Silicon micro-alloyed zinc-aluminum-magnesium ternary alloy ingot and preparation method thereof

Abstract

The application discloses a silicon micro-alloyed zinc-aluminum-magnesium ternary alloy ingot and a preparation method thereof, relates to the technical field of zinc-aluminum-magnesium alloy ingot preparation, and comprises the following steps: adding pure aluminum ingots and silicon blocks into a crucible, melting and removing slag, adding aluminum foil coated aluminum-cesium rare earth alloy, continuously melting and removing slag, pouring into a metal mold, cooling, and obtaining a rare earth doped aluminum-silicon alloy; adding nickel sulfate hexahydrate, sodium hypophosphite monohydrate, sodium fluoride, lactic acid and lead acetate trihydrate into deionized water, stirring and uniformly mixing, adjusting the pH to be acidic, ultrasonic dispersion, then adding activated silicon carbide, heating treatment, centrifugal washing and drying, and obtaining a chemical nickel plating silicon carbide; preheating the crucible, adding part of pure zinc ingots, heating and melting, sequentially adding the rare earth doped aluminum-silicon alloy and an aluminum-magnesium alloy, adding the chemical nickel plating silicon carbide after heating and melting, adding the remaining pure zinc ingots, cooling and stirring, refining, degassing and slag removal, and obtaining the zinc-aluminum-magnesium ternary alloy ingot.

Description

Technical Field

[0001] This invention relates to the field of zinc-aluminum-magnesium alloy ingot preparation technology, specifically to a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot and its preparation method. Background Technology

[0002] With the global energy transition and green, low-carbon initiatives, photovoltaic (PV) power generation is gradually becoming a major clean energy source. PV mounting systems are the fundamental structure of PV power generation, and steel is a crucial material in traditional PV mounting systems. Zinc plating is used to achieve the corrosion resistance requirements of PV mounting systems. However, traditional galvanized steel corrosion protection suffers from problems such as insufficient bonding strength between the steel and the zinc coating, easy peeling, and easy damage to the zinc coating during processing and installation. Zinc-aluminum-magnesium alloys, due to their strong corrosion resistance and ultra-long service life, have become a popular material for new PV mounting systems. However, zinc-aluminum-magnesium alloy PV mounting systems have insufficient mechanical strength, are prone to shrinkage cavities during manufacturing, and have difficulty balancing corrosion resistance and mechanical properties, posing a risk of stress corrosion cracking.

[0003] In summary, to solve the above problems, it is of great significance to prepare a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot and its preparation method, so as to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot includes the following steps: S1: Add pure aluminum ingots and silicon blocks to a crucible, melt and remove slag, add aluminum foil-coated aluminum-cerium rare earth alloy, continue to melt and remove slag, pour into a metal mold, cool, and obtain rare earth-doped aluminum-silicon alloy. S2: Add nickel sulfate hexahydrate, sodium hypophosphite monohydrate, sodium fluoride, lactic acid and lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to acidic, disperse by ultrasonication, then add activated silicon carbide, heat treatment, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide. S3: Preheat the crucible to 150-250℃, add some pure zinc ingots, heat and melt, then add rare earth doped aluminum-silicon alloy and aluminum-magnesium alloy in sequence, heat and melt, then add chemically plated nickel-silicon carbide, add pure zinc ingots to make up the balance, cool down and stir, refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingot. The aluminum-cerium rare earth alloy is prepared from pure aluminum ingots and cerium-rich mixed rare earths. The activated silicon carbide was prepared from nickel acetate, sodium borohydride, anhydrous ethanol and silicon carbide.

[0006] Further, in step S1, by mass fraction, the composition is 60-80% pure aluminum ingot, 5-30% silicon block, and 0.5-10% aluminum-cerium rare earth alloy; The preparation method of the aluminum foil-coated aluminum-cerium rare earth alloy is as follows: place the cleaned and decontaminated aluminum-cerium rare earth alloy in the center of an industrial pure aluminum foil with a thickness of 0.1-0.2mm, and completely cover the aluminum-cerium rare earth alloy with aluminum foil on all four sides. Squeeze out the air and repeat twice to obtain the aluminum foil-coated aluminum-cerium rare earth alloy.

