In-situ endogenous TiB2+ZrB2 particle refined aluminum-copper alloy and preparation method

Abstract

The invention belongs to the field of aluminum alloy materials, and relates to an in-situ endogenous TiB2 + ZrB2 particle refined aluminum-copper alloy and a preparation method thereof.The preparation method comprises the steps that high-purity Al is added into two crucibles respectively and heated to be melted, the temperature is increased to 700-750 DEG C, then high-purity Cu, high-purity Cd, Al-Mn alloy, Al-Ti alloy, Al-V alloy, Al-B alloy and Al-Zr alloy which are equal in mass are sequentially added, and a first melt and a second melt are formed; after the two melts are continuously heated to 800-850 DEG C, an Al-B alloy is added into the first melt, an Al-Ti alloy and an Al-Zr alloy are added into the second melt, the mass percent of B in each melt is 0.6-2.6%, the mass percent of Ti in each melt is 0.6-3.5%, and the mass percent of Zr in each melt is 0.8-4.1%, and heat preservation is conducted till complete melting is achieved; the first melt and the second melt are poured into a square crucible, stirred and subjected to heat preservation for 10-40 min; and the temperature of the mixed melt is adjusted to 720-740 DEG C, after the temperature of the melt is stable, the melt is poured into a mold preheated to 200 DEG C, and an aluminum alloy ingot with the small grain size is formed. The aluminum alloy grain refinement method has the characteristics of low cost, simple process, high grain refinement efficiency, stable grain refinement effect and the like.

Description

Technical Field

[0001] The present application belongs to the field of aluminum alloy materials, and relates to an aluminum-copper alloy with in-situ endogenous TiB2+ZrB2 particle refinement and a preparation method thereof. Background Art

[0002] Aluminum and its alloys possess low density, high specific strength, excellent corrosion resistance, and excellent electrical and thermal conductivity, holding significant application prospects in industries such as aerospace, rail transit, and storage and transportation. With the development and advancement of these industries, higher requirements are being placed on aluminum alloys in terms of strength, toughness, wear resistance, and heat resistance. Grain morphology has a significant impact on alloy properties. A fine, uniform, equiaxed grain structure improves the toughness and wear resistance of aluminum alloy castings, reduces casting defects, improves element segregation, and reduces the tendency to hot cracking. Adding micron- or nanometer-sized ceramic particles to aluminum melts is one of the key methods for refining grains and strengthening the matrix structure.

[0003] Currently, adding an Al-Ti-B grain refiner to the melt during production is a common grain refinement method. However, this method results in large particles that are difficult to disperse evenly in the melt, easily forming agglomerates and impairing material properties. Furthermore, the fluoride salt reaction method is often used to prepare particle-refined aluminum alloys, but this still presents problems such as large average particle size and a wide size distribution range. Furthermore, residual salts from the reaction are difficult to completely remove, affecting melt quality. The grain refinement effect and matrix properties of aluminum alloys are primarily affected by particle size, morphology, distribution, and type. A single reinforced particle is unlikely to comprehensively improve alloy properties, and it is necessary to study multiple particle-reinforced aluminum alloy materials. Summary of the Invention

[0004] The embodiment of the present application provides a method for preparing an aluminum-copper alloy by in-situ endogenous TiB2+ZrB2 particle refinement, which solves the problems of the existing preparation method in that the particles are easy to agglomerate and settle, are large in size and of a single type.

[0005] Another aspect of the embodiments of the present application further provides an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy.

[0006] This application is implemented in this way.

[0007] A method for preparing an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy, the method comprising:

[0008] S1, adding equal masses of pure aluminum ingots to two resistance furnaces respectively, heating to 700-750°C to melt, and then adding equal masses of high-purity copper, high-purity cadmium, Al-Mn alloy, Al-Ti alloy, Al-V alloy, Al-B alloy and Al-Zr alloy to the two resistance furnaces respectively to form melt one and melt two. The two melts have exactly the same composition, containing Cu: 4.6-5.3%, Mn: 0.3-0.5%, Ti: 0.15-0.35%, V: 0.05-0.3%, Cd: 0.15-0.25%, Zr: 0.15-0.25%, B: 0.005-0.6%, and the balance is Al; keeping the temperature for 20-30 minutes, adding C2Cl6 for refining and degassing, and standing for 10-20 minutes before skimming;

