Anti-zinc oxide alloy and preparation method thereof

Abstract

The invention discloses an anti-zinc oxide alloy and a preparation method thereof, and relates to the field of zinc alloys. The anti-zinc oxide alloy comprises the following components in percentage by weight: 4.0 to 4.3 percent of Al; 0.75 to 0.85% of Cu; 0.03 to 0.05 percent of Mg; 0.0002% to 0.0005% of a Ti alterant; and the balance of Zn. Wherein the impurity content is that Pb is less than or equal to 0.004%; sn < = 0.001%; cd < = 0.0003%; fe < = 0.003%; ag < = 0.0004%; in < = 0.0005%; mn < = 0.0005%; ni < = 0.0005%; si < = 0.002%; tl < = 0.001%; and Cr < = 0.0005%. The zinc alloy has the advantages of being good in oxidation resistance and excellent in corrosion resistance, and meanwhile has good ductility.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of zinc alloy, in particular to an oxidation-resistant zinc alloy and a preparation method thereof. BACKGROUND

[0002] Zinc alloy has been widely used in hardware, bathroom, decoration, automobile parts and other fields due to its good casting performance, mechanical properties and relatively low cost. However, zinc alloy, especially in the smelting and use process, has a significant disadvantage: easy oxidation.

[0003] In the smelting stage, zinc element has a high vapor pressure and chemical activity, and is extremely easy to react with oxygen in the air at high temperature to generate a large amount of zinc oxide dross. This not only leads to the loss of valuable metal materials, increases the production cost, but also seriously deteriorates the casting fluidity of the alloy due to the inclusion of oxide inclusions in the melt, and causes the castings to produce defects such as poor corrosion resistance. SUMMARY

[0004] In order to improve the problem of easy oxidation and poor corrosion resistance stability of zinc alloy, the present application provides an oxidation-resistant zinc alloy and a preparation method thereof.

[0005] In a first aspect, the present application provides an oxidation-resistant zinc alloy using the following technical solution: An oxidation-resistant zinc alloy, the composition and weight percentage content of the oxidation-resistant zinc alloy are as follows: Al, 4.0-4.3%; Cu, 0.75-0.85%; Mg, 0.03-0.05%; Ti modifier, 0.0002-0.0005%; Zn, the balance; Wherein, the impurity content: Pb≤0.004%; Sn≤0.001%; Cd≤0.0003%; Fe≤0.003%; Ag≤0.0004%; In≤0.0005%; Mn≤0.0005%; Ni≤0.0005%; Si≤0.002%; Tl≤0.001%; Cr≤0.0005%; the above components are derived from pure zinc ingot, pure aluminum ingot, copper wire, pure magnesium ingot and Ti modifier.

[0006] In this application, the main constituent elements of the anti-oxidation zinc alloy are Al, Cu, Mg, and Zn, with Ti acting as a modifier. Al has a much higher affinity for oxygen than Zn, and upon contact with oxygen, it readily oxidizes to form a dense and continuous Al₂O₃ film, which spreads across the melt surface, preventing Zn oxidation and escape. Furthermore, Cu can reduce Zn activity and enter the β-ZnAl phase, forming Cu-rich microregions and preventing oxidation from propagating vertically and forming localized deep pits. The addition of Mg can inhibit intergranular corrosion and refine the eutectic structure, improving the corrosion resistance and ductility of the zinc alloy. Ti can refine grains and inhibit intergranular corrosion, improving the fluidity and ductility of the zinc alloy. The zinc alloy of this application possesses the advantages of good oxidation resistance, excellent corrosion resistance, and good ductility.

[0007] In some specific embodiments, the impurity content is as follows: Pb ≤ 0.003%; Sn ≤ 0.001%; ​​Cd ≤ 0.0003%; Fe, 0.0015-0.003%; Ag, 0.0002-0.0004%; In ≤ 0.0005%; Mn ≤ 0.0005%; Ni ≤ 0.0005%; Si, 0.001-0.002%; Tl, 0.0008-0.0009%; Cr ≤ 0.0005%.

[0008] In some specific embodiments, the zinc in the pure zinc ingot has a weight percentage of ≥99.995%.

[0009] In some specific embodiments, the weight percentage of aluminum in the pure aluminum ingot is ≥99.9%.

[0010] In some specific embodiments, the weight percentage of copper in the copper wire is ≥99.99%.

[0011] In some specific embodiments, the magnesium in the pure magnesium ingot has a magnesium weight percentage of ≥99.95%.

