High-strength zinc alloy material and method for manufacturing the same

Abstract

This invention discloses a high-strength zinc alloy material and its preparation method. The method involves melting pure Zn, adding pure Cu, adding charcoal covering material, heating to 650±3℃, and stirring until the Cu is completely melted. Pure Al is then added, and after slaking, the temperature is raised to 750–790℃. Thin sheets of intermediate alloy are sequentially pressed into the liquid metal, and after slaking, the temperature is lowered to 650±3℃. Pure Mg is added, and after the Mg melts, the mixture is stirred until homogeneous. The mixture is allowed to stand for 5 minutes, then cooled to 500±3℃, slag is removed, and the mixture is poured into a metal mold. When the mold temperature is below 150℃, the mold is opened, the cast Zn alloy is removed, and it is allowed to cool naturally. The cast Zn alloy is then solution-treated at 300–360℃ for 3–9 hours, followed by water cooling to obtain the high-strength zinc alloy material. This invention obtains high-strength zinc alloy materials by selecting the type and content of alloying elements and using a combination of alloying and solution treatment. This method is simple, low-cost, and significantly improves the tensile strength of the resulting zinc alloy material.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical material development technology, and particularly relates to a high-strength zinc alloy material and its preparation method. Background Technology

[0002] Zinc is an important non-ferrous metal, but pure zinc has poor mechanical properties and is mostly used in alloy form. Zinc alloys have advantages such as low melting point, easy forming, and good machinability, and are widely used in automobiles, daily building hardware, electromechanical equipment, and instruments. To improve the performance of zinc alloys, alloying technology is often used, adding one or more alloying elements to pure zinc to prepare zinc alloys. Commonly used additives to strengthen zinc alloys are micro-copper and aluminum, forming binary or multi-element zinc alloys. The strength of zinc alloys is closely related to the type and content of the added alloying elements and the forming method. For example, zinc alloys prepared using deformation forming technology generally have higher strength than cast zinc alloys. Commercial ZA series zinc-aluminum-copper ternary alloys generally have low tensile strength, mainly because the alloy microstructure consists of a lamellar eutectic structure and a coarse dendritic zinc matrix solid solution. These structural characteristics limit the application range of zinc alloys.

[0003] Wang Jianhua et al.'s invention patent "A method for modifying zinc-aluminum alloy" (patent number CN 113416868B) uses the modifier Al-5Ti-B to modify liquid metal, increasing the tensile strength of the cast zinc alloy to 314.5 MPa; Li Xintao et al.'s invention patent "A zinc alloy and its preparation method" (patent number CN 111621672 B) reports a zinc alloy with a chemical composition of 4.5-7.5% Cu, 2-10.5% Al, 0.1-0.8% Mg, 0.05-0.12% Ti, and 0.05-0.1% Zr, which is formed by extrusion casting and then heat treated, achieving a tensile strength of up to 540 MPa.

[0004] In summary, both alloying and hot deformation processing can improve the strength of zinc alloys, with hot deformation processing being particularly effective. However, hot deformation inevitably increases the number of alloy preparation steps, leading to higher costs. Therefore, there is an urgent need to develop high-performance zinc alloys and their efficient, low-cost preparation processes to obtain high-performance zinc alloys with promising applications. Summary of the Invention

[0005] To overcome the shortcomings and deficiencies of the prior art, the present invention aims to provide a high-strength zinc alloy material and its preparation method.

[0006] This invention is achieved through a method for preparing a high-strength zinc alloy material, which includes the following steps:

[0007] (1) Melt pure Zn in a graphite crucible, add pure Cu and charcoal covering, heat to 650±3℃, and after Cu has completely melted, stir and mix evenly, then add pure Al.

[0008] (2) After all the pure Cu and Al have been purified, the temperature is raised to 750-790℃, and the thin-film Al-10B, Al-10V and Al-20Ti master alloys are pressed into the liquid metal.

[0009] (3) After all the added intermediate alloys have been melted and cleared, stir evenly, cool down to 650±3℃, add pure Mg, after Mg melts, stir and mix evenly, let stand for 5±1 minutes, cool down to 500±3℃, remove slag, pour into a metal mold with room temperature, and when the mold temperature is less than 150℃, open the mold and take out the cast Zn alloy, and let it cool naturally.

