High-temperature controllable dissolution rate aluminum alloy and preparation method thereof

Abstract

The invention relates to the technical field of aluminum alloys, in particular to a high-temperature controllable dissolution rate aluminum alloy and a preparation method thereof, and the aluminum alloy comprises the following elements in percentage by weight: 0.1-1.5% of Ga, 0.5-2.0% of In, 0.5-2.0% of Sn, 0.1-5.0% of Mg, 0.1-4.0% of Zn, 0.1-1.5% of Cu, 0.01-0.3% of Zr, 0.01-0.3% of Ti and the balance of Al and inevitable impurity elements. The preparation method has the advantages that the soluble aluminum alloys with different dissolution rates are prepared by regulating and controlling the proportion and the addition amount of alloy elements, and the soluble aluminum alloys with different properties can be obtained by carrying out heat treatment or aging treatment on cast ingots of all the components subsequently; according to the soluble aluminum alloy prepared through the method, the dissolution rate can be regulated and controlled in a high-temperature environment, the process is simple, and the production cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloys, in particular to a high-temperature dissolution rate controllable aluminum alloy and a preparation method thereof. Background Art

[0002] Soluble aluminum alloys hold broad application prospects in oil and gas exploration and development. With the continuous exploitation of oil and gas resources, drilling operations in complex geological conditions face numerous challenges. Soluble aluminum alloys can be used to manufacture temporary downhole tools, such as dissolvable fracturing balls and bridge plugs.

[0003] In traditional fracturing operations, the steel fracturing balls and bridge plugs used require complex subsequent operations such as drilling and grinding to remove after the fracturing task is completed. This is not only time-consuming and labor-intensive, but also increases operational costs and risks. Soluble aluminum alloy fracturing balls and bridge plugs, however, gradually dissolve in specific downhole environments, such as formation water at a certain temperature and pressure, eliminating the need for drilling and grinding operations. This significantly improves operational efficiency and reduces costs. Furthermore, the use of soluble aluminum alloy tools reduces damage to the formation, helping to protect oil and gas reservoirs and increase oil and gas recovery rates. For example, in fracturing operations in some deep shale gas wells, soluble aluminum alloy fracturing balls can quickly dissolve after the fracturing task is completed, providing a smooth channel for subsequent oil and gas production.

[0004] In recent years, research literature on soluble aluminum alloys has shown that the solubility of aluminum alloys mainly depends on low-melting-point alloys of Ga, In, and Sn. These metals are expensive and will greatly increase the investment cost of soluble aluminum alloys. Therefore, it is imperative to consider other elements to replace some low-melting-point alloys to reduce the preparation cost of soluble aluminum alloys. According to existing literature, the addition of Zn elements can effectively regulate the degradation rate of alloys and expand the operating temperature range of degradable materials. If Zn is used to replace some low-melting-point alloys, aluminum alloy materials with a certain dissolution effect can be obtained. The appropriate addition of conventional alloying elements such as Mg and Cu and heat treatment of soluble aluminum alloys can regulate the dissolution rate and mechanical properties of soluble aluminum alloys. Therefore, replacing expensive low-melting-point metals with conventional elements will hopefully reduce the cost of soluble aluminum alloy materials and promote market applications. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a high-temperature controllable dissolution rate aluminum alloy and a preparation method thereof. By regulating different alloying elements, the proportion of low-melting-point alloys is reduced, ensuring that the aluminum alloy has an appropriate dissolution effect while reducing costs. By subsequent heat treatment, the dissolution rate and strength of the soluble aluminum alloy are regulated, effectively solving the shortcomings of the prior art.

[0006] In order to achieve the above-mentioned object, the present invention provides a high-temperature controllable dissolution rate aluminum alloy, which includes the following components in mass percentage: Ga0.1-1.5%, In0.5-2.0%, Sn0.5-2.0%, Mg0.1-5.0%, Zn0.1-4.0%, Cu0.1-1.5%, Zr0.01-0.3%, Ti0.01-0.3% and the remaining component Al.