[0012] Secondly, the preparation method of the antioxidant zinc alloy provided in this application adopts the following technical solution: A method for preparing an antioxidant zinc alloy includes the following steps: Raw material preparation: Prepare pure zinc ingots, pure aluminum ingots, copper wire, pure magnesium ingots, and Ti modifier according to their weight percentages; Al-50Cu alloy preparation: Al-50Cu alloy was prepared by taking all copper wires and an equal mass of pure aluminum ingots; Melting: Under inert gas protection, pure zinc ingots (55-65% of the total mass of pure zinc ingots) and the remaining pure aluminum ingots are heated to 600-620℃ and melted uniformly. A covering agent is added during the melting process to obtain melt A. Melt A is heated to 680-700℃, Al-50Cu alloy is added, and melting is continued to be uniform to obtain melt B. Melt B is cooled to 600-620℃, the remaining pure zinc ingots are added, and melting is continued to be uniform to obtain melt C. Melt C is cooled to 420-450℃, a refining agent is added for refining, and then it is allowed to stand for 5-10 minutes to remove surface floating residue. Melt C is kept at 420-450℃, pure magnesium ingots are added, and melting is carried out uniformly. Then Ti modifier is added, and melting is continued to be uniform. The slag is removed to obtain a zinc alloy solution. Casting: The molten zinc alloy is poured into a mold and cooled to 330-350℃ at a rate of 3-5℃ / min, held for 10-12 hours, and then cooled to 280-300℃ at a rate of 0.1-0.2℃ / min to obtain a casting blank; the casting blank is extruded and then annealed at 160-180℃ for 1-2 hours to obtain an anti-oxidation zinc alloy.

[0013] In this application, the above-mentioned method is preferred for preparing the antioxidant zinc alloy. Cu is first prepared as an Al-50Cu alloy and then smelted in this form, which promotes uniform dispersion of Cu in the zinc alloy. The pure zinc ingot is added in two parts, which reduces the oxidation and evaporation losses of Zn and facilitates uniform melting between the metals. Adding a covering agent and a refining agent during the melting process reduces the oxidation losses of Zn, Al, and Mg, and prevents oxide residues in the zinc alloy, thereby improving the oxidation resistance and corrosion resistance of the zinc alloy. A two-step cooling method with a specific cooling rate, plus an annealing operation, further refines the grain structure and improves the tensile strength and elongation of the zinc alloy.

[0014] In some specific embodiments, the preparation of Al-50Cu alloy includes the following steps: Under inert gas protection, pure aluminum ingots are melted uniformly at 600-650℃, copper wire is added, and after uniform melting, the gas and slag are removed, and then cast to obtain Al-50Cu alloy.

[0015] In this application, Cu is added in the form of Al-50Cu alloy, and suitable pure aluminum ingots and pure zinc ingots are reserved for co-melting, which helps to reduce the burn-off rate of zinc alloy.

[0016] In some specific embodiments, the mass of the covering agent is 0.2-0.5% of the weight of the furnace charge.

[0017] In some specific embodiments, the refining agent is present at a mass of 0.1-0.3% of the furnace charge weight.

[0018] In summary, this application includes at least the following beneficial technical effects: (1) In this application, the main constituent elements of the anti-oxidation zinc alloy are Al, Cu, Mg, and Zn, with Ti acting as a modifier. Al has a much higher affinity for oxygen than Zn, and upon contact with oxygen, it readily oxidizes into a dense and continuous Al2O3 film, which spreads across the melt surface, preventing Zn oxidation and escape. Furthermore, Cu can reduce Zn activity and enter the β-ZnAl phase, forming Cu-rich microregions, preventing oxidation from advancing vertically and forming localized deep pits. The addition of Mg can inhibit intergranular corrosion and refine the eutectic structure, improving the corrosion resistance and ductility of the zinc alloy. Ti can refine grains and inhibit intergranular corrosion, improving the fluidity and ductility of the zinc alloy. The zinc alloy of this application has the advantages of good oxidation resistance, excellent corrosion resistance, and good ductility.

