Magnesium alloy material, preparation method, application and magnesium alloy product

Abstract

The present application relates to a magnesium alloy material, its preparation method, application, and magnesium alloy products. The preparation method of the magnesium alloy material comprises the following steps: providing raw materials according to the composition of the magnesium alloy material, wherein the magnesium alloy material comprises the following components by mass percentage: Gd 4% to 8%, Ni 0.05% to 0.2%, Zr 0.1% to 0.5%, and Mg 91.3% to 95.85%; mixing and smelting the raw materials to obtain a melt; casting the melt to obtain a magnesium alloy ingot; and sequentially hot extruding and annealing the magnesium alloy ingot to obtain the magnesium alloy material; the annealing temperature is 350°C to 400°C and the time is 1 hour to 2 hours. The above-mentioned preparation method of the magnesium alloy material effectively improves the elongation after fracture of the magnesium alloy material while ensuring the tensile strength and yield strength of the magnesium alloy material, thereby effectively improving the ductility of the magnesium alloy material.

Description

Technical Field

[0001] The present application relates to the field of alloy technology, and in particular to a magnesium alloy material, a preparation method thereof, applications thereof, and magnesium alloy products. Background Art

[0002] With the development of global industry and the increasing demand for energy, oil and gas extraction has become increasingly important. Oil and gas extraction typically takes place underground, where operations often involve high temperatures and pressures. Traditional downhole tools, such as fracturing sleeves, ball seats, bridge plugs, and seals, are often made of insoluble materials like steel, cast iron, or polymers. These tools must be drilled out after the operation is completed, resulting in long construction times and high costs. Furthermore, the construction process is complex and prone to blockage at depths of several thousand meters.

[0003] Soluble materials can eliminate recycling processes, reduce project risks, and improve construction efficiency. Soluble materials include soluble non-metallic materials and soluble metallic materials. Soluble non-metallic materials include organic polymers and inorganic materials. However, organic polymers and inorganic materials have relatively low mechanical properties and cannot meet the requirements for operation under high temperature and pressure. Traditional soluble metallic materials have better mechanical properties but poor ductility. Summary of the Invention

[0004] Based on this, the present application provides a magnesium alloy material that can have good ductility and suitable solubility while ensuring mechanical properties. In addition, the present application also provides a preparation method, application and magnesium alloy products of the above magnesium alloy material.

[0005] The technical solution of this application to solve the above technical problems is as follows.

[0006] A method for preparing a magnesium alloy material comprises the following steps:

[0007] Providing raw materials according to the composition of the magnesium alloy material, wherein the magnesium alloy material includes the following components by mass percentage: Gd 4% to 8%, Ni 0.05% to 0.2%, Zr 0.1% to 0.5% and Mg 91.3% to 95.85%;

[0008] Mixing and melting the raw materials to obtain a melt;

[0009] Casting the melt to obtain a magnesium alloy ingot;

[0010] The magnesium alloy ingot is subjected to hot extrusion and annealing treatment in sequence to obtain the magnesium alloy material; the annealing treatment temperature is 350° C. to 400° C., and the time is 1 hour to 2 hours.

[0011] In some embodiments, in the method for preparing a magnesium alloy material, the magnesium alloy material includes the following components by mass percentage:

[0012] Gd 4% to 7%, Ni 0.1% to 0.2%, Zr 0.1% to 0.4% and Mg 92.5% to 95.85%.

[0013] In some embodiments, in the method for preparing the magnesium alloy material, the casting step is performed at a temperature of 640°C to 680°C.

[0014] In some embodiments, in the method for preparing the magnesium alloy material, the hot extrusion step is performed at a temperature of 380°C to 400°C.

[0015] In some embodiments, the method for preparing the magnesium alloy material further includes, after the smelting step and before the casting step, a step of refining the melt.

[0016] Accordingly, the present application provides a magnesium alloy material, which is prepared using the above-mentioned method for preparing the magnesium alloy material.

