Heat-treated dual-phase magnesium alloy and method for improving hydrogen production performance of dual-phase magnesium alloy containing lpso phase

Abstract

The application discloses a heat-treated dual-phase magnesium alloy and a method for improving the hydrogen production performance of a dual-phase magnesium alloy containing an LPSO phase, wherein the as-cast dual-phase magnesium alloy is heat-treated at 520-540 DEG C for 2-4 hours, the hydrogen production rate of the heat-treated alloy in simulated seawater is significantly improved, and the hydrogen production rate in 25 minutes can reach more than 97%. The chemical composition of the as-cast alloy is Mg (100‑x‑y) Y x Ni y , 0.6≦x≦2.2, 0.8≦y≦1.4, containing Mg phase and LPSO phase with continuous network morphology. The application changes the LPSO phase morphology in the dual-phase magnesium alloy into discontinuous needle rod shape through heat treatment, weakens the "barrier" effect of corrosion on the Mg phase, and thus realizes high-efficiency hydrogen production. The application optimizes the performance of the bulk alloy through heat treatment instead of optimizing the powder alloy, which not only can reduce the cost of mass production and preparation, but also is beneficial to the transportation and storage of the magnesium-based hydrogen production alloy by hydrolysis, avoids the problems of easy oxidation and difficult transportation and storage of the powder sample, and is beneficial to practical application.

Description

Technical Field

[0001] This invention relates to a method for improving the hydrogen production performance of dual-phase magnesium alloys containing LPSO phase through hydrolysis, belonging to the field of magnesium-based hydrogen production technology. Background Technology

[0002] Magnesium-based hydrolysis hydrogen production materials can produce hydrogen in seawater at room temperature through hydrolysis. The hydrolysis products are pollution-free and can be reused in the regeneration of magnesium, making them an ideal material for both hydrogen storage and production. However, the hydrolysis product Mg(OH)₂ of magnesium-based materials forms a dense passivation film on the surface, hindering the reaction and resulting in low hydrogen production efficiency. Studies have shown that alloying can create a second phase within the material. This second phase interacts with the magnesium matrix to form an galvanic corrosion effect, which can improve the hydrogen production performance of the alloy to some extent.

[0003] The LPSO second phase within the Mg-Y-Ni dual-phase alloy can form an galvanic corrosion barrier with the Mg matrix. However, due to the more positive corrosion potential of LPSO, it is more corrosion-resistant than Mg and exhibits a continuous network morphology within the as-cast alloy, forming a "corrosion barrier" that hinders the continued hydrolysis reaction, often preventing the achievement of higher hydrogen production efficiency. Among the Mg-Y-Ni dual-phase alloys prepared by Legree M et al., Mg exhibits the best hydrogen production performance through hydrolysis. 87.6 Ni 5.5 Y 6.9 The hydrogen production efficiency of the alloy at 40 minutes was only 87.5%. This may be because the LPSO phase encapsulates the Mg phase, which acts as a "barrier" against Mg phase corrosion and hinders the hydrolysis process of the alloy (International Journal of Hydrogen Energy, 46(71), 35161-35171, 2021). Heat treatment can often improve the microstructure of the alloy. Therefore, heat treatment is expected to regulate the microstructure of magnesium-based hydrolysis hydrogen production alloys and improve the hydrogen production efficiency of the material. Summary of the Invention

[0004] To address the technical problems in hydrogen production efficiency of magnesium-based hydrolysis hydrogen production materials, the present invention aims to overcome the shortcomings of existing technologies and provide a heat-treated duplex magnesium alloy and a method for improving the hydrolysis hydrogen production performance of duplex magnesium alloys containing LPSO phase. The morphology of the LPSO phase is controlled by heat treatment, thereby obtaining rapid and efficient hydrogen production performance.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A heat-treatable duplex magnesium alloy is obtained by heating a cast duplex magnesium alloy to 520–540°C and holding it for 2–4 hours under vacuum or argon protection, resulting in a heat-treatable duplex magnesium alloy with excellent hydrolytic properties; wherein the cast duplex magnesium alloy has a chemical composition of Mg. (100-x-y) Y x Ni y The dual-phase magnesium alloy comprises a Mg phase and a continuous network LPSO phase, and satisfies 0.6≦x≦2.2 and 0.8≦y≦1.4. The heat-treated dual-phase magnesium alloy differs from the cast dual-phase magnesium alloy in that the LPSO phase exhibits a continuous network morphology, while the heat-treated dual-phase magnesium alloy has a discontinuous needle-like LPSO phase.