[0010] (4) The as-cast Zn alloy is solution-treated at 300-360℃ for 3-9 hours and then water-cooled to obtain a high-strength zinc alloy material. In the high-strength zinc alloy material, based on 100 parts by mass of pure Zn, the mass parts of other components in the material are: 4-6 parts by mass of Cu, 6-8 parts by mass of Al, 2-4 parts by mass of Al-10B master alloy, 2-4 parts by mass of Al-10V master alloy, 2-4 parts by mass of Al-20Ti master alloy, and 0.1-0.15 parts by mass of pure Mg.

[0011] Preferably, in the high-strength zinc alloy material, based on 100 parts by mass of pure Zn, the mass parts of each component are as follows: the mass parts of other components in the material are as follows: 4 parts by mass of Cu, 8 parts by mass of Al, 3 parts by mass of Al-10B master alloy, 4 parts by mass of Al-10V master alloy, 2 parts by mass of Al-20Ti master alloy, and 0.1 parts by mass of pure Mg.

[0012] Preferably, in step (4), the as-cast Zn alloy is solution-treated and held at 340℃~360℃ for 3~6 hours.

[0013] Preferably, in step (4), the as-cast Zn alloy is solution-treated and held at 360°C for 6 hours.

[0014] Preferably, in step (2), the intermediate alloy further includes Al-25Sr; wherein, in the high-strength zinc alloy material, the mass part of Al-25Sr intermediate alloy is 1 to 4 parts per 100 parts by mass of pure Zn.

[0015] Preferably, in step (2), the thickness of the Al-10B, Al-10V, Al-20Ti and Al-25Sr master alloys is 2 mm.

[0016] The present invention further discloses a high-strength zinc alloy material prepared by the above method. In this high-strength zinc alloy material, based on 100 parts by mass of pure Zn, the mass parts of other components in the material are as follows: 4-6 parts by mass of Cu, 6-8 parts by mass of Al, 2-4 parts by mass of Al-10B master alloy, 2-4 parts by mass of Al-10V master alloy, 2-4 parts by mass of Al-20Ti master alloy, and 0.1-0.15 parts by mass of pure Mg.

[0017] Preferably, in the high-strength zinc alloy material, based on 100 parts by mass of pure Zn, the mass parts of other components in the material are as follows: 4 parts by mass of Cu, 8 parts by mass of Al, 3 parts by mass of Al-10B master alloy, 4 parts by mass of Al-10V master alloy, 2 parts by mass of Al-20Ti master alloy, and 0.1 parts by mass of pure Mg.

[0018] This invention overcomes the shortcomings of existing technologies and provides a high-strength zinc alloy material, its preparation method, and its applications. Firstly, this invention employs alloying technology, adding alloying elements to pure zinc. On one hand, the alloying elements dissolve into the pure zinc; during the solidification process of the liquid alloy, the alloying elements dissolve into the primary zinc phase, thus strengthening the primary zinc phase through solid solution. On the other hand, the high-temperature phase formed by the alloying elements in the liquid metal hinders the growth of the primary zinc phase or acts as a heterogeneous nucleation core, refining the grain size of the primary zinc phase. Subsequently, a solid solution treatment further increases the solid solubility of the alloying elements within the primary phase. Therefore, through the combined effect of solid solution strengthening and grain refinement, the strength of the zinc alloy can be significantly improved.

[0019] Compared with the shortcomings and deficiencies of the prior art, the present invention has the following beneficial effects: Compared with the high cost and complex hot deformation processing, the present invention obtains high-strength zinc alloy materials by selecting the type and content of alloying elements and using a combination of alloying and solid solution treatment. This method has the characteristics of simple process and low cost, and the tensile strength of the obtained zinc alloy materials is significantly improved. Attached Figure Description

[0020] Figure 1 Metallographic photograph of the as-cast Zn alloy 1 in Example 1;

[0021] Figure 2 The image shows a metallographic photograph of the high-strength zinc alloy material 1 in Example 1.

[0022] Figure 3 The image shows a scanning electron microscope (SEM) image of the tensile fracture surface of the as-cast Zn alloy 1 in Example 1.

[0023] Figure 4 This is a scanning electron microscope image of the tensile fracture surface of the high-strength zinc alloy material 1 in Example 1. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] The high-strength zinc alloy materials used in the embodiments of the present invention are as follows: Zn purity greater than or equal to 99.9%, Al purity greater than or equal to 99.9%, Cu purity greater than or equal to 99.9%, Mg purity greater than or equal to 99.99%, sheet-like Al-20Ti master alloy, sheet-like Al-10B master alloy, sheet-like Al-10V master alloy, and sheet-like Al-25Sr master alloy.

