Ni-containing magnesium alloy material capable of rapidly hydrolyzing to produce hydrogen and preparation method thereof

Abstract

The application discloses a Ni-containing magnesium alloy material capable of rapidly hydrolyzing to produce hydrogen and a preparation method of the Ni-containing magnesium alloy material. The magnesium alloy material contains LPSO phases, Al2Y phases and Al3Y phases. The LPSO phase is composed of Y and Ni. According to mass percentage, the magnesium alloy material contains the following components: the LPSO phase is 7-28%, the Al2Y phase is 3-8%, the Al3Y phase is 1-5%, and the rest is magnesium and unavoidable impurity elements.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of magnesium alloy materials, in particular to a Ni-containing magnesium alloy material capable of rapidly producing hydrogen through hydrolysis and a preparation method thereof. BACKGROUND

[0002] Hydrogen energy is an important development goal of China's energy structure reform. To build a hydrogen energy society, it is necessary to solve and improve the problems of hydrogen energy production, storage, transportation and utilization, and on this basis, to develop high-energy, fast, portable and controllable hydrogen materials. The current mainstream methods for hydrogen production include photocatalysis, electrocatalysis and on-site hydrolysis. Compared with the first two methods, on-site hydrolysis has extremely low cost and easy-to-obtain raw materials, and it can be used immediately after production without the need for hydrogen storage. The on-site hydrolysis method using magnesium alloy materials as a medium can produce a large amount of hydrogen safely and reliably. It provides a new idea for solving the problems of low hydrogen energy power source, low efficiency and difficult storage, and optimizing hydrogen energy battery engines. Hydrogen energy engines can be applied to many scenarios, such as new energy vehicles, offshore work ships and submarines. China has abundant magnesium (Mg) resources and high hydrogen production capacity, and magnesium is considered to be a promising new energy material. The byproduct Mg(OH)2 formed during the hydrolysis process tends to quickly deposit on the surface of magnesium, hindering the direct contact between water and unreacted Mg, resulting in slow hydrolysis kinetics and even rapid termination. Therefore, destroying the magnesium oxide layer on the surface of Mg particles and the Mg(OH)2 formed during the hydrolysis reaction is the key to achieving rapid and complete hydrolysis of magnesium at room temperature. At the same time, increasing the diffusion channels and the contact area between reactants is the fundamental problem to be solved to improve the hydrogen production performance of magnesium alloys.

[0003] Ni-containing magnesium alloys have a relatively fast hydrolysis hydrogen release rate in aqueous solutions containing chloride ions. Further addition of alloying elements can regulate the hydrolysis hydrogen release rate. In the current research on the Mg-Y-Ni system, Mg-Ni compounds can to some extent destroy the continuity of the Mg(OH)2 film layer and promote the further formation of the reaction. However, the reaction rate of pure binary alloys still cannot meet the demand of practical application, and it is necessary to further develop new magnesium alloy materials with higher hydrolysis hydrogen release rate. SUMMARY

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a Ni-containing magnesium alloy material capable of rapidly producing hydrogen through hydrolysis and a preparation method thereof, so as to solve the problem of low hydrolysis hydrogen release rate of magnesium alloys in the prior art.

[0005] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0006] The application discloses a Ni-containing magnesium alloy material capable of rapidly hydrolyzing to produce hydrogen, wherein the magnesium alloy material contains LPSO phase, Al2Y phase and Al3Y phase; the LPSO phase is composed of Y and Ni; and the magnesium alloy material contains the following components in percentage by mass: 7-28% of the LPSO phase, 3-8% of the Al2Y phase, 1-5% of the Al3Y phase, and the balance of magnesium and unavoidable impurity elements.

[0007] Preferably, the mass ratio of the Y element to the Ni element is not less than 2.

[0008] Preferably, the mass ratio of the Al element to the Y element is not more than 1.

[0009] Preferably, the magnesium alloy material contains the following components in percentage by mass: 1-5% of Ni, 3-9% of Al and 1-8% of Y.