[0007] Further, in step S1, the preparation method of the aluminum-cerium rare earth alloy is as follows: pure aluminum ingots are added to a crucible, heated to 720-740℃ until melted, cerium-rich mixed rare earth is added, melted, slag is removed, poured into a metal mold, and cooled to obtain the aluminum-cerium rare earth alloy.

[0008] Furthermore, by mass fraction, the pure aluminum ingot contains 80-90% pure aluminum and 10-20% cerium-rich mixed rare earth elements.

[0009] Furthermore, in step S2, each 1L of deionized water contains 20-30g of nickel sulfate hexahydrate, 20-35g of sodium hypophosphite monohydrate, 0.5-1g of sodium fluoride, 1-2mg of lead acetate trihydrate, 0.5-10g of activated silicon carbide, and 10-30ml of lactic acid.

[0010] Further, in step S2, the preparation method of the activated silicon carbide is as follows: nickel acetate and sodium borohydride are added to anhydrous ethanol and stirred to obtain nickel acetate alcohol solution and sodium borohydride alcohol solution. The silicon carbide is degreased and acid-washed, and then added to nickel acetate alcohol. Sodium hydroxide is added while stirring to adjust the pH to 10-11. Sodium borohydride alcohol solution is added and activated for 1-3 minutes. The silicon carbide is filtered, washed, and vacuum dried to obtain activated silicon carbide.

[0011] Furthermore, the mass ratio of nickel acetate, sodium borohydride, anhydrous ethanol, and silicon carbide is (1-3):(0.1-0.3):100:(5-20).

[0012] Further, in step S3, by mass fraction, the composition is 70-96% pure zinc ingot, 5-8% rare earth-doped aluminum-silicon alloy, 3-5% aluminum-magnesium alloy, and 5-15% electroless nickel-plated silicon carbide.

[0013] Compared with the prior art, the beneficial effects of the present invention are: This invention introduces rare-earth-doped aluminum-silicon alloy into the preparation process of zinc-aluminum-magnesium ternary alloy ingots. First, an aluminum-cerium rare-earth alloy is formed based on cerium-rich mixed rare-earth and high-purity aluminum ingots. This ensures that rare-earth atoms are uniformly dispersed in the aluminum matrix, effectively preventing agglomeration and providing a precursor for subsequent modification treatment of the aluminum matrix. Second, the aluminum-cerium rare-earth alloy is introduced into the aluminum-silicon smelting system, fully utilizing the in-situ modification effect of rare-earth atoms to refine the eutectic silicon structure in the aluminum-silicon alloy, improve the brittleness of the aluminum-silicon phase, increase the uniformity and density of the intermediate alloy structure, reduce smelting defects, and thus improve the corrosion resistance and mechanical strength of the zinc-aluminum-magnesium ternary alloy ingot, enabling it to achieve the service life and strength required for photovoltaic power generation.

[0014] This invention introduces electroless nickel plating on silicon carbide during the preparation of zinc-aluminum-magnesium ternary alloy ingots. First, the silicon carbide surface is activated using a nickel acetate-sodium borohydride-ethanol system, forming uniform nano-nickel active sites in situ on the silicon carbide surface. This provides active sites for subsequent electroless nickel plating and effectively prevents silicon carbide agglomeration. Second, electroless nickel plating is performed on the activated silicon carbide using a lactic acid complexation system, forming a uniform and dense nickel-phosphorus alloy on the activated silicon carbide surface. This improves the compatibility of silicon carbide with the metal matrix, thereby enhancing the stability of the zinc-aluminum-magnesium ternary alloy ingot.