[0026] The aforementioned master alloys are pre-formed products. Al-20Ti indicates that the master alloy contains 80% Al and 20% Ti; Al-10B indicates that the master alloy contains 90% Al and 10% B; Al-10V indicates that the master alloy contains 90% Al and 10% V; and Al-25Sr indicates that the master alloy contains 75% Al and 25% Sr. Master alloys are typically in ingot form. In this embodiment of the invention, because the amount added is small and to facilitate rapid melting, it is preferable to pre-process them into thin sheets with a thickness of approximately 2 mm before adding them to the molten alloy.

[0027] Example 1

[0028] Based on 100 parts by mass of pure Zn, the amounts of other components in the high-strength zinc alloy material are as follows: 8 parts by mass of Al, 4 parts by mass of Cu, 2 parts by mass of Al-20Ti master alloy, 3 parts by mass of Al-10B master alloy, 4 parts by mass of Al-10V master alloy, and 0.1 parts by mass of pure Mg.

[0029] The preparation method of high-strength zinc alloy material 1 includes the following steps:

[0030] (1) Add pure Zn into a graphite crucible to melt. After observing the appearance of liquid zinc, add pure Cu to melt together. Then add charcoal covering material and heat to 650±3℃. After all Cu has melted, stir the molten metal to make the copper and zinc that have melted at the bottom of the crucible mix evenly. Then add pure Al.

[0031] (2) After all Al has been melted, the temperature is raised to 790℃. A bell jar is used to press the thin-sheet Al-10B, Al-10V and Al-20Ti master alloys into the liquid metal in sequence, close to the crucible wall, so that the heating is fast and the melting is accelerated.

[0032] (3) After all the added intermediate alloy has melted, stir the molten metal to mix it thoroughly and evenly, cool it down to 650±3℃, add pure Mg, after the Mg melts, let it stand for 5±1 minutes and then cool it down to 500±3℃, remove the slag, and pour it into a metal mold with a mold temperature of room temperature. When the mold temperature is less than 150℃, open the mold and take out the cast Zn alloy 1, and let it cool naturally in the environment.

[0033] (4) The as-cast Zn alloy was solution-treated at 360°C for 6 hours and then water-cooled to obtain high-strength zinc alloy material 1.

[0034] Example 2

[0035] Based on 100 parts by mass of pure Zn, the amounts of other components in the high-strength zinc alloy material are as follows: 6 parts by mass of Al, 6 parts by mass of Cu, 4 parts by mass of Al-20Ti master alloy, 4 parts by mass of Al-10B master alloy, 2 parts by mass of Al-10V master alloy, 1 part by mass of Al-25Sr master alloy, and 0.15 parts by mass of pure Mg.

[0036] The preparation method of high-strength zinc alloy material 2 includes the following steps:

[0037] (1) Add pure Zn into a graphite crucible to melt. After observing the appearance of liquid zinc, add pure Cu to melt together. Then add charcoal covering material and heat to 650±3℃. After all Cu has melted, stir the molten metal to make the copper and zinc that have melted at the bottom of the crucible mix evenly. Then add pure Al.

[0038] (2) After all Al has been melted, the temperature is raised to 780°C. A bell jar is used to press the thin-sheet Al-10B, Al-10V and Al-20Ti master alloys into the liquid metal in sequence, close to the crucible wall, so that the heating is fast and the melting is accelerated.

[0039] (3) After all the intermediate alloy has been added, stir the molten metal to make it fully mixed and uniform. Cool it down to 650±3℃, add pure Mg. After the Mg melts, let it stand for 5±1 minutes and then cool it down to 500±3℃. Remove the slag and pour it into a metal mold with a mold temperature of room temperature. When the mold temperature is less than 150℃, open the mold and take out the cast Zn alloy 2. Let it cool naturally in the environment.

[0040] (4) The as-cast Zn alloy 2 was solution-treated at 340℃ for 3 hours and then water-cooled to obtain high-strength zinc alloy material 2.

[0041] Example 3

[0042] Based on 100 parts by mass of pure Zn, the amounts of other components in the high-strength zinc alloy material are as follows: 7 parts by mass of Al, 5 parts by mass of Cu, 3 parts by mass of Al-20Ti master alloy, 2 parts by mass of Al-10B master alloy, 3 parts by mass of Al-10V master alloy, 4 parts by mass of Al-25Sr master alloy, and 0.1 parts by mass of pure Mg.