[0017] The present application also provides a magnesium alloy material, which includes the following components, calculated by mass percentage: Gd 4% to 8%, Ni 0.05% to 0.2%, Zr 0.1% to 0.5% and Mg 91.3% to 95.85%; the elongation after fracture of the magnesium alloy material is 29.1% to 40.8%.

[0018] The present application provides the use of the above-mentioned magnesium alloy material in the preparation of magnesium alloy products.

[0019] Accordingly, the present application provides a magnesium alloy product, the raw materials for preparing the magnesium alloy product include the above-mentioned magnesium alloy material.

[0020] In some embodiments, the magnesium alloy article comprises a downhole tool.

[0021] Compared with the prior art, the preparation method of the magnesium alloy material of the present application has the following beneficial effects:

[0022] The preparation method of the above-mentioned magnesium alloy material takes Mg as the base element, supplemented by Gd element to form Mg-Gd alloy, and then supplemented by Ni element to form a second phase with the Mg-Gd alloy, which can promote the dissolution of each alloy element, and the Zr element is melted into the matrix and cooperates with Mg, Gd and Ni elements to play a role in refining the structure; by mixing, melting, casting, hot extruding and annealing the raw materials of specific components in a specific proportion in sequence, and controlling the annealing conditions, on the basis of ensuring the tensile strength and yield strength of the magnesium alloy material, the elongation of the magnesium alloy material is effectively improved, thereby effectively improving the ductility of the magnesium alloy material; and on the basis of ensuring the solubility of the magnesium alloy material, the dissolution rate of the magnesium alloy material is effectively controlled, thereby avoiding the failure of underground operations to be successfully completed due to excessively fast dissolution rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 This is a morphology diagram of the extruded alloy obtained in Example 2;

[0025] Figure 2 is a morphology diagram of the annealed alloy obtained in Example 2;

[0026] Figure 3 This is the SEM morphology of the tensile fracture of the magnesium alloy material obtained in Example 2;

[0027] Figure 4 The dissolution rate curves of the magnesium alloy materials prepared in various embodiments and comparative examples are shown in FIG. DETAILED DESCRIPTION

[0028] The technical solutions of the present application are further described in detail below with reference to specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. It should be understood that the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0031] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the weights described in the examples of this application may be mass units known in the chemical industry, such as μg, mg, g, and kg.

[0032] An embodiment of the present application provides a method for preparing a magnesium alloy material, comprising steps S10 to S40:

[0033] Step S10: providing raw materials according to the composition of the magnesium alloy material, wherein the magnesium alloy material includes the following components by mass percentage: Gd 4% to 8%, Ni 0.05% to 0.2%, Zr 0.1% to 0.5% and Mg 91.3% to 95.85%.

[0034] It can be understood that in the provided raw materials, Gd, Ni, and Zr can be added in the form of alloys, namely gadolinium-based alloys, nickel-based alloys, and zirconium-based alloys; further, the gadolinium-based alloy is a Mg-Gd alloy, the nickel-based alloy is a Mg-Ni alloy, and the zirconium-based alloy is a Mg-Zr alloy, as long as the components in the final magnesium alloy material meet the above ranges; it can also be understood that the mass percentage of the Gd element includes but is not limited to 4%, 4.1%, 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.8%, 7%, 7.2%, 7.5%, 7.8%, and 8%; the mass percentage of the Ni element includes but is not limited to 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.15%, 0.16%, 0.18%, and 0.2%; the mass percentage of the Zr element includes but is not limited to The mass percentage of Ni includes but is not limited to 0.1%, 0.12%, 0.15%, 0.16%, 018%, 0.2%, 0.25%, 0.3%, 0.32%, 0.35%, 0.38%, 0.4%, 0.45%, and 0.5%; the mass percentage of Mg element includes but is not limited to 91.3%, 91.35%, 91.5%, 92%, 92.2%, 92.5%, 92.8%, 93%, 93.2%, 93.5%, 94%, 94.5%, 94.8%, 95%, 95.5%, and 95.85%; it can be further understood that the magnesium alloy material may contain only the four main elements Gd, Ni, Zr and Mg, and when the others are impurity elements, Mg is the remainder element; the magnesium alloy material may also contain non-impurity elements other than the four main elements Gd, Ni, Zr and Mg.