[0007] In order to achieve the above object, the present invention also provides a method for preparing a high-temperature aluminum alloy with a controllable dissolution rate, which is used to prepare the above aluminum alloy, comprising the following steps:

[0008] S1. Alloy smelting:

[0009] 1.1 Pretreatment: Grind the weighed alloy raw materials to remove the surface oxide layer and preheat them in a drying oven at 200℃;

[0010] 1.2 Melting: Place pure aluminum in a corundum crucible and heat to 720℃ to melt. After passing inert gas, heat to 740-760℃ and keep warm for 30 minutes.

[0011] 1.3 Alloying: Add the remaining alloy raw materials in sequence, stir and keep the temperature at 740-760℃ for 20 minutes;

[0012] 1.4 Refining treatment: Add special refining agent for aluminum alloy, stir evenly at 740-760℃, degas and let it stand;

[0013] 1.5 Casting: The melt is cooled to 720℃, refined by adding refiner for modification, and then cast into ingots;

[0014] S2. Heat treatment:

[0015] 2.1 Solution treatment: keep the ingot at 390-500℃ for 4-24 hours;

[0016] 2.2 Aging treatment: After solution treatment, the material is aged at 160-200℃ for 8-24 hours.

[0017] Preferably, any of the above schemes is that the Ga, In, Sn, Mg and Zn are added in the form of pure metals tightly wrapped in aluminum foil, and the Cu, Zr and Ti are added in the form of aluminum master alloy.

[0018] Preferably, in any of the above schemes, the inert gas introduced in step S1 is argon, and the refining agent is Al-Ti5-B1.

[0019] Preferably, any of the above schemes is that the melt composition is tested before casting in step S1, and casting can be carried out only after the alloy composition is qualified.

[0020] Preferably, in any of the above schemes, after the molten cast base material is placed in the resistance furnace in step S2, the temperature is raised from room temperature to a set temperature or the base material is directly placed in the resistance furnace at the set temperature.

[0021] Preferably, any of the above schemes is that the dissolution rate of the soluble aluminum alloy materials with different compositions and heat treatment states is 4 to 400 mg / (h*cm2) under the dissolution conditions of 90°C / 3% KCl.

[0022] Preferably, any of the above solutions has a tensile strength of 130 MPa to 220 MPa after solution treatment and aging treatment.

[0023] The present invention has the following advantages:

[0024] 1. This high-temperature controllable dissolution rate aluminum alloy and its preparation method, by regulating the alloy composition and subsequent heat treatment process, can obtain soluble materials with different dissolution rates and different strengths to meet the degradation rate requirements of different downhole soluble components such as soluble fracturing balls and bridge plugs.

[0025] 2. The high-temperature controllable dissolution rate aluminum alloy and its preparation method can reduce the amount of low-melting-point metal added to the soluble aluminum alloy through component design, thereby reducing production costs.

[0026] 3. The high-temperature controllable dissolution rate aluminum alloy and its preparation method provide a high-temperature dissolvable soluble aluminum alloy with a simple process and easy production, and the addition of alloying elements to the soluble aluminum alloy is more environmentally friendly. DETAILED DESCRIPTION

[0027] The present invention is further described below, but the protection scope of the present invention is not limited to the following description.

[0028] Example 1: A high-temperature controllable dissolution rate aluminum alloy, which includes the following components in mass percentage: Ga1.1%, In1.4%, Sn0.7%, Mg0.8%, Zn1.1%, Cu0.8%, Zr0.16%, Ti0.12%, and the rest are Al and unavoidable impurity elements.

[0029] A method for preparing a high-temperature, controllable dissolution rate aluminum alloy comprises the following steps:

[0030] The alloy raw materials weighed in proportion are polished to remove the surface oxide layer, and then placed in a drying oven at 200°C for drying and preheating; the dried pure aluminum is placed in a corundum crucible and heated to melt, the temperature is set to 720°C, and after the pure aluminum is melted, the melt temperature is raised to 740-760°C and kept warm for 30 minutes; while maintaining the temperature, Ga, In, Sn, Mg and Zn are all added in the form of pure metals wrapped tightly with aluminum foil, and Cu, Zr and Ti are all added in sequence in the form of aluminum master alloys, the melt is stirred and kept warm for 20 minutes; the aluminum alloy melt temperature is controlled at 740-760°C, uniformly stirred, and a special aluminum alloy refining agent is added for refining treatment; after refining, a degassing device is used to degas the melt, and after the melt is allowed to stand, the melt temperature is lowered to 720°C for casting, and a refiner is added for modification before casting, and the desired ingot is obtained after casting.