[0007] Preferably, the LPSO phase in the heat-treated duplex magnesium alloy is discontinuous and needle-like, with 90% of the LPSO phase having a length and width not exceeding 200 μm and 30 μm respectively; and the aspect ratio of 90% of the needle-like LPSO phase is ≥2.

[0008] Preferably, the LPSO phase in the heat-treated duplex magnesium alloy is discontinuous and needle-like, with 90% of the LPSO phase having a length and width of 20-200 μm and 2-30 μm, respectively; the aspect ratio of the 90% needle-like LPSO phase is 2-20.

[0009] Preferably, the heat-treated duplex magnesium alloy of the present invention is characterized by: 0.6≦x≦2.2, 0.8≦y≦1.4.

[0010] Preferably, the heat-treated duplex magnesium alloy powder is hydrolyzed in a NaCl solution with a mass percentage concentration of 3.5 wt.%, and at room temperature, the hydrogen production volume expressed as hydrogen production per gram of heat-treated duplex magnesium alloy hydrolysis is not less than 910.3 mL, and the hydrogen yield is not less than 97%.

[0011] More preferably, the heat-treated duplex magnesium alloy powder is hydrolyzed in a 3.5 wt.% NaCl solution. At room temperature, the hydrogen production per gram of heat-treated duplex magnesium alloy hydrolyzed to produce hydrogen is 910.3-977.9, and the hydrogen yield is 97.9%-100%.

[0012] A method for improving the hydrogen production performance of LPSO-containing duplex magnesium alloys via hydrolysis, comprising the following steps:

[0013] A heat-treated duplex magnesium alloy with excellent hydrolytic properties is obtained by heating a cast duplex magnesium alloy to 520–540°C and holding it for 2–4 hours under vacuum or argon protection; wherein the cast duplex magnesium alloy has a chemical composition of Mg. (100-x-y) Y x Ni yThe dual-phase magnesium alloy comprises a Mg phase and a continuous network LPSO phase, and satisfies 0.6≦x≦2.2 and 0.8≦y≦1.4. The heat-treated dual-phase magnesium alloy differs from the cast dual-phase magnesium alloy in that the LPSO phase exhibits a continuous network morphology, while the heat-treated dual-phase magnesium alloy has a discontinuous needle-like LPSO phase.

[0014] Preferably, the preparation of the as-cast duplex magnesium alloy for heat treatment includes the following specific steps: Mg blocks, Ni particles, and Mg-20Y master alloy are mixed and added to a graphite crucible, and then repeatedly melted at least three times by high-frequency vacuum melting. The molten metal is then poured into a copper mold and cooled to obtain the as-cast duplex magnesium alloy.

[0015] Compared with the prior art, the present invention has the following obvious and prominent substantive features and significant advantages:

[0016] 1. The heat-treated duplex magnesium alloy described in this invention has excellent hydrolytic properties. Unlike the continuous network morphology of the LPSO phase in the as-cast alloy, the LPSO phase in the heat-treated duplex magnesium alloy is discontinuous needle-rod morphology.

[0017] 2. This invention modifies the morphology of the LPSO phase in a magnesium-based dual-phase hydrolysis hydrogen production alloy by heat treatment, transforming it from a continuous network to a discontinuous needle-rod shape. The needle-rod shape weakens the "barrier" effect of the continuous network LPSO phase on the corrosion of the Mg phase, significantly improving the efficiency of hydrogen production by hydrolysis of the dual-phase magnesium alloy.