[0035] In some examples, in step S10, the magnesium alloy material includes the following components by mass percentage:

[0036] Gd 4% to 7%, Ni 0.1% to 0.2%, Zr 0.1% to 0.4% and Mg 92.5% to 95.85%.

[0037] In some examples, in step S10, the mass ratio of Zr to Gd in the magnesium alloy material is (0.025-0.1):1.

[0038] It will be appreciated that the mass ratio of Zr to Gd includes, but is not limited to, 0.025:1, 0.03:1, 0.0375:1, 0.05:1, 0.06:1, 0.083:1, 0.09:1, and 0.1:1.

[0039] In some examples, in step S10 , Mg is added in the form of pure magnesium.

[0040] Furthermore, the purity of the pure magnesium is ≥99.95%.

[0041] Step S20: Mix and smelt the raw materials to obtain a melt.

[0042] It can be understood that the smelting is carried out in a smelting furnace; it can be further understood that the raw materials are placed in a crucible in the smelting furnace for smelting.

[0043] In some examples, in step S20 , smelting is performed under a protective gas.

[0044] It is understood that the protective gas includes but is not limited to nitrogen and inert gas.

[0045] Furthermore, the inert gas includes but is not limited to helium and argon.

[0046] In some examples, in step S20 , the smelting temperature is 750° C. to 800° C.

[0047] It can be understood that the melting temperature includes but is not limited to 750°C, 755°C, 760°C, 765°C, 770°C, 775°C, and 800°C.

[0048] In some examples, step S20 includes step S200:

[0049] After pure magnesium is melted, gadolinium-based alloy, nickel-based alloy and zirconium-based alloy are added for smelting.

[0050] In some examples, step S200 further includes a first preheating step of the raw materials and experimental tools before the smelting step.

[0051] Furthermore, the first preheating temperature is 180°C to 200°C.

[0052] It can be understood that the first preheating temperature includes but is not limited to 180°C, 185°C, 190°C, 195°C, and 200°C.

[0053] Furthermore, the first preheating time is not less than 2 hours.

[0054] In some examples, before the step of placing pure magnesium into the crucible in the smelting furnace in step S200 , the step further includes a second preheating step of the crucible.

[0055] Furthermore, the second preheating temperature is 500°C to 700°C.

[0056] In some examples, after the smelting step and before the casting step, a step of refining the melt is further included.

[0057] Optionally, the refining method is selected from at least one of passing argon gas and adding a refining agent.

[0058] Furthermore, the refining agent is C2Cl6.

[0059] In some of the examples, in the refining step, the amount of refining agent used is 2% to 4% by mass of the magnesium alloy material.

[0060] In some of these examples, a slag scraping step is included after the refining step and before the casting step.

[0061] In some of these examples, the mold is preheated to 210° C. to 250° C. prior to the casting step.

[0062] It can be understood that the mold temperature during casting is 190°C to 220°C.

[0063] Step S30: Casting the melt to obtain a magnesium alloy ingot.

[0064] In some examples, in step S30 , the casting step is performed at a temperature of 640° C. to 680° C.

[0065] It will be understood that the casting temperature includes but is not limited to 640°C, 642°C, 644°C, 645°C, 648°C, 650°C, 655°C, 660°C, 665°C, 670°C, 675°C, and 680°C.

[0066] It is understood that the magnesium alloy ingot includes but is not limited to cylindrical bars.

[0067] Step S40: hot extruding and annealing the magnesium alloy ingot in sequence to obtain a magnesium alloy material; the annealing temperature is 350° C. to 400° C., and the time is 1 hour to 2 hours.

[0068] It will be understood that the temperature of the annealing treatment includes but is not limited to 350°C, 355°C, 360°C, 365°C, 370°C, 375°C, 380°C, 385°C, 390°C, 395°C, and 400°C, and the time includes but is not limited to 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.8h, and 2h.