[0043] The preparation method of high-strength zinc alloy material 3 includes the following steps:

[0044] (1) Add pure Zn into a graphite crucible to melt. After observing the appearance of liquid zinc, add pure Cu to melt together. Then add charcoal covering material and heat to 650±3℃. After all Cu has melted, stir the molten metal to make the copper and zinc that have melted at the bottom of the crucible mix evenly. Then add pure Al.

[0045] (2) After all Al has been melted, the temperature is raised to 750°C. A bell jar is used to press the thin-sheet Al-10B, Al-10V and Al-20Ti master alloys into the liquid metal in sequence, close to the crucible wall, so that the heating is fast and the melting is accelerated.

[0046] (3) After all the intermediate alloy has been added, stir the molten metal to make it fully mixed and uniform. Cool it down to 650±3℃, add pure Mg. After the Mg melts, let it stand for 5±1 minutes and then cool it down to 500±3℃. Remove the slag and pour it into a metal mold with a mold temperature of room temperature. When the mold temperature is less than 150℃, open the mold and take out the cast Zn alloy 3. Let it cool naturally in the environment.

[0047] (4) The as-cast Zn alloy 3 was solution-treated at 300℃ for 9 hours and then water-cooled to obtain high-strength zinc alloy material 3.

[0048] Comparative Example 1

[0049] Based on 100 parts by mass of pure Zn, the amounts of other components in the high-strength zinc alloy material are as follows: 10 parts by mass of Al, 1 part by mass of Cu, 4 parts by mass of Al-20Ti master alloy, 2 parts by mass of Al-10B master alloy, 1 part by mass of Al-10V master alloy, and 0.5 parts by mass of pure Mg.

[0050] (1) Add pure Zn into a graphite crucible to melt. After observing the appearance of liquid zinc, add pure Cu to melt together. Then add charcoal covering material and heat to 650±3℃. After all Cu has melted, stir the molten metal to make the copper and zinc that have melted at the bottom of the crucible mix evenly. Then add pure Al.

[0051] (2) After all Al has been melted, the temperature is raised to 790℃. A bell jar is used to press the thin sheet-like Al-10B, Al-10V and Al-20Ti intermediate alloys into the liquid metal in sequence, close to the crucible wall, so that the heating is fast and the melting is accelerated.

[0052] (3) After all the added intermediate alloy has been melted, stir the molten metal to make it fully mixed and uniform. Cool down to 650±3℃, add pure Mg, melt and stand for 5±1 minutes, then cool down to 500±3℃, remove the slag, and pour into a metal mold with a mold temperature of room temperature. When the mold temperature is less than 150℃, open the mold and take out the cast Zn alloy 4, and let it cool naturally in the environment.

[0053] (4) The as-cast Zn alloy 3 was solution-treated at 360°C for 6 hours and then cooled with water to obtain zinc alloy material 4.

[0054] Comparative Example 2

[0055] Based on 100 parts by mass of pure Zn, the amounts of other components in the high-strength zinc alloy material are as follows: 2 parts by mass of Al, 8 parts by mass of Cu, 6 parts by mass of Al-20Ti master alloy, 4 parts by mass of Al-10B master alloy, 3 parts by mass of Al-10V master alloy, 1 part by mass of Mg, and 0.5 parts by mass of Al-25Sr master alloy.

[0056] (1) Add pure Zn into a graphite crucible to melt. After observing the appearance of liquid zinc, add pure Cu to melt together. Then add charcoal covering material and heat to 650±3℃. After all Cu has melted, stir the molten metal to make the copper and zinc that have melted at the bottom of the crucible mix evenly. Then add pure Al.

[0057] (2) After all Al has been melted, the temperature is raised to 790℃. A bell-shaped Al-10B, Al-10V and Al-20Ti intermediate alloy is pressed into the liquid metal and placed close to the crucible wall to make the heating faster and accelerate the melting.

[0058] (3) After all the added intermediate alloy has melted, stir the molten metal to mix it thoroughly and evenly, cool it down to 650±3℃, add pure Mg, after the Mg melts, let it stand for 5±1 minutes and then cool it down to 500±3℃, remove the slag, and pour it into a metal mold with a mold temperature of room temperature. When the mold temperature is less than 150℃, open the mold and take out the cast Zn alloy 4, and let it cool naturally in the environment.