[0018] 3. This invention modifies the morphology of the LPSO phase in the Mg-Y-Ni dual-phase alloy by heat treatment, transforming it from a continuous network to a discontinuous needle-rod shape. This weakens the inhibitory effect of the continuous network LPSO on Mg corrosion. While possessing the advantage of improving the hydrolysis rate by reducing galvanic corrosion in dual-phase alloys, it also significantly improves the hydrogen yield and increases the hydrogen production mass density of the material.

[0019] 4. This invention optimizes the performance of bulk alloys through heat treatment, rather than optimizing powder alloys. This not only reduces the cost of mass production, but also facilitates the transportation and storage of magnesium-based hydrolysis hydrogen production alloys, avoiding the problems of easy oxidation and difficulty in transportation and storage of powder samples, which is beneficial for practical applications. Attached Figure Description

[0020] Figure 1 For Comparative Example 1, the as-cast alloy Mg 97.3 Y 1.9 Ni 0.8 SEM image.

[0021] Figure 2 The alloy Mg of Example 1 of this invention was heat-treated at 540°C for 4 hours.97.3 Y 1.9 Ni 0.8 SEM image.

[0022] Figure 3 This is a comparison curve of the hydrogen production rate by hydrolysis at room temperature between the heat-treated alloy in the embodiment of the present invention and the as-cast alloy in the comparative example.

[0023] Figure 4 This is a comparison chart of the hydrogen production yield curves of the heat-treated alloy and the as-cast alloy in the comparative example at room temperature. Detailed Implementation

[0024] The above solution will be further described below with reference to specific embodiments. The preferred embodiments of the present invention are described in detail below:

[0025] Example 1

[0026] In this embodiment, a method for preparing a heat-treated duplex magnesium alloy to improve the hydrogen production performance of a duplex magnesium alloy containing LPSO phase via hydrolysis includes the following steps:

[0027] Mg blocks, Ni granules, and Mg-20Y master alloy were mixed and added to a graphite crucible. The mixture was repeatedly melted three times using high-frequency vacuum melting. The molten metal was then poured into a copper mold and cooled to obtain as-cast dual-phase magnesium alloy Mg. 97.3 Y 1.9 Ni 0.8 Its SEM image is as follows Figure 1 As shown, it contains a Mg phase and a continuous network LPSO phase. The as-cast dual-phase magnesium alloy contains Mg. 97.3 Y 1.9 Ni 0.8 After being heated to 540℃ under vacuum, the alloy was held at that temperature for 4 hours, and then cooled to room temperature in the furnace. The SEM image of the heat-treated alloy is shown below. Figure 2 As shown, the LPSO phase in the alloy transforms into a discontinuous needle-like morphology. In the heat-treated dual-phase magnesium alloy, the LPSO phase is discontinuous and needle-like, with 90% of the needles having a length and width not exceeding 100 μm and 20 μm, respectively; 90% of the needle-like LPSO has an aspect ratio ≥2.

[0028] Both as-cast and heat-treated alloy powders were hydrolyzed in a 3.5 wt.% NaCl solution. The hydrogen production curves and hydrolysis rate curves are shown below. Figure 3 and Figure 4 As shown, the heat-treated alloy Mg 97.3 Y 1.9 Ni 0.8 It can be completely hydrolyzed within 20 minutes, producing 944.5 ml / g of hydrogen gas, with a hydrogen yield of 100%, while the as-cast alloy Mg... 97.3 Y1.9 Ni 0.8 The hydrolysis rate is only 82.8%.