[0015] In summary, this invention refines brittle eutectic silicon by using rare earth-doped aluminum-silicon alloy, and improves its compatibility with the metal matrix by electroless nickel-silicon carbide plating, filling the micro-pores inside the metal matrix and effectively blocking the penetration of corrosive media. The synergistic effect of the two improves the mechanical strength and corrosion resistance of zinc-aluminum-magnesium ternary alloy ingots, thereby improving the mechanical strength and corrosion resistance of zinc-aluminum-magnesium alloy photovoltaic brackets. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the following examples, the aluminum content of the pure aluminum ingot is 99.99%, the zinc content of the pure zinc ingot is 99.99%, and the magnesium content of the aluminum-magnesium alloy is 10%, with the remainder being aluminum.

[0018] Example 1: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot: Step 1: Add 90 parts of pure aluminum ingot to a crucible, heat to 720°C until melted, add 10 parts of cerium-rich mixed rare earth, melt, remove slag, pour into a metal mold, cool, and obtain aluminum-cerium rare earth alloy. S1: Add 80 parts of pure aluminum ingot and 15 parts of silicon block to a crucible, melt at 800℃, remove slag, add 5 parts of aluminum-cerium rare earth alloy covered with aluminum foil, continue melting, remove slag, pour into a metal mold, cool, and obtain rare earth doped aluminum-silicon alloy. Step 2: Add 1 part nickel acetate and 0.1 part sodium borohydride to 100 parts anhydrous ethanol, stir and mix well to obtain nickel acetate alcohol solution and sodium borohydride alcohol solution. Degrease and acid wash 5 parts silicon carbide, then add it to nickel acetate alcohol solution. While stirring, add sodium hydroxide to adjust the pH to 10. Add sodium borohydride alcohol solution, activate for 1 min, filter and wash, and vacuum dry to obtain activated silicon carbide. S2: Add 20 g / L nickel sulfate hexahydrate, 20 g / L sodium hypophosphite monohydrate, 0.5 g / L sodium fluoride, 10 ml / L lactic acid and 1 mg / L lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to 4.5 with sodium bicarbonate, disperse by ultrasonication, then add 0.5 g / L activated silicon carbide, treat at 80℃ for 1 h, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide; S3: Preheat the crucible at 150℃ for 1 hour, add 30 parts of pure zinc ingots, heat to 530℃ until melted, add 5 parts of rare earth doped aluminum-silicon alloy and 3 parts of aluminum-magnesium alloy in sequence, heat to 630℃ for melting, then add 5 parts of electroless nickel-plated silicon carbide and 57 parts of pure zinc ingots, cool and stir, stir and refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingot.

[0019] Example 2: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot: Step 1: Add 85 parts of pure aluminum ingot to a crucible, heat to 720°C until melted, add 15 parts of cerium-rich mixed rare earth, melt, remove slag, pour into a metal mold, cool, and obtain aluminum-cerium rare earth alloy. S1: Add 75 parts of pure aluminum ingot and 18 parts of silicon block to a crucible, melt at 800℃, remove slag, add 7 parts of aluminum-cerium rare earth alloy covered with aluminum foil, continue melting, remove slag, pour into a metal mold, cool, and obtain rare earth doped aluminum-silicon alloy. Step 2: Add 1 part nickel acetate and 0.1 part sodium borohydride to 100 parts anhydrous ethanol, stir and mix well to obtain nickel acetate alcohol solution and sodium borohydride alcohol solution. Degrease and acid wash 5 parts silicon carbide, then add it to nickel acetate alcohol solution. While stirring, add sodium hydroxide to adjust the pH to 10. Add sodium borohydride alcohol solution, activate for 1 min, filter and wash, and vacuum dry to obtain activated silicon carbide. S2: Add 20 g / L nickel sulfate hexahydrate, 20 g / L sodium hypophosphite monohydrate, 0.5 g / L sodium fluoride, 10 ml / L lactic acid and 1 mg / L lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to 4.5 with sodium bicarbonate, disperse by ultrasonication, then add 0.5 g / L activated silicon carbide, treat at 80℃ for 1 h, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide; S3: Preheat the crucible at 150℃ for 1 hour, add 30 parts of pure zinc ingots, heat to 530℃ until melted, add 5 parts of rare earth doped aluminum-silicon alloy and 3 parts of aluminum-magnesium alloy in sequence, heat to 630℃ for melting, then add 5 parts of electroless nickel-plated silicon carbide and 57 parts of pure zinc ingots, cool and stir, stir and refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingot.