[0031] The alloy dissolution rate was further tested by cutting the smelted ingot into Then, use 240#-4000# sandpaper to coarsely and finely grind the surface of the disc sample until the sample surface is smooth and free of defects; use acetone and anhydrous ethanol to perform ultrasonic oscillation cleaning in turn to remove impurities and residual acetone on the surface of the sample; finally, use a hair dryer with cold air to quickly dry it and wrap it in plastic wrap for use to avoid re-contamination. Before the test began, the initial mass of the sample was recorded using an electronic balance with a 0.1 mg scale. The initial sample surface area was recorded using a vernier caliper. A 3% KCl solution was prepared in a constant-temperature water bath according to laboratory equipment and maintained at 90°C. A rotor was placed at the bottom of the water bath to maintain constant water flow. Samples were removed at regular intervals. According to the GB / T16545-2015 standard, "Removal of Corrosion Products from Metal and Alloy Corrosion Specimens," the dissolved sample was rinsed in a 1.42 g / mL HNO3 solution for 2 minutes to remove dissolved products from the sample surface. The sample surface was then rinsed with anhydrous ethanol and dried with an air conditioner. Finally, the remaining sample mass was weighed and recorded, and the dissolution rate was calculated using the subsequent formula. To ensure experimental accuracy, three identical samples were selected for the test, with samples taken at equal intervals until dissolved. The average value was used as the dissolution rate test result.

[0032]

[0033] V represents the dissolution rate of the material (mg / (h*cm2)), M represents the initial mass of the sample (mg), Mt represents the mass of the sample after immersion for t hours and removal of surface dissolved products (mg), S represents the initial surface area of ​​the dissolved specimen immersed in the solution (cm2), and T represents the dissolution time (h).

[0034] Example 2

[0035] Different from the above-mentioned Example 1, the contents of Mg and Sn are increased on the basis of Example 1, and the metals are weighed according to a certain component ratio. The mass fractions of the metals are: Ga 1.0%, In 1.4%, Sn 1.1%, Mg 1.3%, Zn 1.1%, Cu 0.7%, Zr 0.18%, Ti 0.13%, and the rest are Al and unavoidable impurity elements.

[0036] Example 3

[0037] Different from the above-mentioned Example 1, the contents of Mg and Sn are increased on the basis of Example 1, and the metals are weighed according to a certain component ratio. The mass fractions of the metals are: Ga 1.0%, In 1.4%, Sn 1.4%, Mg 1.8%, Zn 1.1%, Cu 0.7%, Zr 0.12%, Ti 0.11%, and the rest are Al and unavoidable impurity elements.

[0038] Example 4

[0039] Different from the above-mentioned Example 1, the contents of Mg and Sn are increased on the basis of Example 1, and the metals are weighed according to a certain component ratio. The mass fractions of the metals are: Ga 1.0%, In 1.4%, Sn 1.7%, Mg 2.2%, Zn 1.1%, Cu 0.7%, Zr 0.08%, Ti 0.09%, and the rest are Al and unavoidable impurity elements.

[0040] Example 5

[0041] Different from the above-mentioned Example 1, the contents of Mg, Zn, Cu and Sn are changed on the basis of Example 1, and each metal is weighed according to a certain component ratio. The mass fractions of each metal are: Ga 1.0%, In 1.4%, Sn 1.5%, Mg 3.8%, Zn 2.3%, Cu 0.9%, Zr 0.08%, Ti 0.09%, and the rest are Al and unavoidable impurity elements.