[0009] S2, heating melt 1 and melt 2 prepared in S1 to 800-850°C, adding Al-B alloy to melt 1, first adding Al-Ti alloy to melt 2, and then adding Al-Zr alloy after they are completely melted; wherein the mass percentage of B element in melt 1 is 0.6-2.6%, and the mass percentages of Ti element and Zr element in melt 2 are 0.6-3.5% and 0.8-4.1%, respectively; after the alloy is completely melted, stirring melt 1 and melt 2 evenly, then pouring melt 1 and melt 2 into a square crucible, and keeping them warm for 10-40 minutes, adjusting the temperature of the mixed melt to 720-740°C after the insulation is completed, applying mechanical stirring coupled ultrasonic vibration to the mixed melt, and then pouring it into a preheated mold for solidification and cooling to obtain an aluminum alloy ingot containing TiB2 and ZrB2 particles.

[0010] Furthermore, Al-B alloy is added to melt one, Al-Ti alloy is first added to melt two, and Al-Zr alloy is added after they are completely melted, including: the Al-B alloy, Al-Ti alloy and Al-Zr alloy are dried in advance, wrapped with aluminum foil with a thickness of 0.5-1 mm, and the alloy blocks are completely pressed into the aluminum liquid using a graphite bell jar.

[0011] Furthermore, the stirring rate of the mechanical stirring coupled with ultrasonic vibration is 300-500 r / min, the ultrasonic vibration frequency is 0-20 kHz, and the time is 0-5 min.

[0012] Furthermore, the total content of TiB2+ZrB2 particles contained in the aluminum alloy ingot is 1-5wt.%, of which TiB2 particles account for 20%-80% of the total mass of TiB2+ZrB2 particles, and the addition amount of Ti and Zr is determined by the total content of TiB2 and ZrB2 particles, and the ratios are Ti:B:TiB2=2.2:1:3.2 and Zr:B:ZrB2=4.2:1:5.2 respectively.

[0013] On the other hand, an embodiment of the present application provides an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy, which contains, in mass percentage, Cu: 4.6-5.3%, Mn: 0.3-0.5%, Ti: 0.15-0.35%, V: 0.05-0.3%, Cd: 0.15-0.25%, Zr: 0.15-0.25%, B: 0.005-0.6%, and the remainder is Al. The total content of TiB2+ZrB2 particles is 1-5wt.%, of which TiB2 particles account for 20%-80% of the total mass of TiB2+ZrB2 particles.

[0014] Furthermore, the addition amounts of Ti and Zr are determined by the total content of TiB2 and ZrB2 particles, and the ratios are Ti:B:TiB2=2.2:1:3.2 and Zr:B:ZrB2=4.2:1:5.2, respectively.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] Compared with traditional methods, the method of this application has fine particle size, high particle number density, small average grain size, and stable grain refinement effect. It can stably generate a large number of TiB2 and ZrB2 particles, which are evenly distributed in the matrix without obvious agglomeration.

[0017] The method has the advantages of simple process, low cost, good grain refining effect, and is easy to produce and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The grain morphology of the Al-Cu alloy provided in the embodiment of the present application without refinement treatment;

[0019] Figure 2 The grain morphology of the Al-Cu alloy provided in the application example after TiB2+ZrB2 particle refinement treatment. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0021] A method for preparing an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy, comprising:

[0022] S1. Add equal masses of pure aluminum ingots to two resistance furnaces respectively, heat them to 700-750℃ to melt, and then add equal masses of high-purity copper, high-purity cadmium, Al-Mn alloy, Al-Ti alloy, Al-V alloy, Al-B alloy and Al-Zr alloy to the two resistance furnaces respectively to form melt one and melt two. The two melts have exactly the same composition, containing Cu: 4.6-5.3%, Mn: 0.3-0.5%, Ti: 0.15-0.35%, V: 0.05-0.3%, Cd: 0.15-0.25%, Zr: 0.15-0.25%, B: 0.005-0.6%, and the balance is Al; keep warm for 20-30 minutes, add C2Cl6 for refining and degassing, let it stand for 10-20 minutes, and then skim off the slag; the equal mass here means that the amount added to the two resistance furnaces is the same.