[0020] Example 3: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot: Step 1: Add 80 parts of pure aluminum ingot to a crucible, heat to 720°C until melted, add 20 parts of cerium-rich mixed rare earth, melt, remove slag, pour into a metal mold, cool, and obtain aluminum-cerium rare earth alloy. S1: Add 80 parts of pure aluminum ingot and 16 parts of silicon block to a crucible, melt at 800℃, remove slag, add 4 parts of aluminum-cerium rare earth alloy covered with aluminum foil, continue melting, remove slag, pour into a metal mold, cool, and obtain rare earth doped aluminum-silicon alloy. Step 2: Add 1 part nickel acetate and 0.1 part sodium borohydride to 100 parts anhydrous ethanol, stir and mix well to obtain nickel acetate alcohol solution and sodium borohydride alcohol solution. Degrease and acid wash 5 parts silicon carbide, then add it to nickel acetate alcohol solution. While stirring, add sodium hydroxide to adjust the pH to 10. Add sodium borohydride alcohol solution, activate for 1 min, filter and wash, and vacuum dry to obtain activated silicon carbide. S2: Add 20 g / L nickel sulfate hexahydrate, 20 g / L sodium hypophosphite monohydrate, 0.5 g / L sodium fluoride, 10 ml / L lactic acid and 1 mg / L lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to 4.5 with sodium bicarbonate, disperse by ultrasonication, then add 0.5 g / L activated silicon carbide, treat at 80℃ for 1 h, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide; S3: Preheat the crucible at 150℃ for 1 hour, add 30 parts of pure zinc ingots, heat to 530℃ until melted, add 5 parts of rare earth doped aluminum-silicon alloy and 3 parts of aluminum-magnesium alloy in sequence, heat to 630℃ for melting, then add 5 parts of electroless nickel-plated silicon carbide and 57 parts of pure zinc ingots, cool and stir, stir and refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingot.

[0021] Example 4: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot: Step 1: Add 80 parts of pure aluminum ingot to a crucible, heat to 720°C until melted, add 20 parts of cerium-rich mixed rare earth, melt, remove slag, pour into a metal mold, cool, and obtain aluminum-cerium rare earth alloy. S1: Add 80 parts of pure aluminum ingot and 16 parts of silicon block to a crucible, melt at 800℃, remove slag, add 4 parts of aluminum-cerium rare earth alloy covered with aluminum foil, continue melting, remove slag, pour into a metal mold, cool, and obtain rare earth doped aluminum-silicon alloy. Step 2: Add 2 parts nickel acetate and 0.2 parts sodium borohydride to 100 parts anhydrous ethanol, stir and mix well to obtain nickel acetate alcohol solution and sodium borohydride alcohol solution. Degrease and acid wash 10 parts silicon carbide, then add it to nickel acetate alcohol solution. While stirring, add sodium hydroxide to adjust the pH to 10.5. Add sodium borohydride alcohol solution, activate for 1 min, filter and wash, and vacuum dry to obtain activated silicon carbide. S2: Add 25 g / L nickel sulfate hexahydrate, 28 g / L sodium hypophosphite monohydrate, 0.8 g / L sodium fluoride, 20 ml / L lactic acid and 1.5 mg / L lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to 4.5 with sodium bicarbonate, disperse by ultrasonication, then add 5 g / L activated silicon carbide, treat at 80℃ for 1 h, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide; S3: Preheat the crucible at 150℃ for 1 hour, add 31 parts of pure zinc ingots, heat to 530℃ until melted, add 6 parts of rare earth-doped aluminum-silicon alloy and 4 parts of aluminum-magnesium alloy in sequence, heat to 630℃ for melting, then add 10 parts of electroless nickel-plated silicon carbide and 49 parts of pure zinc ingots, cool and stir, stir and refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingots.