[0069] In some examples, in step S40 , the hot extrusion step is performed at a temperature of 380° C. to 400° C.

[0070] It can be understood that the temperature of hot extrusion includes but is not limited to 380°C, 385°C, 390°C, 395°C, and 400°C.

[0071] The preparation method of the above-mentioned magnesium alloy material takes Mg as the basic element, supplemented by Gd element to form Mg-Gd alloy, and then supplemented by Ni element to form a second phase with the Mg-Gd alloy, which can promote the dissolution of each alloy element, and the Zr element is melted into the matrix and cooperates with Mg, Gd and Ni elements to play a role in refining the structure; by sequentially mixing, smelting, casting, hot extruding and annealing the raw materials of specific components, and controlling the annealing conditions, on the basis of ensuring the tensile strength and yield strength of the magnesium alloy material, the elongation of the magnesium alloy material is effectively improved, thereby effectively improving the ductility of the magnesium alloy material; and on the basis of ensuring the solubility of the magnesium alloy material, the dissolution rate of the magnesium alloy material is effectively controlled, thereby avoiding the failure of underground operations to be successfully completed due to excessively fast dissolution rate.

[0072] The preparation method of the above magnesium alloy material has simple production process, high safety and reliability, and the elongation after fracture of the prepared magnesium alloy material is above 20%, even up to 40.8%; and the tensile strength is above 202R m / MPa and above, the yield strength is 106R p0.2 / MPa or above, and the dissolution rate is appropriate; it is suitable for working conditions of 80℃~150℃.

[0073] One embodiment of the present application provides a magnesium alloy material, which is prepared using the above-mentioned method for preparing the magnesium alloy material.

[0074] Another embodiment of the present application provides a magnesium alloy material, which includes the following components, calculated by mass percentage: Gd 4% to 8%, Ni 0.05% to 0.2%, Zr 0.1% to 0.5% and Mg 91.3% to 95.85%; the elongation after fracture of the magnesium alloy material is 20.2% to 40.8%.

[0075] Optionally, the elongation after fracture of the magnesium alloy material is 24.6% to 40.8%; further, the elongation after fracture of the magnesium alloy material is 29.1% to 40.8%; further, the elongation after fracture of the magnesium alloy material is 35% to 40.8%.

[0076] In some examples, the solubility of magnesium alloy materials at 93℃ / 3% KCl is 3.26 mg / cm 2 / h~4.38mg / cm 2 / h.

[0077] It is understood that the dissolution rate of magnesium alloy materials under 93°C / 3% KCl conditions includes but is not limited to 3.26 mg / cm 2 / h, 3.66mg / cm 2 / h, 3.7mg / cm 2 / h, 3.73mg / cm 2 / h, 3.81mg / cm 2 / h, 4mg / cm 2 / h, 4.38mg / cm 2 / h.

[0078] It can be understood that the magnesium alloy material includes the following components, calculated by mass percentage: Gd 4% to 8%, Ni 0.05% to 0.2%, Zr 0.1% to 0.5% and Mg 91.3% to 95.85%.

[0079] It can also be understood that the magnesium alloy material provided in this application has tensile strength and yield strength that can meet the use requirements of downhole fracturing sliding sleeve ball seats, bridge plugs, sealing rings and other operating tool components, and has good ductility.

[0080] One embodiment of the present application provides the use of the above-mentioned magnesium alloy material in the preparation of a magnesium alloy product. Another embodiment of the present application provides a magnesium alloy product, the raw materials for the preparation of which include the above-mentioned magnesium alloy material.

[0081] The above-mentioned magnesium alloy material is used to prepare magnesium alloy products, which can give the magnesium alloy products good ductility.

[0082] In some embodiments, the magnesium alloy article includes, but is not limited to, a downhole tool.

[0083] Furthermore, downhole operation tools include but are not limited to downhole fracturing sleeve ball seats, bridge plugs, and sealing rings.