[0023] It should be noted that the pure aluminum ingots mentioned here refer to those with a purity of 99.99% or higher. High-purity copper and high-purity cadmium both refer to those with a purity of 99.99% or higher. For Al-Mn alloys, Al-Ti alloys, Al-V alloys, Al-B alloys, and Al-Zr alloys, Al-Mn alloys are used as an example: an aluminum alloy with manganese as the primary alloying element, based on aluminum. The Mn content can vary, and this is not a limitation. The amounts of high-purity copper and high-purity cadmium, Al-Mn alloys, Al-Ti alloys, Al-V alloys, Al-B alloys, and Al-Zr alloys added are as follows: Cu: 4.6-5.3%, Mn: 0.3-0.5%, Ti: 0.15-0.35%, V: 0.05-0.3%, Cd: 0.15-0.25%, Zr: 0.15-0.25%, B: 0.005-0.6%, with the balance being Al. Calculations show that Cu: 4.6-5.3%, Mn: 0.3-0.5%, Ti: 0.15-0.35%, V: 0.05-0.3%, Cd: 0.15-0.25%, Zr: 0.15-0.25%, B: 0.005-0.6%, and the remainder is the amount of Al added.

[0024] S2, heat the melt 1 and melt 2 prepared in S1 to 800-850°C, add Al-B alloy to melt 1, add Al-Ti alloy to melt 2 first, and then add Al-Zr alloy after they are completely melted; the mass percentage of B element in melt 1 is 0.6-2.6%, and the mass percentages of Ti element and Zr element in melt 2 are 0.6-3.5% and 0.8-4.1%, respectively; after the alloy is completely melted, stir melt 1 and melt 2 evenly, then pour melt 1 and melt 2 into a square crucible and keep them warm for 10-40 minutes. During the process of pouring melt 1 and melt 2 into the square crucible, a graphite funnel is required to drain so that the aluminum melt is filled smoothly from the bottom of the square crucible to avoid air entrapment; and the square crucible and graphite funnel must be preheated in advance. After the insulation is completed, the temperature of the mixed melt is adjusted to 720-740°C, and mechanical stirring coupled with ultrasonic vibration is applied to the mixed melt. It is then poured into a preheated mold for solidification and cooling to obtain an aluminum alloy ingot containing TiB2 and ZrB2 particles.

[0025] Similarly, the amount of Al-B alloy added to melt one satisfies that the mass percentage of B element in melt one is 0.6-2.6%, and the amount of Al-Ti alloy added to melt two satisfies that the mass percentages of Ti element and Zr element in melt two are 0.6-3.5% and 0.8-4.1% respectively.

[0026] The mixed melt refers to the melt formed by pouring melt 1 and melt 2 into a square crucible.

[0027] Among them, Al-B alloy is added to melt one, Al-Ti alloy is first added to melt two, and Al-Zr alloy is added after they are completely melted. The method includes: the Al-B alloy, Al-Ti alloy and Al-Zr alloy are dried in advance, wrapped with aluminum foil with a thickness of 0.5-1 mm, and the alloy blocks are completely pressed into the aluminum liquid using a graphite bell jar.

[0028] The stirring rate of mechanical stirring coupled with ultrasonic vibration is 300-500 r / min, the ultrasonic vibration frequency is 0-20 kHz, and the time is 0-5 min.

[0029] The obtained aluminum alloy ingot has TiB2 particles with a higher elastic modulus and ZrB2 particles with a lower thermal expansion coefficient. The total content of TiB2+ZrB2 particles is 1-5wt.%, of which TiB2 particles account for 20%-80% of the total mass of TiB2+ZrB2 particles. The addition amount of Ti and Zr is determined by the total content of TiB2 and ZrB2 particles, and the ratios are Ti:B:TiB2=2.2:1:3.2 and Zr:B:ZrB2=4.2:1:5.2 respectively.

[0030] The resulting aluminum alloy ingot has fine TiB2+ZrB2 particles, a high particle number density, a small average grain size, and a stable grain refinement effect. A large number of TiB2 and ZrB2 particles can be stably generated and evenly distributed in the matrix without significant agglomeration.

[0031] In the obtained aluminum alloy ingot, TiB2 and ZrB2 particles are evenly distributed in the aluminum matrix. As the holding time is extended from 10 min to 40 min, the particle size distribution range increases from 300 nm-1.5 μm to 300 nm-2 μm, and the particle shape is polygonal or hexagonal.