[0019] (2) In this application, the above-mentioned method is preferred for preparing the antioxidant zinc alloy. Cu is first prepared as an Al-50Cu alloy and then smelted in this form, which promotes uniform dispersion of Cu in the zinc alloy. The pure zinc ingot is added in two parts, which reduces the oxidation and evaporation losses of Zn and facilitates uniform melting between the metals. Adding a covering agent and a refining agent during the melting process reduces the oxidation losses of Zn, Al, and Mg, prevents oxide residues in the zinc alloy, and improves the oxidation resistance and corrosion resistance of the zinc alloy. A two-step cooling method with a specific cooling rate, plus an annealing operation, further refines the grain structure and improves the tensile strength and elongation of the zinc alloy. Detailed Implementation

[0020] The following detailed experiments further illustrate this application. The covering agent used in this application consists of 40 wt% sodium chloride, 50 wt% potassium chloride, 5 wt% cryolite, and 5 wt% sodium fluoride, while the refining agent consists of 50 wt% cryolite, 25 wt% sodium chloride, 20 wt% potassium chloride, and 5 wt% sodium nitrate. Example

[0021]

Example 1

[0022] S2, Al-50Cu alloy preparation: Take 150kg of copper wire and 150kg of pure aluminum ingot. Under argon protection, melt the pure aluminum ingot at 600℃ until uniform, add copper wire, melt until uniform, remove gas and slag, and then cast to obtain Al-50Cu alloy. S3. Melting: Under argon protection, 4890 kg of Feilong 0# zinc ingot, 6120 kg of Hualian 0# zinc ingot, and 629.5 kg of pure aluminum ingot are heated to 600℃ and melted uniformly. During the melting process, 40 kg of covering agent is added to obtain melt A. Melt A is heated to 700℃, Al-50Cu alloy is added, and melting is continued to be uniform to obtain melt B. Melt B is cooled to 620℃, 6623 kg of Qilin 0# zinc ingot is added, and melting is continued to be uniform to obtain melt C. Melt C is cooled to 420℃, 37 kg of refining agent is added for refining, and then it is allowed to stand for 10 minutes to remove surface floating residue. Melt C is kept at 420℃, pure magnesium ingot is added, and melting is carried out uniformly. Then 4.5 kg of Ti modifier is added, and melting is continued to be uniform. Slag is removed to obtain zinc alloy solution. S4. Casting and molding: The zinc alloy molten liquid is poured into a mold, cooled to 350°C at a rate of 3°C / min, held for 10 hours, and then cooled to 280°C at a rate of 0.1°C / min to obtain a casting blank; the casting blank is extruded and then annealed at 160°C for 2 hours to obtain an anti-oxidation zinc alloy.

[0023]

Example 2

[0024]

Example 3

[0025]

Example 4

[0026]

Example 5

[0027]

Example 6

[0028] Five samples were randomly selected from Examples 1-6 for alloy element composition testing. The average content of zinc alloy elements in each example is recorded in Table 1 below: Table 1. Average content of zinc alloying elements in Examples 1-6 Element Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Al 4.1211 4.0876 4.1826 4.0584 4.0786 4.0826 Cu 0.7986 0.7900 0.8249 0.7974 0.7850 0.7749 Mg 0.0436 0.0432 0.0488 0.0428 0.0426 0.0435 Pb 0.0028 0.0027 0.0032 0.0027 0.0026 0.0027 Sn 0 0 0 0 0 0 Cd 0 0 0 0 0 0 Fe 0.0018 0.0020 0.0026 0.0018 0.0019 0.0019 Ag 0.0003 0.0003 0.0006 0.0003 0.0003 0.0002 In 0 0 0 0 0 0 Mn 0 0 0 0 0 0 Ni 0 0 0 0 0 0 Si 0.0011 0.0012 0.0015 0.0012 0.0011 0.0012 Ti 0.0002 0.0002 0.0003 0.0002 0.0003 0.0002 Tl 0.0008 0.0009 0.0011 0.0009 0.0010 0.0009 Cr 0 0 0 0 0 0 Zn Balance Balance Balance Balance Balance Balance Calculate the average burn-off rate of the zinc alloy in Examples 1-6. Burn-off rate = total weight of zinc alloy / 18575.5 * 100%, and record the results in Table 2 below: Table 2 Burn-off Rate Sample Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Burn-off rate 0.054％ 0.065％ 0.21％ 0.059％ 0.061％ 0.068％ Based on the test data in Examples 1-6 and Table 2, it can be seen that when Cu is added in the form of Al-Cu alloy, adding it in the form of Al-50Cu alloy and controlling the amount of pure aluminum ingot added when pure zinc ingot is melted is beneficial to reducing the evaporation or oxidation of zinc, thereby reducing the overall burn-off rate.