[0084] In some embodiments, the raw materials for preparing the magnesium alloy product may be the aforementioned magnesium alloy materials, that is, the magnesium alloy product may be directly prepared using the aforementioned magnesium alloy materials. In other embodiments, the raw materials for preparing the magnesium alloy product may include other materials in addition to the aforementioned magnesium alloy materials.

[0085] The following examples are given according to the magnesium alloy material and its preparation method, application and magnesium alloy products of the present application. It can be understood that the magnesium alloy material and its preparation method, application and magnesium alloy products of the present application are not limited to the following embodiments.

[0086] Example 1

[0087] (1) Prepare raw materials of pure magnesium, Mg-Gd alloy, Mg-Ni alloy, and Mg-Zr alloy according to the composition of magnesium alloy materials. The composition and its mass percentage are Mg-4Gd-0.15Ni-0.1Zr (in the magnesium alloy material, the mass percentage of Gd is 4%, the mass percentage of Ni is 0.15%, the mass percentage of Zr is 0.1%, and the balance is Mg and unavoidable impurities; wherein, the mass ratio of Zr to Gd is 0.025:1); put the prepared raw materials, molds and other experimental tools into a baking oven for preheating at a temperature of 180°C for 2 hours;

[0088] (2) Set the resistance furnace temperature to 500°C and place the crucible in the furnace. When the crucible reaches 500°C, add pure magnesium, pass protective gas, and raise the temperature to 760°C. After the magnesium is completely melted, add Mg-Gd alloy, keep warm for 10 minutes, stir for 2 minutes, and then keep warm for 30 minutes. When the temperature rises to 780°C, add Mg-Ni alloy and Mg-Zr alloy, keep warm for 10 minutes, stir for 2 minutes, and then keep warm for 30 minutes.

[0089] (3) The temperature was lowered to 700°C, a C2Cl6 refining agent was added, and the mixture was allowed to stand for 5 minutes for refining. The slag was then scraped off and the mixture was allowed to stand for another 10 minutes. The temperature was then set to 650°C. When the melt temperature reached 650°C, the mixture was cast into a mold preheated to 220°C to obtain a magnesium alloy ingot.

[0090] (4) hot extruding the magnesium alloy ingot at 400° C. to obtain an extruded rod;

[0091] (5) The extruded rod is annealed at 400°C for 2 hours to obtain a magnesium alloy material.

[0092] Example 2

[0093] The method is basically the same as Example 1, except that the mass percentages of the components of the magnesium alloy material are different, as follows:

[0094] (1) Prepare raw materials of pure magnesium, Mg-Gd alloy, Mg-Ni alloy, and Mg-Zr alloy according to the composition of magnesium alloy materials. The composition and its mass percentage are Mg-6Gd-0.15Ni-0.5Zr (in the magnesium alloy material, the mass percentage of Gd is 6%, the mass percentage of Ni is 0.15%, the mass percentage of Zr is 0.5%, and the balance is Mg and unavoidable impurities); wherein the mass ratio of Zr to Gd is 0.083:1); place the prepared raw materials, molds and other experimental tools in a baking oven for preheating at a temperature of 180°C for 2 hours;

[0095] (2) Set the resistance furnace temperature to 500°C and place the crucible in the furnace. When the crucible reaches 500°C, add pure magnesium, pass protective gas, and raise the temperature to 760°C. After the magnesium is completely melted, add Mg-Gd alloy, keep warm for 10 minutes, stir for 2 minutes, and then keep warm for 30 minutes. When the temperature rises to 780°C, add Mg-Ni alloy and Mg-Zr alloy, keep warm for 10 minutes, stir for 2 minutes, and then keep warm for 30 minutes.

[0096] (3) The temperature was lowered to 700°C, a C2Cl6 refining agent was added, and the mixture was allowed to stand for 5 minutes for refining. The slag was then scraped off and the mixture was allowed to stand for another 10 minutes. The temperature was then set to 650°C. When the melt temperature reached 650°C, the mixture was cast into a mold preheated to 220°C to obtain a magnesium alloy ingot.