[0010] The application further provides a preparation method of the Ni-containing magnesium alloy material capable of rapidly hydrolyzing to produce hydrogen.

[0011] Step 1: calculation and preparation, after the pure magnesium is melted, the Mg-Ni intermediate alloy, the pure Al and the Mg-Y intermediate alloy are put together for smelting;

[0012] Step 2: the temperature is raised to 750-800 DEG C, and the alloy is slowly stirred until the alloy is melted, then the alloy is sufficiently alloyed, and is kept for 20-30 min, so as to obtain a magnesium alloy melt;

[0013] Step 3: the magnesium alloy melt obtained in step 2 is pressure cast into an ingot, so as to obtain the Ni-containing magnesium alloy material.

[0014] Preferably, in step 2, the temperature is raised to 750-780 DEG C.

[0015] Compared with the prior art, the application has the following beneficial effects:

[0016] The application adds the Al element on the basis of Mg-Y-Ni, forms the high-temperature stable phase Al2Y phase or Al3Y phase, the melting point of the compound is relatively high (higher than 900 DEG C), the Al-Y phase can be formed at the smelting temperature, the formation of the Al-Y phase can reduce the LPSO phase formed by Y and Ni, and can increase the formation of the new phase Al-Y phase; in this way, the LPSO phase effect can be better reserved, and the new phase can be increased to improve the hydrolysis reaction rate. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 SEM image of the magnesium alloy material prepared for Example 1. DETAILED DESCRIPTION

[0018] The application will be further described in connection with the examples.

[0019] A Ni-containing magnesium alloy material capable of rapidly hydrolyzing to produce hydrogen

[0020] The magnesium alloy material contains LPSO phase, Al2Y phase and Al3Y phase; the LPSO phase is composed of Y and Ni; the magnesium alloy material contains the following components in terms of mass percentage: 7% to 28% of LPSO phase, 3% to 8% of Al2Y phase, 1% to 5% of Al3Y phase, and the balance of magnesium and unavoidable impurity elements.

[0021] The application finds that, in the Mg-Y-Ni system, Y element can form a stacking ordered (LPSO) phase with Ni element, which can improve the rate of hydrolysis reaction to a certain extent, but the improvement effect is closely related to the content of Y element. The addition of Y element can help to a certain extent to solve the problem that the surface passivation layer hinders the reaction, but if the amount of Y element added is too much, the content of LPSO phase formed by Y element and Ni element will be too high, which will improve the corrosion resistance of the magnesium alloy material, which is very unfavorable for hydrolysis reaction. Therefore, the application adds Al element on the basis of Mg-Y-Ni, so that Al element and Y element form Al2Y phase and Al3Y phase, and the melting point of the two second phases is relatively high (higher than 900℃), which will be formed at the smelting temperature described in the application. The formation of this Al-Y phase can on the one hand reduce the amount of Y element participating in the formation of LPSO phase with Ni element to a certain extent, so that LPSO phase can better play its role and avoid its adverse effects; on the other hand, it can form new second phases (Al2Y phase and Al3Y phase), which can further improve the rate of hydrolysis reaction, and at the same time, the new second phase changes the morphology and distribution of LPSO phase to a certain extent, so that the required LPSO phase is formed in a more favorable direction for hydrolysis reaction. However, if the amount of new second phase is too much, the amount of LPSO phase formed by Y element and Ni element will be greatly reduced, which will in turn lead to a decrease in the rate of hydrolysis reaction, so the amount of Al-Y phase should not be too much.

[0022] In some embodiments, the content of the LPSO phase can be 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 18%, 20%, 25%, 28%, etc. in terms of mass percentage, and all ranges and sub-ranges between the above-mentioned values; the content of the Al2Y phase can be 3%, 4%, 5%, 6%, 7%, 8%, etc. in terms of mass percentage, and all ranges and sub-ranges between the above-mentioned values; the content of the Al3Y phase can be 1%, 2%, 3%, 4%, 5%, etc. in terms of mass percentage, and all ranges and sub-ranges between the above-mentioned values; it should be understood that, in embodiments, any of the above-mentioned ranges can be combined with any other range.