[0032] Example 1

[0033] A method for preparing an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy comprises the following steps:

[0034] S1 adds equal masses of pure aluminum ingots into two well-type resistance furnaces respectively, heats them to 700℃ to melt, and then adds equal masses of high-purity copper, high-purity cadmium, Al-Mn alloy, Al-Ti alloy, Al-V alloy, Al-B alloy and Al-Zr alloy into the two resistance furnaces in turn to form melt one and melt two. The compositions of the two melts are exactly the same, and their mass percentages are Cu: 4.6%, Mn: 0.3%, Ti: 0.15%, V: 0.05%, Cd: 0.15%, Zr: 0.15%, B: 0.005%, and the balance is Al. Keep warm for 20 minutes, add C2Cl6 for refining and degassing, and let it stand for 10 minutes before skimming.

[0035] In step S2, melts 1 and 2 prepared in step S1 are heated to 800°C. Al-B alloy is added to melt 1, while Al-Ti alloy is first added to melt 2. Once completely melted, an Al-Zr alloy is added. The Al-B, Al-Ti, and Al-Zr alloys are dried in advance, and the entire alloy block is pressed into the molten aluminum using a graphite bell jar. The mass percentage of B in melt 1 is 0.6-2.6%, while the mass percentages of Ti and Zr in melt 2 are 0.6% and 0.8%, respectively. Once the alloys are completely melted, melts 1 and 2 are stirred evenly. Then, melts 1 and 2 are poured into a square crucible and held at this temperature for 10-40 minutes. After the holding period, the temperature of the mixed melt is adjusted to 720°C. Mechanical stirring coupled with ultrasonic vibration is applied to the mixed melt, and the mixed melt is then poured into a mold preheated to 200°C for solidification and cooling, resulting in an aluminum alloy ingot containing TiB2 and ZrB2 particles.

[0036] The TiB2 and ZrB2 particles in the ingot are evenly distributed in the aluminum matrix. As the holding time increases from 10 min to 40 min, the particle size distribution range increases from 300 nm-1.5 μm to 300 nm-2 μm, and the particle shape is polygonal or hexagonal.

[0037] Mechanical stirring was coupled with ultrasonic vibration, with a stirring rate of 300 r / min, an ultrasonic vibration frequency of 10 kHz, and a time of 2 min.

[0038] In the process of adding Al-B alloy, Al-Ti alloy and Al-Zr alloy into aluminum melt, they need to be wrapped with aluminum foil with a thickness of 0.5 mm.

[0039] Example 2

[0040] Different from Example 1, a method for preparing an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy comprises the following steps:

[0041] S1 adds equal masses of pure aluminum ingots into two pit-type resistance furnaces respectively, heats them to 750℃ to melt, and then adds equal masses of high-purity copper, high-purity cadmium, Al-Mn alloy, Al-Ti alloy, Al-V alloy, Al-B alloy and Al-Zr alloy into the two resistance furnaces in turn to form melt one and melt two. The compositions of the two melts are exactly the same, and their mass percentages are Cu: 5.3%, Mn: 0.5%, Ti: 0.35%, V: 0.3%, Cd: 0.25%, Zr: 0.25%, B: 0.6%, and the balance is Al. Keep warm for 30 minutes, add C2Cl6 for refining and degassing, and let it stand for 10-20 minutes before skimming.

[0042] In step S2, melts 1 and 2 prepared in step S1 are heated to 850°C. Al-B alloy is added to melt 1, and Al-Ti alloy is first added to melt 2. After complete melting, Al-Zr alloy is added. The Al-B alloy, Al-Ti alloy, and Al-Zr alloy are dried in advance, and the entire alloy block is pressed into the molten aluminum using a graphite bell jar. The mass percentage of B element in melt 1 is 2.6%, and the mass percentages of Ti and Zr elements in melt 2 are 0.6-3.5% and 0.8-4.1%, respectively. After the alloys are completely melted, melts 1 and 2 are stirred evenly, then poured into a square crucible and held at this temperature for 10-40 minutes. After the holding period, the temperature of the mixed melt is adjusted to 740°C, and the mixed melt is subjected to mechanical stirring coupled with ultrasonic vibration. The mixed melt is then poured into a mold preheated to 200°C for solidification and cooling, resulting in an aluminum alloy ingot containing TiB2 and ZrB2 particles.