[0022] Example 5: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot: Step 1: Add 80 parts of pure aluminum ingot to a crucible, heat to 720°C until melted, add 20 parts of cerium-rich mixed rare earth, melt, remove slag, pour into a metal mold, cool, and obtain aluminum-cerium rare earth alloy. S1: Add 80 parts of pure aluminum ingot and 16 parts of silicon block to a crucible, melt at 800℃, remove slag, add 4 parts of aluminum-cerium rare earth alloy covered with aluminum foil, continue melting, remove slag, pour into a metal mold, cool, and obtain rare earth doped aluminum-silicon alloy. Step 2: Add 3 parts nickel acetate and 0.3 parts sodium borohydride to 100 parts anhydrous ethanol, stir and mix well to obtain nickel acetate alcohol solution and sodium borohydride alcohol solution. Degrease and acid wash 15 parts silicon carbide, then add it to nickel acetate alcohol solution. While stirring, add sodium hydroxide to adjust the pH to 10. Add sodium borohydride alcohol solution, activate for 1 min, filter and wash, and vacuum dry to obtain activated silicon carbide. S2: Add 30 g / L nickel sulfate hexahydrate, 35 g / L sodium hypophosphite monohydrate, 1 g / L sodium fluoride, 30 ml / L lactic acid and 2 mg / L lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to 4.5 with sodium bicarbonate, disperse by ultrasonication, then add 8 g / L activated silicon carbide, treat at 80℃ for 1 h, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide; S3: Preheat the crucible at 150℃ for 1 hour, add 32 parts of pure zinc ingots, heat to 530℃ until melted, add 8 parts of rare earth doped aluminum-silicon alloy and 5 parts of aluminum-magnesium alloy in sequence, heat to 630℃ for melting, then add 15 parts of electroless nickel-plated silicon carbide and 40 parts of pure zinc ingots, cool and stir, stir and refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingots.

[0023] Comparative Example 1: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot: no aluminum-cerium rare earth alloy was introduced into the rare earth-doped aluminum-silicon alloy, and the rest was the same as in Example 5, with the following specific differences: S1: 80 parts of pure aluminum ingot and 20 parts of silicon block were added to a crucible, melted at 800°C, slag was removed, poured into a metal mold, and cooled to obtain a rare earth-doped aluminum-silicon alloy. Step 1: Add 3 parts nickel acetate and 0.3 parts sodium borohydride to 100 parts anhydrous ethanol, stir and mix well to obtain nickel acetate alcohol solution and sodium borohydride alcohol solution. Degrease and acid wash 15 parts silicon carbide, then add it to nickel acetate alcohol solution. While stirring, add sodium hydroxide to adjust the pH to 10. Add sodium borohydride alcohol solution, activate for 1 min, filter and wash, and vacuum dry to obtain activated silicon carbide. S2: Add 30 g / L nickel sulfate hexahydrate, 35 g / L sodium hypophosphite monohydrate, 1 g / L sodium fluoride, 30 ml / L lactic acid and 2 mg / L lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to 4.5 with sodium bicarbonate, disperse by ultrasonication, then add 8 g / L activated silicon carbide, treat at 80℃ for 1 h, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide; S3: Preheat the crucible at 150℃ for 1 hour, add 32 parts of pure zinc ingots, heat to 530℃ until melted, add 8 parts of rare earth doped aluminum-silicon alloy and 5 parts of aluminum-magnesium alloy in sequence, heat to 630℃ for melting, then add 15 parts of electroless nickel-plated silicon carbide and 40 parts of pure zinc ingots, cool and stir, stir and refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingots.