[0042] Comparative Example 1

[0043] The ingot in Example 1 was subjected to subsequent heat treatment. Specifically, the ingot was placed in a resistance furnace and heated from room temperature to a holding temperature, or directly placed in a resistance furnace at a set temperature. Solution treatment was performed at a holding temperature of 460°C for 6 hours, followed by air cooling to room temperature to obtain a solid solution soluble aluminum alloy.

[0044] Comparative Example 1-1

[0045] The soluble material in Comparative Example 1 was placed in a resistance furnace and subjected to aging treatment as the furnace temperature increased. The aging temperature was 170° C. and the aging time was 12 h. The alloy was then air-cooled to room temperature to obtain an aged soluble aluminum alloy.

[0046] Comparative Example 2

[0047] Example 2 was subjected to subsequent heat treatment. Specifically, the ingot was placed in a resistance furnace and heated from room temperature to a holding temperature, or directly placed in a resistance furnace at a set temperature. Solution treatment was performed at a holding temperature of 460°C for 6 hours, followed by air cooling to room temperature to obtain a solid solution soluble aluminum alloy.

[0048] Comparative Example 2-1

[0049] The soluble material in Comparative Example 2 was placed in a resistance furnace and subjected to aging treatment as the furnace temperature increased. The aging temperature was 170° C. and the aging time was 12 h. The alloy was then air-cooled to room temperature to obtain an aged soluble aluminum alloy.

[0050] Comparative Example 3

[0051] Example 3 was subjected to subsequent heat treatment. The specific heat treatment method was as follows: after placing the ingot in a resistance furnace, the temperature was raised from room temperature to a holding temperature; or the ingot was directly placed in a resistance furnace at a set temperature. A solution treatment was performed at a holding temperature of 460°C for 6 hours, followed by air cooling to room temperature to obtain a solid solution soluble aluminum alloy.

[0052] Comparative Example 3-1

[0053] The soluble material in Comparative Example 3 was placed in a resistance furnace and subjected to aging treatment as the furnace temperature increased. The aging temperature was 170° C. and the aging time was 12 h. The alloy was then air-cooled to room temperature to obtain an aged soluble aluminum alloy.

[0054] Comparative Example 4

[0055] Example 4 was subjected to subsequent heat treatment. Specifically, the ingot was placed in a resistance furnace and heated from room temperature to a holding temperature, or directly placed in a resistance furnace at a set temperature. Solution treatment was performed at a holding temperature of 460°C for 6 hours, followed by air cooling to room temperature to obtain a solid solution soluble aluminum alloy.

[0056] Comparative Example 4-1

[0057] The soluble material in Comparative Example 4 was placed in a resistance furnace and subjected to aging treatment as the furnace temperature increased. The aging temperature was 170° C. and the aging time was 12 h. The soluble material was then air-cooled to room temperature to obtain an aged soluble aluminum alloy.

[0058] Comparative Example 5

[0059] Example 5 was subjected to subsequent heat treatment. Specifically, the ingot was placed in a resistance furnace and heated from room temperature to a holding temperature, or directly placed in a resistance furnace at a set temperature. Solution treatment was performed at a holding temperature of 460°C for 6 hours, followed by air cooling to room temperature to obtain a solid solution soluble aluminum alloy.

[0060] Comparative Example 5-1

[0061] The soluble material in Comparative Example 5 was placed in a resistance furnace and subjected to aging treatment as the furnace temperature increased. The aging temperature was 170° C. and the aging time was 12 h. The alloy was then air-cooled to room temperature to obtain an aged soluble aluminum alloy.

[0062] Table 1 Test results of solubility and hardness of cast soluble aluminum alloy

[0063]

[0064]

[0065] Table 2 Test results of solubility properties of solid solution soluble aluminum alloy

[0066]

[0067] Table 3 Test results of solubility and mechanical properties of aged soluble aluminum alloy

[0068]

[0069]

[0070] In summary, the high-temperature controllable dissolution rate aluminum alloy and its preparation method of the present invention, by adding low-melting point Ga, In and Sn elements, changing the ratio of In and Sn to control the proportion of In3Sn and InSn4 phases, preliminarily regulate the dissolution rate of the cast alloys of Examples 1 to 5, and adding conventional elements Mg, Cu, and Zn to adjust the structure of the soluble aluminum alloys of Examples 1 to 5, adding Ti and Zr to refine the grains and increase the dissolution rate of the alloy, and preparing five soluble aluminum alloys with different compositions to obtain materials with different dissolution rates.