[0023] In some embodiments, the mass ratio of the Y element and the Ni element is not less than 2, so as to ensure that the magnesium alloy material can form a long-period stacking ordered LPSO phase during preparation.

[0024] In some embodiments, the mass ratio of the Al element and the Y element is not higher than 1, so as to provide sufficient Al element and ensure that the Al2Y phase and the Al3Y phase can be formed in sufficient amount.

[0025] In some embodiments, the magnesium alloy material contains the following components: Ni is 1-5%, Al is 3-9%, and Y is 1-8% in terms of mass percentage. The content of the Ni element can be 1%, 2%, 3%, 4%, 5%, etc. in terms of mass percentage, and all ranges and sub-ranges between the above-mentioned values; the content of the Al element can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc. in terms of mass percentage, and all ranges and sub-ranges between the above-mentioned values; the content of the Y element can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, etc. in terms of mass percentage, and all ranges and sub-ranges between the above-mentioned values; it should be understood that, in embodiments, any of the above-mentioned ranges can be combined with any other range.

[0026] II. A preparation method of a Ni-containing magnesium alloy material capable of rapidly hydrolyzing to produce hydrogen

[0027] The preparation of the above-mentioned Ni-containing magnesium alloy material capable of rapidly hydrolyzing to produce hydrogen specifically comprises the following steps:

[0028] Step 1: calculation and preparation, after the pure magnesium is melted, the Mg-Ni intermediate alloy, pure Al and the Mg-Y intermediate alloy are put together for smelting;

[0029] Step 2: the temperature is increased to 750-800°C, and the alloy is slowly stirred until it is melted, so that it is fully alloyed, and then it is kept for 20-30 min, so as to obtain a magnesium alloy melt;

[0030] Step 3: the magnesium alloy melt obtained in step 2 is pressure cast into an ingot, so as to obtain the Ni-containing magnesium alloy material.

[0031] In some embodiments, since the Al-Y phase is a high-temperature stable phase, the melting temperature has little effect on it; the LPSO phase will appear remelting or precipitation according to different temperatures, so the melting temperature is optimally controlled between 750°C and 800°C, and further preferably between 750°C and 780°C, for example, the melting temperature can be 750°C, 760°C, 770°C, 780°C, etc., and all ranges and sub-ranges between the above-mentioned values; it should be understood that in the embodiments, any of the above-mentioned ranges can be combined with any other range.

[0032] III. Examples and Comparative Examples

[0033] Example 1:

[0034] (1) Ingredients: Select raw materials including various shapes of Ni, Al, Y, and according to the proportion of 5% Ni, 9% Al, 8% Y, and the rest of magnesium, the total weight percentage of the raw materials is greater than 99.5%, and the purity of all raw materials is greater than 99.5%;

[0035] (2) Melting: Put the prepared raw materials into the melting mold and put them into the melting furnace, heat to 750°C, after the raw materials are completely melted, stir evenly and keep warm for 20 min.

[0036] (3) Sampling: Take the material kept warm out of the furnace and slowly put it into water to cool, then take it out of the mold after the material is cooled, and get the magnesium alloy material by extrusion treatment, which is recorded as Mg-Ni-Al-Y material.