[0024] Comparative Example 2: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot: the silicon carbide was not activated, and the rest was the same as in Example 5. The specific differences are as follows: Step 1: 80 parts of pure aluminum ingot were added to a crucible, heated to 720°C until melted, 20 parts of cerium-rich mixed rare earth were added, melted, slag removed, poured into a metal mold, and cooled to obtain an aluminum-cerium rare earth alloy. S1: Add 80 parts of pure aluminum ingot and 16 parts of silicon block to a crucible, melt at 800℃, remove slag, add 4 parts of aluminum-cerium rare earth alloy covered with aluminum foil, continue melting, remove slag, pour into a metal mold, cool, and obtain rare earth doped aluminum-silicon alloy. S2: Add 30 g / L nickel sulfate hexahydrate, 35 g / L sodium hypophosphite monohydrate, 1 g / L sodium fluoride, 30 ml / L lactic acid and 2 mg / L lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to 4.5 with sodium bicarbonate, disperse by ultrasonication, then add 8 g / L silicon carbide, treat at 80℃ for 1 h, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide; S3: Preheat the crucible at 150℃ for 1 hour, add 32 parts of pure zinc ingots, heat to 530℃ until melted, add 8 parts of rare earth doped aluminum-silicon alloy and 5 parts of aluminum-magnesium alloy in sequence, heat to 630℃ for melting, then add 15 parts of electroless nickel-plated silicon carbide and 40 parts of pure zinc ingots, cool and stir, stir and refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingots.

[0025] Comparative Example 3: A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot: no electroless nickel-plated silicon carbide was introduced into the rare earth-doped aluminum-silicon alloy, and the rest was the same as in Example 5, with the following specific differences: Step 1: 80 parts of pure aluminum ingot were added to a crucible, heated to 720°C until melted, 20 parts of cerium-rich mixed rare earth were added, melted, slag removed, poured into a metal mold, and cooled to obtain an aluminum-cerium rare earth alloy; S1: Add 80 parts of pure aluminum ingot and 16 parts of silicon block to a crucible, melt at 800℃, remove slag, add 4 parts of aluminum-cerium rare earth alloy covered with aluminum foil, continue melting, remove slag, pour into a metal mold, cool, and obtain rare earth doped aluminum-silicon alloy. S2: Preheat the crucible at 150℃ for 1 hour, add 32 parts of pure zinc ingots, heat to 530℃ until melted, add 8 parts of rare earth-doped aluminum-silicon alloy and 5 parts of aluminum-magnesium alloy in sequence, heat to 630℃ for melting, then add 55 parts of pure zinc ingots, cool down and stir, stir and refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingots.

[0026] Performance testing: The zinc-aluminum-magnesium ternary alloy ingot samples prepared in the above examples and comparative examples were subjected to corrosion resistance testing and slow strain rate tensile testing.

[0027] Corrosion resistance test: The surface of the zinc-aluminum-magnesium ternary alloy ingot sample was cleaned and its weight was weighed as W0. Then it was placed in a 3.5% sodium chloride solution and soaked for 72 hours. After that, it was taken out, cleaned and dried, and weighed to obtain the weight W1. The corrosion rate was calculated by the weight loss method.

[0028] Slow strain rate tensile test: At 25℃, zinc-aluminum-magnesium ternary alloy ingot samples were placed in dry air and 3.5% sodium chloride solution, respectively, with a strain rate of 10.-6 s -1 After 72 hours, tensile strength and elongation at break were measured, and stress corrosion index was calculated.

[0029] The experimental results are shown in Table 1 below.

[0030] Table 1 Performance Test Data of Zinc-Aluminum-Magnesium Ternary Alloy Ingots

[0031] Conclusion: The data in the table above show that the corrosion resistance and mechanical properties of zinc-aluminum-magnesium ternary alloy ingots were improved by introducing rare earth-doped aluminum-silicon alloy and electroless nickel-plated silicon carbide.

[0032] In Comparative Example 1, no aluminum-cerium rare earth alloy was introduced into the rare earth-doped aluminum-silicon alloy. Due to the lack of the modification effect of rare earth metals, the eutectic silicon structure in the aluminum-silicon alloy was difficult to refine, which increased the brittleness of the aluminum-silicon phase and thus affected the corrosion resistance and mechanical strength of the zinc-aluminum-magnesium ternary alloy ingot.

[0033] In Comparative Example 2, the silicon carbide was not activated, which increased the risk of silicon carbide agglomeration in the metal matrix and reduced the compatibility between silicon carbide and the metal matrix, thereby affecting the corrosion resistance and mechanical strength of the zinc-aluminum-magnesium ternary alloy ingot.