[0029] In this embodiment, the LPSO phase in the heat-treated duplex magnesium alloy and the cast duplex magnesium alloy exhibit a different continuous network morphology. The LPSO phase in the heat-treated duplex magnesium alloy is discontinuous and needle-like. This embodiment modifies the morphology of the LPSO phase in a magnesium-based dual-phase hydrolysis hydrogen production alloy by heat treatment, transforming it from a continuous network to a discontinuous needle-like structure. The needle-like morphology weakens the "barrier" effect of the continuous network LPSO phase on the corrosion of the Mg phase, significantly improving the efficiency of hydrogen production through hydrolysis of the dual-phase magnesium alloy. This embodiment changes the morphology of the LPSO phase in the Mg-Y-Ni dual-phase alloy through heat treatment, weakening the hindering effect of the continuous network LPSO on Mg corrosion. While maintaining the advantage of improved hydrolysis rate due to galvanic corrosion in dual-phase alloys, it also significantly increases hydrogen yield and improves the hydrogen production density of the material. This embodiment optimizes the performance of the bulk alloy through heat treatment, rather than optimizing the powder alloy. This not only reduces the cost of mass production but also facilitates the transportation and storage of the magnesium-based hydrolysis hydrogen production alloy, avoiding the problems of easy oxidation and difficulty in transportation and storage of powder samples, thus benefiting practical applications.

[0030] Example 2

[0031] This embodiment is basically the same as Embodiment 1, except that:

[0032] In this embodiment, an improvement method for hydrogen production performance of dual-phase magnesium alloys containing LPSO phase through hydrolysis includes the following steps:

[0033] Mg blocks, Ni granules, and Mg-20Y master alloy were mixed and added to a graphite crucible. The mixture was repeatedly melted three times using high-frequency vacuum melting. The molten metal was then poured into a copper mold and cooled to obtain as-cast dual-phase magnesium alloy Mg. 98.6 Y 0.6 Ni 0.8 Its microstructure comprises a Mg phase and a continuous network LPSO phase. The as-cast dual-phase magnesium alloy Mg... 98.6 Y 0.6 Ni 0.8 After being heated to 540°C in a vacuum and held for 4 hours, the alloy was then cooled to room temperature in the furnace. After heat treatment, the LPSO phase in the alloy transformed into a discontinuous needle-like morphology.

[0034] Both as-cast and heat-treated alloy powders were hydrolyzed in a 3.5 wt.% NaCl solution. The hydrogen production curves and hydrolysis rate curves are shown below. Figure 3 and Figure 4 As shown, the heat-treated alloy Mg 98.6Y 0.6 Ni 0.8 The hydrolysis was almost complete within 15 minutes, producing 977.9 ml / g of hydrogen gas, with a hydrogen yield of 98.8%, which is higher than the hydrolysis rate of the as-cast alloy (93.9%). The above embodiments of the present invention significantly improve the hydrogen production performance of the hydrolysis by heat-treating the LPSO-containing duplex magnesium alloy, changing the LPSO phase morphology from a network to a needle-like structure. Furthermore, the preparation method is simple and easy to implement.

[0035] Example 3

[0036] This embodiment is basically the same as the above embodiments, except that:

[0037] In this embodiment, an improvement method for hydrogen production performance of dual-phase magnesium alloys containing LPSO phase through hydrolysis includes the following steps:

[0038] Mg blocks, Ni granules, and Mg-20Y master alloy were mixed and added to a graphite crucible. The mixture was repeatedly melted three times using high-frequency vacuum melting. The molten metal was then poured into a copper mold and cooled to obtain as-cast dual-phase magnesium alloy Mg. 97.3 Y 1.9 Ni 0.8 Its microstructure comprises a Mg phase and a continuous network LPSO phase. The as-cast dual-phase magnesium alloy Mg... 97.3 Y 1.9 Ni 0.8 After being heated to 520°C in a vacuum and held for 4 hours, the alloy was then cooled to room temperature in the furnace. After heat treatment, the LPSO phase in the alloy transformed into a discontinuous needle-like morphology.

[0039] Both as-cast and heat-treated alloy powders were hydrolyzed in a 3.5 wt.% NaCl solution. The hydrogen production curves and hydrolysis rate curves are shown below. Figure 3 and Figure 4 As shown, the heat-treated alloy Mg 97.3 Y 1.9 Ni 0.8 The hydrolysis was almost complete within 20 minutes, producing 939.2 ml / g of hydrogen gas, with a hydrogen yield of 99.4%. The hydrogen production yield from hydrolysis was increased by 16.6% compared to the as-cast alloy. The above embodiments of the present invention significantly improved the hydrogen production performance of the LPSO-containing duplex magnesium alloy by heat-treating it, changing the LPSO phase morphology from a network to a needle-like structure. Furthermore, the preparation method is simple and easy to implement.