[0097] (4) The magnesium alloy ingot is hot extruded at 400°C to obtain an extruded rod; the morphology of the extruded alloy is as follows: Figure 1 As shown;

[0098] (5) The extruded rod is annealed at 400°C for 2 hours to obtain a magnesium alloy material; the morphology of the annealed alloy is as follows Figure 2 As shown, the SEM morphology of the tensile fracture is as follows Figure 3 shown.

[0099] from Figure 1 It can be seen that the alloy microstructure is uniform, a large number of irregularly shaped second phase structures are distributed at the grain boundaries, and alloy element enriched particles exist locally; Figure 2 It can be seen that the fine needle-like phase in the alloy disappears and transforms into a large number of short plate-like second phases, which also contain a small amount of blocky Mg-Gd phase. Figure 3 It can be seen that there are tearing edges and many dimples at the fracture surface under room temperature tension, which can improve the elongation of magnesium alloy materials. The cracks extend along the grain boundaries and the fracture mode is quasi-cleavage fracture.

[0100] Example 3

[0101] It is basically the same as Example 1, except that the mass percentages of the components of the magnesium alloy material are different, namely Mg-8Gd-0.15Ni-0.3Zr (in the magnesium alloy material, the mass percentage of Gd is 8%, the mass percentage of Ni is 0.15%, the mass percentage of Zr is 0.3%, and the balance is Mg and unavoidable impurities); wherein the mass ratio of Zr to Gd is 0.0375:1.

[0102] Example 4

[0103] The method is basically the same as Example 2, except that, in step (5), the annealing temperature is 350° C. and the annealing time is 2 h. The specific steps of step (5) are as follows:

[0104] (5) The extruded rod is annealed at 350°C for 2 hours to obtain a magnesium alloy material.

[0105] Example 5

[0106] The method is basically the same as Example 2, except that, in step (5), the annealing temperature is 380° C. and the time is 1 h. The specific steps of step (5) are as follows:

[0107] (5) The extruded rod was annealed at 380°C for 1 hour to obtain a magnesium alloy material.

[0108] Example 6

[0109] (1) Prepare raw materials of pure magnesium, Mg-Gd alloy, Mg-Ni alloy, and Mg-Zr alloy according to the composition of magnesium alloy materials. The composition and its mass percentage are Mg-6Gd-0.05Ni-0.5Zr (in the magnesium alloy material, the mass percentage of Gd is 6%, the mass percentage of Ni is 0.05%, the mass percentage of Zr is 0.5%, and the balance is Mg and unavoidable impurities); put the prepared raw materials, molds and other experimental tools into a baking oven for preheating at a temperature of 180°C for 2 hours;

[0110] (2) Set the resistance furnace temperature to 500°C and place the crucible in the furnace. When the crucible reaches 500°C, add pure magnesium, pass protective gas, and raise the temperature to 760°C. After the magnesium is completely melted, add Mg-Gd alloy, keep warm for 10 minutes, stir for 2 minutes, and then keep warm for 30 minutes. When the temperature rises to 780°C, add Mg-Ni alloy and Mg-Zr alloy, keep warm for 10 minutes, stir for 2 minutes, and then keep warm for 30 minutes.

[0111] (3) The temperature was lowered to 700°C, a C2Cl6 refining agent was added, and the mixture was allowed to stand for 5 minutes for refining. The slag was then scraped off and the mixture was allowed to stand for another 10 minutes. The temperature was then set to 680°C. When the melt temperature reached 680°C, the mixture was cast into a mold preheated to 220°C to obtain a magnesium alloy ingot.

[0112] (4) hot extruding the magnesium alloy ingot at 380° C. to obtain an extruded rod;

[0113] (5) The extruded rod is annealed at 400°C for 2 hours to obtain a magnesium alloy material.