[0029] Five samples were randomly selected from Examples 1-6 for salt spray corrosion resistance testing, referring to the acetic acid salt spray test in GB / T 10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test". The results are recorded in Table 3 below: Table 3 Salt spray corrosion resistance Five samples were randomly selected from Examples 1-6 for tensile strength and elongation tests, and the results are recorded in Table 4 below: Table 4 Mechanical Property Tests Based on the test data in Table 3-4 above, it can be seen that the zinc alloys with low content of each component within the scope of this application have low oxidation impurities and good corrosion resistance. In particular, cooling and adding annealing operations according to the provisions of this application can effectively improve the tensile strength and elongation of the zinc alloys.

[0030] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this specific embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An antioxidant zinc alloy, characterized in that: The composition and weight percentage of the antioxidant zinc alloy are as follows: Al, 4.0-4.3%; Cu, 0.75-0.85%; Mg, 0.03-0.05%; Ti modifier, 0.0002-0.0005%; Zn, balance; The impurity content is as follows: Pb≤0.004%; Sn≤0.001%; ​​Cd≤0.0003%; Fe≤0.003%; Ag≤0.0006%; In≤0.0005%; Mn≤0.0005%; Ni≤0.0005%; Si≤0.002%; Tl≤0.0015%; Cr≤0.0005%. The above components are derived from pure zinc ingots, pure aluminum ingots, copper wire, pure magnesium ingots, and Ti modifier.

2. The antioxidant zinc alloy according to claim 1, characterized in that: Impurity content: Pb≤0.003%; Sn≤0.001%; ​​Cd≤0.0003%; Fe, 0.0015-0.003%; Ag, 0.0002-0.0004%; In≤0.0005%; Mn≤0.0005%; Ni≤0.0005%; Si, 0.001-0.002%; Tl, 0.0008-0.0009%; Cr≤0.0005%.

3. The antioxidant zinc alloy according to claim 1 or 2, characterized in that: The zinc in the pure zinc ingot has a weight percentage of ≥99.995%.

4. An antioxidant zinc alloy according to claim 1 or 2, characterized in that: The weight percentage of aluminum in the pure aluminum ingot is ≥99.9%.

5. An antioxidant zinc alloy according to claim 1 or 2, characterized in that: The copper wire contains ≥99.99% copper by weight.

6. An antioxidant zinc alloy according to claim 1 or 2, characterized in that: The magnesium ingot contains ≥99.95% magnesium by weight.

7. A method for preparing an antioxidant zinc alloy according to any one of claims 1-6, characterized in that, Includes the following steps: Raw material preparation: Prepare pure zinc ingots, pure aluminum ingots, copper wire, pure magnesium ingots, and Ti modifier according to their weight percentages; Al-50Cu alloy preparation: Al-50Cu alloy was prepared by taking all copper wires and an equal mass of pure aluminum ingots; Melting: Under inert gas protection, pure zinc ingots (55-65% of the total mass of pure zinc ingots) and the remaining pure aluminum ingots are heated to 600-620℃ and melted uniformly. A covering agent is added during the melting process to obtain melt A. Melt A is heated to 680-700℃, Al-50Cu alloy is added, and melting is continued to be uniform to obtain melt B. Melt B is cooled to 600-620℃, the remaining pure zinc ingots are added, and melting is continued to be uniform to obtain melt C. Melt C is cooled to 420-450℃, a refining agent is added for refining, and then it is allowed to stand for 5-10 minutes to remove surface floating residue. Melt C is kept at 420-450℃, pure magnesium ingots are added, and melting is carried out uniformly. Then Ti modifier is added, and melting is continued to be uniform. The slag is removed to obtain a zinc alloy solution. Casting: The molten zinc alloy is poured into a mold and cooled to 330-350℃ at a rate of 3-5℃ / min, held for 10-12 hours, and then cooled to 280-300℃ at a rate of 0.1-0.2℃ / min to obtain a casting blank; the casting blank is extruded and then annealed at 160-180℃ for 1-2 hours to obtain an anti-oxidation zinc alloy.

8. The method for preparing an antioxidant zinc alloy according to claim 7, characterized in that: The preparation of Al-50Cu alloy specifically includes the following steps: Under inert gas protection, pure aluminum ingots are melted uniformly at 600-650℃, copper wire is added, and after uniform melting, the gas and slag are removed, and then cast to obtain Al-50Cu alloy.

9. The method for preparing an antioxidant zinc alloy according to claim 7, characterized in that: The mass of the covering agent is 0.2-0.5% of the weight of the furnace charge.

10. The method for preparing an antioxidant zinc alloy according to claim 7, characterized in that: The mass of the refining agent is 0.1-0.3% of the weight of the furnace charge.

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