[0040] Example 4

[0041] This embodiment is basically the same as the above embodiments, except that:

[0042] In this embodiment, an improvement method for hydrogen production performance of dual-phase magnesium alloys containing LPSO phase through hydrolysis includes the following steps:

[0043] In this embodiment, Mg blocks, Ni granules, and Mg-20Y master alloy are mixed and added to a graphite crucible. The mixture is then repeatedly melted three times using high-frequency vacuum melting. The molten metal is poured into a copper mold and cooled to obtain a cast dual-phase magnesium alloy Mg. 97.3 Y 1.9 Ni 0.8 Its microstructure comprises a Mg phase and a continuous network LPSO phase. The as-cast dual-phase magnesium alloy Mg... 97.3 Y 1.9 Ni 0.8 After being heated to 540°C in a vacuum and held for 2 hours, the alloy was then cooled to room temperature in the furnace. After heat treatment, the LPSO phase in the alloy transformed into a discontinuous needle-like morphology.

[0044] Both as-cast and heat-treated alloy powders were hydrolyzed in a 3.5 wt.% NaCl solution. The hydrogen production curves and hydrolysis rate curves are shown below. Figure 3 and Figure 4 As shown, the heat-treated alloy Mg 97.3 Y 1.9 Ni 0.8 The hydrolysis was almost complete within 24 minutes, producing 925.3 ml / g of hydrogen, with a hydrogen yield of 97.9%. The hydrogen production yield from hydrolysis was increased by 15% compared to the as-cast alloy. The above embodiments of the present invention significantly improved the hydrogen production performance of the LPSO-containing duplex magnesium alloy by heat-treating it, changing the LPSO phase morphology from a network to a needle-like structure. Furthermore, the preparation method is simple and easy to implement.

[0045] Example 5

[0046] This embodiment is basically the same as the above embodiments, except that:

[0047] In this embodiment, an improvement method for hydrogen production performance of dual-phase magnesium alloys containing LPSO phase through hydrolysis includes the following steps:

[0048] In this embodiment, Mg blocks, Ni granules, and Mg-20Y master alloy were mixed and added to a graphite crucible. Under argon protection, the mixture was repeatedly melted three times by high-frequency melting. The molten metal was then poured into a copper mold and cooled to obtain a cast dual-phase magnesium alloy Mg. 96.4 Y 2.2 Ni 1.4 Its microstructure comprises a Mg phase and a continuous network LPSO phase. The as-cast dual-phase magnesium alloy Mg... 96.4 Y 2.2 Ni 1.4 After being heated to 540°C in a vacuum and held for 2 hours, the alloy was then cooled to room temperature in the furnace. After heat treatment, the LPSO phase in the alloy transformed into a discontinuous needle-like morphology.

[0049] Both as-cast and heat-treated alloy powders were hydrolyzed in a 3.5 wt.% NaCl solution. The heat-treated alloy Mg... 96.4 Y 2.2 Ni 1.4 The hydrolysis was almost complete within 25 minutes, producing 910.3 ml / g of hydrogen, with a hydrogen yield of 98.7%. The hydrogen production yield from hydrolysis was increased by 2.7% compared to the as-cast alloy. The above embodiments of the present invention significantly improved the hydrogen production performance of the LPSO-containing duplex magnesium alloy by heat-treating it to change the LPSO phase morphology from a network to a needle-like structure. Furthermore, the preparation method is simple and easy to implement.