[0037] Table 1 (unit: %)

[0038] Examples LPSO phase Al2Y phase Al3Y phase 1 28％ 8％ 5％ 2 14％ 5％ 3％ 3 7％ 3％ 1％ Comparative Example 1 0 0 0 Comparative Example 2 7％ 0 0

[0039] Table 2 (unit: %)

[0040] Examples Ni Al Y Impurities 1 5 9 8 0.1 2 3 6 6 0.1 3 2 3 3 0.1 Comparative Example 1 0 0 0 0.1 Comparative Example 2 3 0 3 0.1

[0041] The magnesium alloy material prepared by the examples and comparative examples was tested for performance, the prepared sample was taken out, clamped on the tiger mouth forceps, the surface oxide layer was polished smooth with a file, and then the powder of the sample material was collected, ensuring that the oxide layer would not enter the collected powder. After checking the sealing of the equipment, 0.25g of sample material powder was taken and put into a three-necked flask, and 30ml of saturated KCl solution was added, and the reaction data was recorded, the longest reaction time was not more than 10min, as shown in Table 3.

[0042] Table 3

[0043]

[0044] From the above examples and comparative examples, it can be seen that the Mg-Ni-Al-Y material prepared by the present application has a faster hydrogen production rate, and the minimum hydrogen production rate at room temperature is 420 ml / min, which is more than 42 times that of pure magnesium and about 3 times that of the pure LPSO phase Mg-Y-Ni alloy. The addition of Al element to the Mg-Y-Ni alloy can promote the formation of Al-Y phase (including Al2Y and Al3Y) between the LPSO phase (see the white bright particles in the figure), which is located in the middle of the LPSO phase. During the hydrolysis process, these Al2Y and Al3Y particles can destroy the continuity of the LPSO phase, and further increase the contact area between the substrate and water during the hydrolysis process. In addition, these particles can also play a role in micro-corrosion, and can form a new hydrolysis mechanism locally, thereby accelerating the hydrolysis rate. Therefore, the magnesium alloy material prepared by the present application has a very high hydrolysis rate and can be used for efficient preparation of hydrogen.

[0045] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the technical solutions. Those of ordinary skill in the art should understand that modifications or equivalent replacements of the technical solutions of the present application without departing from the purpose and scope of the technical solutions should be covered in the scope of the claims of the present application.

Claims

1. A Ni-containing magnesium alloy material capable of rapid hydrolysis to produce hydrogen, characterized in that: The magnesium alloy material contains LPSO phase, Al2Y phase and Al3Y phase; the LPSO phase is composed of Y and Ni; calculated by mass percentage, the magnesium alloy material contains the following components: LPSO phase is 7% to 28%, Al2Y phase is 3% to 8%, Al3Y phase is 1% to 5%, and the balance is magnesium and unavoidable impurity elements.

2. The Ni-containing magnesium alloy material capable of rapid hydrolysis to produce hydrogen according to claim 1, characterized in that: The mass ratio of the Y element to the Ni element is not less than 2.

3. The Ni-containing magnesium alloy material capable of rapid hydrolysis to produce hydrogen according to claim 2, characterized in that: The mass ratio of Al element to Y element is not higher than 1.

4. The Ni-containing magnesium alloy material capable of rapid hydrolysis to produce hydrogen according to any one of claims 1 to 3, characterized in that: Calculated by mass percentage, the magnesium alloy material contains the following components: Ni is 1-5%, Al is 3-9%, and Y is 1-8%.

5. A method for preparing a Ni-containing magnesium alloy material capable of rapid hydrolysis to produce hydrogen, characterized in that: The preparation of the Ni-containing magnesium alloy material according to any one of claims 1 to 4 specifically comprises the following steps: Step 1: Calculate and prepare the materials. After melting pure magnesium, add Mg-Ni master alloy, pure Al and Mg-Y master alloy to smelt together. Step 2: Raise the temperature to 750°C~800°C, slowly stir until the alloy is melted, and after it is fully alloyed, keep it warm and let it stand for 20min~30min to obtain a magnesium alloy melt; Step 3: Die-casting the magnesium alloy melt obtained in step 2 into an ingot to obtain the Ni-containing magnesium alloy material.

6. The method for preparing a Ni-containing magnesium alloy material capable of rapid hydrolysis to generate hydrogen according to claim 5, characterized in that: In step 2, the temperature is raised to 750°C to 780°C.

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