[0071] The present invention performs subsequent heat treatment on the soluble alloy, which can not only further improve the mechanical properties of the alloy, including hardness and tensile properties, but also regulate the dissolution rate.

[0072] The soluble aluminum alloy materials prepared by the present invention have controllable dissolution rates and good mechanical properties. Under the dissolution conditions of 90°C / 3% KCl, the dissolution rate is 4 to 400 mg / (h*cm²). The tensile strength of the soluble aluminum alloy after solution treatment and aging treatment is 130 MPa to 220 MPa.

[0073] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-temperature controllable dissolution rate aluminum alloy, characterized by: The composition includes the following components in mass percentage: Ga0.1-1.5%, In0.5-2.0%, Sn0.5-2.0%, Mg0.1-5.0%, Zn0.1-4.0%, Cu0.1-1.5%, Zr0.01-0.3%, Ti0.01-0.3% and the remaining component Al.

2. The high-temperature controlled dissolution rate aluminum alloy according to claim 1, characterized in that: The composition includes the following components in mass percentage: Ga 0.5-1.5%, In 1.0-2.0%, Sn 0.5-2.0%, Mg 0.5-4.0%, Zn 0-3.0%, Cu 0.5-1.0%, Zr 0.01-0.2%, Ti 0.01-0.2% and the remaining component Al.

3. A method for preparing a high-temperature, controllable dissolution rate aluminum alloy, for preparing the aluminum alloy according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1. Alloy smelting: 1.1 Pretreatment: Grind the weighed alloy raw materials to remove the surface oxide layer and preheat them in a drying oven at 200℃; 1.2 Melting: Place pure aluminum in a corundum crucible and heat to 720℃ to melt. After passing inert gas, heat to 740-760℃ and keep warm for 30 minutes. 1.3 Alloying: Add the remaining alloy raw materials in sequence, stir and keep the temperature at 740-760℃ for 20 minutes; 1.4 Refining treatment: Add special refining agent for aluminum alloy, stir evenly at 740-760℃, degas and let it stand; 1.5 Casting: The melt is cooled to 720℃, refined by adding refiner for modification, and then cast into ingots; S2. Heat treatment: 2.1 Solution treatment: keep the ingot at 390-500℃ for 4-24 hours; 2.2 Aging treatment: After solution treatment, the material is aged at 160-200℃ for 8-24 hours.

4. The method for preparing a high-temperature, controllable dissolution rate aluminum alloy according to claim 3, wherein: The Ga, In, Sn, Mg and Zn are all added in the form of pure metals tightly wrapped in aluminum foil, and the Cu, Zr and Ti are all added in the form of aluminum master alloy.

5. The method for preparing a high-temperature, controllable dissolution rate aluminum alloy according to claim 3, wherein: The inert gas introduced in step S1 is argon, and the refining agent is Al-Ti5-B1.

6. The method for preparing a high-temperature, controllable dissolution rate aluminum alloy according to claim 3, wherein: In step S1, the melt composition is tested before casting, and casting can be carried out only after the alloy composition is qualified.

7. The method for preparing a high-temperature, controllable dissolution rate aluminum alloy according to claim 3, wherein: In step S2, after the molten cast base material is placed in the resistance furnace, the temperature is raised from room temperature to a set temperature or the base material is directly placed in the resistance furnace at the set temperature.

8. The method for preparing a high-temperature, controllable dissolution rate aluminum alloy according to claim 3, wherein: The dissolution rate of the soluble aluminum alloy material with different compositions and heat treatment states is 4 to 400 mg / (h*cm2) under the dissolution conditions of 90°C / 3% KCl.

9. The method for preparing a high-temperature, controllable dissolution rate aluminum alloy according to claim 3, wherein: The tensile strength of the soluble aluminum alloy after solution treatment and aging treatment is 130 MPa to 220 MPa.

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