[0050] Example 6

[0051] This embodiment is basically the same as the above embodiments, except that:

[0052] In this embodiment, an improvement method for hydrogen production performance of dual-phase magnesium alloys containing LPSO phase through hydrolysis includes the following steps:

[0053] In this embodiment, Mg blocks, Ni granules, and Mg-20Y master alloy were mixed and added to a graphite crucible. Under argon protection, the mixture was repeatedly melted three times by high-frequency melting. The molten metal was then poured into a copper mold and cooled to obtain a cast dual-phase magnesium alloy Mg. 98.6 Y 0.6 Ni 0.8 Its microstructure comprises a Mg phase and a continuous network LPSO phase. The as-cast dual-phase magnesium alloy Mg... 98.6 Y 0.6 Ni 0.8 After being heated to 540°C in a vacuum and held for 2 hours, the alloy was then cooled to room temperature in the furnace. After heat treatment, the LPSO phase in the alloy transformed into a discontinuous needle-like morphology.

[0054] Both as-cast and heat-treated alloy powders were hydrolyzed in a 3.5 wt.% NaCl solution. The heat-treated alloy Mg... 98.6 Y 0.6 Ni 0.8 The hydrolysis was almost complete within 18 minutes, producing 969.4 ml / g of hydrogen, with a hydrogen yield of 97.9%. The hydrogen production yield from hydrolysis was increased by 3.9% compared to the as-cast alloy. The above embodiments of the present invention significantly improved the hydrogen production performance of the LPSO-containing duplex magnesium alloy by heat-treating it to change the LPSO phase morphology from a network to a needle-like structure. Furthermore, the preparation method is simple and easy to implement.

[0055] Comparative Example 1

[0056] In the comparative example, Mg blocks, Ni granules, and Mg-20Y master alloy were mixed and added to a graphite crucible. The mixture was repeatedly melted three times using high-frequency vacuum melting. The molten metal was then poured into a copper mold and cooled to obtain a cast dual-phase magnesium alloy Mg. 97.3 Y 1.9 Ni 0.8 Its structure includes a Mg phase and a continuous network LPSO phase, such as Figure 1 As shown in the figure. The as-cast alloy powder was hydrolyzed in a 3.5 wt.% NaCl solution, and the hydrogen production curve and hydrolysis rate curve are shown in the figure. Figure 3 and Figure 4 As shown, only 782.6 ml / g of hydrogen was produced after 30 minutes, with a hydrogen yield of only 82.8%.

[0057] Comparative Example 2

[0058] In the comparative example, Mg blocks, Ni granules, and Mg-20Y master alloy were mixed and added to a graphite crucible. The mixture was repeatedly melted three times using high-frequency vacuum melting. The molten metal was then poured into a copper mold and cooled to obtain a cast dual-phase magnesium alloy Mg. 98.6 Y 0.6 Ni 0.8 Its microstructure includes a Mg phase and a continuous network LPSO phase. The as-cast alloy powder was hydrolyzed in a 3.5 wt.% NaCl solution, and the hydrogen production curve and hydrolysis rate curve are shown below. Figure 3 and Figure 4 As shown, 930.2 ml / g of hydrogen was produced after 30 minutes, with a hydrogen yield of 93.9%.

[0059] In summary, the method described above for improving the hydrogen production performance of LPSO-containing duplex magnesium alloys involves heat-treating the as-cast duplex magnesium alloy at 520–540°C for 2–4 hours. The heat-treated alloy exhibits a significantly improved hydrogen production rate through hydrolysis in simulated seawater, reaching over 97% within 25 minutes. The as-cast alloy has a chemical composition of Mg. (100-x-y) Y x Ni y The alloy contains 0.6≦x≦2.2, 0.8≦y≦1.4, and includes both a Mg phase and a continuous network LPSO phase. The advantage of the above embodiments of the present invention lies in transforming the LPSO phase morphology in the dual-phase magnesium alloy into a discontinuous needle-like shape through heat treatment, weakening the "barrier" effect against Mg phase corrosion, thereby achieving high-efficiency hydrogen production. The above embodiments of the present invention optimize the performance of the bulk alloy through heat treatment, rather than optimizing the powder alloy. This not only reduces the cost of mass production but also facilitates the transportation and storage of magnesium-based hydrolysis hydrogen production alloys, avoiding the problems of easy oxidation and difficulty in transportation and storage of powder samples, thus benefiting practical applications.