[0059] (4) The as-cast Zn alloy 4 was solution-treated at 360°C for 6 hours and then water-cooled to obtain zinc alloy material 5.

[0060] Effect Example

[0061] 1. Samples of the as-cast Zn alloy 1 and high-strength zinc alloy material 1 prepared in Example 1 were taken and photographed for observation. The results are as follows: Figures 1-4 As shown. Figure 1 , Figure 2 The images are metallographic photographs of as-cast Zn alloy 1 and high-strength zinc alloy material 1, respectively. As-cast Zn alloy 1 consists of bright white granular zinc solid solution and light-colored zinc-aluminum eutectic, while high-strength zinc alloy material 1 consists of gray zinc-aluminum eutectic, black zinc-copper-aluminum compound and a small amount of white granular zinc-copper compound. Figure 3 , Figure 4 The room temperature tensile fracture morphologies of as-cast Zn alloy 1 and high-strength zinc alloy 1 are shown respectively. Among them, the fracture surface of high-strength zinc alloy 1 has the characteristic of significantly fine grains.

[0062] 2. The as-cast Zn alloy and zinc alloy materials obtained in Examples 1-3, Comparative Example 1, and Comparative Example 2 were subjected to performance tests (GB / T 228.1-2010, "Metallic Materials - Tensile Testing - Part 1: Test Method at Room Temperature"). The test results were compared, and the results are shown in Table 1 below.

[0063] Table 1 Comparison of alloy properties between implementation cases and comparative examples

[0064]

[0065] As shown in Table 1, compared with Examples 1 to 3, the properties (including tensile strength) of the cast Zn alloy and zinc alloy materials in Comparative Examples 1 and 2 decreased significantly. This indicates that the proportion of each component in the high-strength zinc alloy material also plays an important role in the material properties, especially the tensile strength.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of producing a high-strength zinc alloy material, characterized by comprising: The method includes the following steps: ​ (1) Melt pure Zn in a graphite crucible, add pure Cu and charcoal covering, heat to 650±3℃, and after Cu has completely melted, stir and mix evenly, then add pure Al; (2) After all the pure Cu and Al have been purified, the temperature is raised to 750~790℃, and the thin sheet-like intermediate alloy is pressed into the liquid metal; the intermediate alloy is composed of Al-10B, Al-10V and Al-20Ti. (3) After all the added intermediate alloys have been completely melted, stir evenly, cool down to 650±3℃, add pure Mg, after Mg melts, stir and mix evenly, let stand for 5±1 minutes, cool down to 500±3℃, remove slag, pour into a metal mold with room temperature, and when the mold temperature is less than 150℃, open the mold and take out the cast Zn alloy, and let it cool naturally. (4) The as-cast Zn alloy is solution-treated at 300~360℃ for 3~9 hours and then water-cooled to obtain a high-strength zinc alloy material; in the high-strength zinc alloy material, based on 100 parts by mass of pure Zn, the mass parts of other components in the material are: 4~6 parts by mass of Cu, 6~8 parts by mass of Al, 2~4 parts by mass of Al-10B master alloy, 2~4 parts by mass of Al-10V master alloy, 2~4 parts by mass of Al-20Ti master alloy, and 0.1~0.15 parts by mass of pure Mg.

2. The method of claim 1, wherein, In the high-strength zinc alloy material, based on 100 parts by mass of pure Zn, the mass parts of other components in the material are as follows: 4 parts by mass of Cu, 8 parts by mass of Al, 3 parts by mass of Al-10B master alloy, 4 parts by mass of Al-10V master alloy, 2 parts by mass of Al-20Ti master alloy, and 0.1 parts by mass of pure Mg.

3. The method as described in claim 1, characterized in that, In step (4), the as-cast Zn alloy is solution-treated and held at 340℃~360℃ for 3~6 hours.

4. The method of claim 3, wherein, In step (4), the as-cast Zn alloy is solution-treated and held at 360°C for 6 hours.

5. The method of claim 1, wherein, In step (2), the intermediate alloy further includes Al-25Sr; wherein, in the high-strength zinc alloy material, the mass part of Al-25Sr intermediate alloy is 1~4 based on 100 parts by mass of pure Zn.

6. The method of claim 5, wherein, The thicknesses of the Al-10B, Al-10V, Al-20Ti, and Al-25Sr master alloys are all 2 mm.

7. The high-strength zinc alloy material prepared by the method according to any one of claims 1 to 6.

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