 2-4mm; argon gas is introduced during the hot rolling process to prevent oxidation; After each hot rolling, spray fine water mist on the surface of the alloy plate to cool the alloy plate to room temperature, and pass argon gas protection during cooling; after each cumulative deformation of 15-20%, the alloy plate is subjected to intermediate annealing. During the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 150-200℃ for 30-45min, and argon gas protection is passed during the intermediate annealing; S4, cold rolling The hot-rolled alloy sheet is placed in a pickling solution for pickling, and then dried after pickling; then the dried alloy sheet is initially annealed, during which the alloy sheet is placed in an annealing furnace and kept at 150-200°C for 90-120 minutes, and argon gas is introduced for protection during the initial annealing; The alloy sheet after initial annealing is sent to a four-roll cold rolling mill for rolling at a rolling speed of 0.3 m / s, with a first pass reduction of 8-10%, followed by multiple passes of hot rolling, with each subsequent pass reduction gradually reduced from 10% to 8%, and a rolling speed gradually increased to 0.8 m / s, achieving a total deformation of 50-70%, and a zinc alloy substrate thickness of 1-2 mm after cold rolling; After each cumulative deformation of 15-20%, the alloy plate is subjected to intermediate annealing. During the intermediate annealing, the alloy plate is placed in an annealing furnace and kept at 150±10℃ for 45-60min. Argon gas is passed through during the intermediate annealing for protection. After the cold rolling is completed, the alloy plate is subjected to final annealing. During the final annealing, the alloy plate is kept at 120±10℃ for 45-75min. Argon gas is passed through during the final annealing for protection. During the cold rolling process, finely atomized nano-lubricant is sprayed onto both surfaces of the alloy sheet and the rolls of the four-roll cold rolling mill; S5. Surface treatment The cold-rolled zinc alloy substrate is cleaned with alcohol ultrasonically and then dried in a vacuum dryer; a picosecond laser is used to ablate a honeycomb microporous array structure on the surface of the alloy plate by raster scanning in an argon atmosphere; after the microporous array structure is processed by the picosecond laser, the zinc alloy substrate is cleaned again with alcohol ultrasonically and then dried in a vacuum dryer; The ammonium cerium nitrate and citric acid are mixed, and after being dissolved in deionized water, the pH is adjusted to 4-5, and a transparent sol is formed in a water bath at 80-85° C. to prepare a cerium oxide sol; pyrrole monomer is added to the cerium oxide sol, and an ammonium persulfate solution is added dropwise as an oxidant, and the mixture is stirred and polymerized at room temperature for 6-12 hours to make a polypyrrole composite; Finally, the composite sol is coated on the surface of the zinc alloy substrate by dipping or spin coating, and the zinc alloy substrate is placed in a vacuum resistance furnace, heated to 80-120° C. for heat treatment for 1 hour to form a polypyrrole cerium oxide composite film on the surface of the zinc alloy substrate.

4. The method for preparing a zinc alloy according to claim 3, characterized in that: In step S1, the graphite mold is polished to remove surface impurities before use, and then cleaned and dried with deionized water and alcohol in sequence; In step S1, the graphite mold is preheated at 200° C. for 20 min.

5. The method for preparing a zinc alloy according to claim 3, characterized in that: In step S1, the refining agent is hexachloroethane.

6. The method for preparing a zinc alloy according to claim 3, characterized in that: In step S2, the inner angle of the extrusion die is 90° and the outer angle is 20°; In step S2, the extrusion mold is preheated to 120-200°C, and the extrusion mold is kept at 120-200°C for 5-15 minutes; in step S2, the alloy ingot is preheated to 150-250°C.

7. The method for preparing a zinc alloy according to claim 3, characterized in that: In step S4, the pickling solution is sulfuric acid or hydrochloric acid solution, the pickling solution concentration is 5% to 10%, the pickling solution temperature is 40 to 60°C, and the pickling time is 15 to 20 minutes; The nano lubricant is nano graphite emulsion.

8. The method for preparing a zinc alloy according to claim 3, characterized in that: In step S5, the wavelength of the picosecond laser is 10-64 nm, the power is 10-20 W, and the repetition frequency is 50 kHz.

9. The method for preparing a zinc alloy according to claim 3, characterized in that: In step S5, the pore diameter of the micropores is 10-20 μm, and the distance between adjacent micropores is 100-200 μm.

Images