[0060] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made according to the purpose of the invention. Any changes, modifications, substitutions, combinations or simplifications made based on the spirit and principle of the technical solution of the present invention shall be equivalent substitutions. As long as they meet the purpose of the invention and do not deviate from the technical principle and inventive concept of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A heat-treatable duplex magnesium alloy, characterized in that: A heat-treated duplex magnesium alloy with excellent hydrolytic properties is obtained by heating a cast duplex magnesium alloy to 520–540°C and holding it for 2–4 hours under vacuum or argon protection; wherein the cast duplex magnesium alloy has a chemical composition of Mg. (100-x-y) Y x Ni y The dual-phase magnesium alloy comprises a Mg phase and a continuous network LPSO phase, and satisfies 0.6≦x≦2.2 and 0.8≦y≦1.

4. The heat-treated dual-phase magnesium alloy differs from the cast dual-phase magnesium alloy in that the LPSO phase exhibits a continuous network morphology, while the heat-treated dual-phase magnesium alloy has a discontinuous needle-like LPSO phase.

2. The heat-treated duplex magnesium alloy according to claim 1, characterized in that: In the heat-treated duplex magnesium alloy, the LPSO phase is discontinuous and needle-like. 90% of the LPSO phases have a length and width of no more than 200 μm and no more than 30 μm, respectively; the aspect ratio of 90% of the needle-like LPSO phases is ≥2.

3. The heat-treated duplex magnesium alloy according to claim 1, characterized in that: In the heat-treated dual-phase magnesium alloy, the LPSO phase is discontinuous and needle-like, with 90% of the LPSO phase having a length and width of 20-200 μm and 2-30 μm, respectively; the aspect ratio of 90% of the needle-like LPSO phase is 2-20.

4. The heat-treated duplex magnesium alloy according to claim 1, characterized in that: 1.9≦x≦2.2,0.8≦y≦1.4。 5. The heat-treated duplex magnesium alloy according to claim 1, characterized in that: The heat-treated duplex magnesium alloy powder is hydrolyzed in a 3.5 wt.% NaCl solution. At room temperature, the hydrogen production per gram of heat-treated duplex magnesium alloy hydrolyzed to produce hydrogen is not less than 910.3 mL / g, and the hydrogen yield is not less than 97%.

6. The heat-treated duplex magnesium alloy according to claim 5, characterized in that: The heat-treated duplex magnesium alloy powder was hydrolyzed in a 3.5 wt.% NaCl solution. At room temperature, the hydrogen production per gram of heat-treated duplex magnesium alloy hydrolyzed was 910.3-977.9 mL / g, and the hydrogen yield was 97.9%-100%.

7. A method for improving the hydrogen production performance of a dual-phase magnesium alloy containing LPSO phase via hydrolysis, comprising preparing a heat-treated dual-phase magnesium alloy, characterized in that... Includes the following steps: A heat-treated duplex magnesium alloy with excellent hydrolytic properties is obtained by heating a cast duplex magnesium alloy to 520–540°C and holding it for 2–4 hours under vacuum or argon protection; wherein the cast duplex magnesium alloy has a chemical composition of Mg. (100-x-y) Y x Ni y The dual-phase magnesium alloy comprises a Mg phase and a continuous network LPSO phase, and satisfies 0.6≦x≦2.2 and 0.8≦y≦1.

4. The heat-treated dual-phase magnesium alloy differs from the cast dual-phase magnesium alloy in that the LPSO phase exhibits a continuous network morphology, while the heat-treated dual-phase magnesium alloy has a discontinuous needle-like LPSO phase.

8. The method for improving the hydrogen production performance of dual-phase magnesium alloys containing LPSO phase according to claim 7, characterized in that: The preparation of the as-cast duplex magnesium alloy for heat treatment includes the following specific steps: Mg blocks, Ni particles, and Mg-20Y master alloy are mixed and added to a graphite crucible. The mixture is repeatedly melted at least three times by high-frequency vacuum melting. The molten metal is then poured into a copper mold and cooled to obtain the as-cast duplex magnesium alloy.

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