[0114] Comparative Example 1

[0115] (1) Prepare raw materials of pure magnesium, Mg-Gd alloy, Mg-Ni alloy, and Mg-Zr alloy according to the composition of magnesium alloy materials, and the composition and mass percentage are Mg-6Gd-0.15Ni-0.5Zr; put the prepared raw materials, molds and other experimental tools into a baking oven for preheating at a temperature of 180°C for 2 hours;

[0116] (2) Set the resistance furnace temperature to 500°C and place the crucible in the furnace. When the crucible reaches 500°C, add pure magnesium, pass protective gas, and raise the temperature to 760°C. After the magnesium is completely melted, add Mg-Gd alloy, keep warm for 10 minutes, stir for 2 minutes, and then keep warm for 30 minutes. When the temperature rises to 780°C, add Mg-Ni alloy and Mg-Zr alloy, keep warm for 10 minutes, stir for 2 minutes, and then keep warm for 30 minutes.

[0117] (3) The temperature was lowered to 700°C, a C2Cl6 refining agent was added, and the mixture was allowed to stand for 5 minutes for refining. The slag was then scraped off and the mixture was allowed to stand for another 10 minutes. The temperature was then set to 650°C. When the melt temperature reached 650°C, the mixture was cast into a mold preheated to 220°C to obtain a magnesium alloy ingot.

[0118] (4) The magnesium alloy ingot is hot extruded at 400°C and then naturally cooled to obtain a magnesium alloy material.

[0119] Comparative Example 2

[0120] The method is basically the same as Example 2, except that, in step (5), the annealing temperature is 200° C. and the annealing time is 12 h. The specific steps of step (5) are as follows:

[0121] (5) The extruded rod was aged at 200°C for 12 hours to obtain a magnesium alloy material.

[0122] Comparative Example 3

[0123] The method is basically the same as Example 2, except that, in step (5), the annealing temperature is 200° C. and the annealing time is 24 h. The specific steps of step (5) are as follows:

[0124] (5) The extruded rod is aged at 200°C for 24 hours to obtain a magnesium alloy material.

[0125] Comparative Example 4

[0126] It is basically the same as Example 2, except that the Zr element is replaced by an equal amount of Zn element, and the magnesium alloy material is Mg-6Gd-0.15Ni-0.5Zn (in the magnesium alloy material, the mass percentage of Gd is 6%, the mass percentage of Ni is 0.15%, the mass percentage of Zn is 0.5%, and the balance is Mg and unavoidable impurities).

[0127] Comparative Example 5

[0128] It is basically the same as Example 2, except that the Zr element is replaced by an equal amount of Mn element, and the magnesium alloy material is Mg-6Gd-0.5Mn-0.15Ni (in the magnesium alloy material, the mass percentage of Gd is 6%, the mass percentage of Ni is 0.15%, the mass percentage of Mn is 0.5%, and the balance is Mg and unavoidable impurities).

[0129] Comparative Example 6

[0130] It is basically the same as Example 2, except that the Gd element is replaced by an equal amount of Y element, and the magnesium alloy material is Mg-6Y-0.15Ni-0.5Zr (in the magnesium alloy material, the mass percentage of Y is 6%, the mass percentage of Ni is 0.15%, the mass percentage of Zr is 0.5%, and the balance is Mg and unavoidable impurities).

[0131] Comparative Example 7

[0132] It is basically the same as Example 2, except that the Ni element is replaced by an equal amount of Cu element, and the magnesium alloy material is Mg-6Gd-0.15Cu-0.5Zr (in the magnesium alloy material, the mass percentage of Gd is 6%, the mass percentage of Cu is 0.15%, the mass percentage of Zr is 0.5%, and the balance is Mg and unavoidable impurities).

[0133] Comparative Example 8

[0134] It is basically the same as Example 2, except that the mass percentages of the components of the magnesium alloy material are different, namely Mg-3Gd-3.15Ni-0.5Zr (in the magnesium alloy material, the mass percentage of Gd is 3%, the mass percentage of Ni is 3.15%, the mass percentage of Zr is 0.5%, and the balance is Mg and unavoidable impurities).