[0034] In Comparative Example 3, no electroless nickel-silicon carbide plating was introduced into the rare earth-doped aluminum-silicon alloy. Due to the lack of electroless nickel-silicon carbide plating to fill the micro-pore defects inside the metal matrix, the mechanical strength and corrosion resistance of the zinc-aluminum-magnesium ternary alloy ingot were reduced.

[0035] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot, characterized in that: Includes the following steps: S1: Add pure aluminum ingots and silicon blocks to a crucible, melt and remove slag, add aluminum foil-coated aluminum-cerium rare earth alloy, continue to melt and remove slag, pour into a metal mold, cool, and obtain rare earth-doped aluminum-silicon alloy. S2: Add nickel sulfate hexahydrate, sodium hypophosphite monohydrate, sodium fluoride, lactic acid and lead acetate trihydrate to deionized water, stir and mix well, adjust the pH to acidic, disperse by ultrasonication, then add activated silicon carbide, heat treatment, centrifuge, wash and dry to obtain electroless nickel-plated silicon carbide. S3: Preheat the crucible, add some pure zinc ingots, heat and melt, then add rare earth doped aluminum-silicon alloy and aluminum-magnesium alloy in sequence, heat and melt, then add chemically plated nickel-silicon carbide, and pure zinc ingots to make up the balance, cool down and stir, refine, degas and remove slag to obtain zinc-aluminum-magnesium ternary alloy ingots. The aluminum-cerium rare earth alloy is prepared from pure aluminum ingots and cerium-rich mixed rare earths. The activated silicon carbide was prepared from nickel acetate, sodium borohydride, anhydrous ethanol and silicon carbide.

2. The method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot according to claim 1, characterized in that: In step S1, by mass fraction, the composition is 60-80% pure aluminum ingot, 5-30% silicon block, and 0.5-10% aluminum-cerium rare earth alloy.

3. The method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot according to claim 1, characterized in that: In step S1, the preparation method of the aluminum-cerium rare earth alloy is as follows: pure aluminum ingots are added to a crucible, heated to 720-740℃ until melted, cerium-rich mixed rare earth is added, melted, slag is removed, poured into a metal mold, and cooled to obtain the aluminum-cerium rare earth alloy.

4. The method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot according to claim 3, characterized in that: By mass fraction, pure aluminum ingots contain 80-90% pure aluminum and 10-20% cerium-rich mixed rare earth elements.

5. The method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot according to claim 1, characterized in that: In step S2, each 1L of deionized water contains 20-30g of nickel sulfate hexahydrate, 20-35g of sodium hypophosphite monohydrate, 0.5-1g of sodium fluoride, 1-2mg of lead acetate trihydrate, 0.5-10g of activated silicon carbide, and 10-30ml of lactic acid.

6. The method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot according to claim 1, characterized in that: In step S2, the preparation method of the activated silicon carbide is as follows: nickel acetate and sodium borohydride are added to anhydrous ethanol and stirred to obtain nickel acetate alcohol solution and sodium borohydride alcohol solution. The silicon carbide is degreased and acid-washed, and then added to nickel acetate alcohol solution. Sodium hydroxide is added while stirring to adjust the pH to 10-11. Sodium borohydride alcohol solution is added and activated for 1-3 minutes. The silicon carbide is filtered, washed, and vacuum dried to obtain activated silicon carbide.

7. The method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot according to claim 6, characterized in that: The mass ratio of nickel acetate, sodium borohydride, anhydrous ethanol and silicon carbide is (1-3):(0.1-0.3):100:(5-20).

8. The method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot according to claim 1, characterized in that: In step S3, by mass fraction, the composition is 70-96% pure zinc ingot, 5-8% rare earth-doped aluminum-silicon alloy, 3-5% aluminum-magnesium alloy, and 5-15% electroless nickel-plated silicon carbide.

9. The zinc-aluminum-magnesium ternary alloy ingot prepared by the method for preparing a silicon microalloyed zinc-aluminum-magnesium ternary alloy ingot according to claims 1-8.

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