[0135] The magnesium alloy materials prepared in each embodiment and comparative example were subjected to performance tests according to the test standard GB / T228.1-2021; the dissolution rate test conditions were 93°C / 3% KCl; the test results are shown in Table 1, and the dissolution rate curve is shown in Figure 4 As shown, the horizontal axis is the dissolution time, and the vertical axis is the mass fraction of the magnesium alloy material remaining after dissolution for different times.

[0136] Table 1

[0137]

[0138]

[0139] As shown in Table 1, the tensile strength of the magnesium alloy materials prepared in the examples is higher than that in the comparative examples. m / MPa and above, the yield strength is 116R p0.2 / MPa or above, the elongation after break is 29.1% to 40.8%, and the dissolution rate under 93℃ / 3% KCl is 3.7mg / cm 2 / h~4.38mg / cm 2 / h, the dissolution rate is appropriate, and dissolution before the underground operation is successfully completed due to the excessive dissolution rate is avoided. In Comparative Example 1, no annealing treatment is performed after hot extrusion, and in Comparative Examples 2-3, the extruded rods are not annealed but aged. The elongation after fracture of the obtained magnesium alloy materials decreases to varying degrees, and the dissolution rate is relatively fast, which easily leads to the failure of the underground operation to be successfully completed due to the excessive dissolution rate. In Comparative Examples 4-6, the Zr element is replaced by an equal amount of Zn element or Mn element, and the Gd element is replaced by an equal amount of Y element. The elongation after fracture of the magnesium alloy material obtained in Comparative Example 4 is significantly reduced, the tensile strength of the magnesium alloy material obtained in Comparative Example 5 is lower than 200 MPa, and the dissolution performance of the magnesium alloy material obtained in Comparative Example 6 is poor.

[0140] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0141] The embodiments described above only express several implementation methods of the present application, which are convenient for understanding the technical solutions of the present application in a specific and detailed manner, but they cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all fall within the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description and drawings can be used to interpret the content of the claims.

Claims

1. A method for preparing a magnesium alloy material, characterized in that: The following steps are involved: Providing raw materials according to the composition of the magnesium alloy material, wherein the magnesium alloy material includes the following components by mass percentage: Gd 4%-7%, Ni 0.1%-0.2%, Zr 0.1%-0.5% and Mg 92.5%-95.5%; Mixing and melting the raw materials to obtain a melt; Casting the melt to obtain a magnesium alloy ingot; The magnesium alloy ingot is sequentially subjected to hot extrusion and annealing treatment to obtain the magnesium alloy material; the hot extrusion step is performed at a temperature of 380° C. to 400° C.; the annealing treatment temperature is 390° C. to 400° C. and the time is 1 h to 2 h; The dissolution rate of the magnesium alloy material under 93℃ / 3% KCl conditions is 3.7 mg / cm 2 / h~4.38 mg / cm 2 / h.

2. The method for preparing a magnesium alloy material according to claim 1, wherein: The magnesium alloy material comprises the following components by mass percentage: Gd 4%~6%, Ni 0.15%~0.2%, Zr 0.1%~0.4% and Mg 93.5%~95.5%.

3. The method for preparing a magnesium alloy material according to any one of claims 1 to 2, characterized in that: The casting step is performed at a temperature of 640°C to 680°C.

4. The method for preparing a magnesium alloy material according to any one of claims 1 to 2, wherein: After the smelting step and before the casting step, the method further includes a step of refining the melt.

5. A magnesium alloy material, characterized in that: The magnesium alloy is prepared by the method for preparing the magnesium alloy according to any one of claims 1 to 4.

6. Use of the magnesium alloy material according to claim 5 in the preparation of magnesium alloy products.

7. A magnesium alloy product, characterized in that: The raw materials for its preparation include the magnesium alloy material as claimed in claim 5.

8. The magnesium alloy product according to claim 7, wherein: The magnesium alloy product includes a downhole operation tool.

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