[0043] Example 3

[0044] (1) Add equal masses of pure aluminum ingots to two pit-type resistance furnaces respectively, heat to 740℃ and melt, then add equal masses of high-purity copper, high-purity cadmium, Al-Mn alloy, Al-Ti alloy, Al-V alloy, Al-B alloy and Al-Zr alloy to the two resistance furnaces respectively to form melt 1 and melt 2. The compositions of the two melts are exactly the same, and their mass percentages are Cu: 4.6-5.3%, Mn: 0.4%, Ti: 1.25%, V: 0.2%, Cd: 0.2%, Zr: 0.21%, B: 0.4%, and the balance is Al. Keep warm for 20-30 minutes, add C2Cl6 for refining and degassing, and let it stand for 10-20 minutes before slagging.

[0045] (2) Melt 1 and Melt 2 prepared in step S1 are heated to 800-850°C, Al-B alloy is added to Melt 1, Al-Ti alloy is first added to Melt 2, and Al-Zr alloy is added after they are completely melted; wherein the Al-B alloy, Al-Ti alloy and Al-Zr alloy need to be dried in advance, and the alloy blocks are all pressed into the aluminum liquid using a graphite bell jar. The mass percentage of B element in Melt 1 is 02.1%, and the mass percentages of Ti element and Zr element in Melt 2 are 2.5% and 3.1%, respectively. After the alloys are completely melted, Melt 1 and Melt 2 are stirred evenly, and then Melt 1 and Melt 2 are poured into a square crucible and kept warm for 10-40 minutes. After the holding period is completed, the temperature of the mixed melt is adjusted to 730°C, and mechanical stirring coupled with ultrasonic vibration is applied to the mixed melt. Subsequently, the mixed melt is poured into a mold preheated to 200°C for solidification and cooling to obtain an aluminum alloy ingot containing TiB2 and ZrB2 particles.

[0046] The TiB2 and ZrB2 particles in the ingot are evenly distributed in the aluminum matrix. As the holding time increases from 10 min to 40 min, the particle size distribution range increases from 300 nm-1.5 μm to 300 nm-2 μm, and the particle shape is polygonal or hexagonal.

[0047] Figure 1 The grain morphology of the Al-Cu alloy provided in the embodiment of the present application without refinement treatment;

[0048] Figure 2 The Al-Cu alloy grain morphology after TiB2+ZrB2 particle refinement treatment is provided in the application example. Figure 2 It can be seen that a large number of TiB2 and ZrB2 particles are generated and evenly distributed in the matrix without obvious agglomeration.

[0049] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for preparing an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy, characterized in that: The method includes: S1, adding equal masses of pure aluminum ingots to two resistance furnaces respectively, heating to 700-750°C to melt, and then adding equal masses of high-purity copper, high-purity cadmium, Al-Mn alloy, Al-Ti alloy, Al-V alloy, Al-B alloy and Al-Zr alloy to the two resistance furnaces respectively to form melt one and melt two. The two melts have exactly the same composition, containing Cu: 4.6-5.3%, Mn: 0.3-0.5%, Ti: 0.15-0.35%, V: 0.05-0.3%, Cd: 0.15-0.25%, Zr: 0.15-0.25%, B: 0.005-0.6%, and the balance is Al; keeping the temperature for 20-30 minutes, adding C2Cl6 for refining and degassing, and standing for 10-20 minutes before skimming; S2, heating melt 1 and melt 2 prepared in S1 to 800-850°C, adding Al-B alloy to melt 1, first adding Al-Ti alloy to melt 2, and then adding Al-Zr alloy after they are completely melted; wherein the mass percentage of B element in melt 1 is 0.6-2.6%, and the mass percentages of Ti element and Zr element in melt 2 are 0.6-3.5% and 0.8-4.1%, respectively; after the alloy is completely melted, stirring melt 1 and melt 2 evenly, then pouring melt 1 and melt 2 into a square crucible, and keeping them warm for 10-40 minutes, adjusting the temperature of the mixed melt to 720-740°C after the insulation is completed, applying mechanical stirring coupled ultrasonic vibration to the mixed melt, and then pouring it into a preheated mold for solidification and cooling to obtain an aluminum alloy ingot containing TiB2 and ZrB2 particles.

2. The method for preparing an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy according to claim 1, characterized in that: Al-B alloy is added to melt one, Al-Ti alloy is first added to melt two, and Al-Zr alloy is added after the melt is completely melted. The method comprises: drying the Al-B alloy, Al-Ti alloy and Al-Zr alloy in advance, wrapping them with aluminum foil with a thickness of 0.5-1 mm, and pressing the alloy blocks into the aluminum liquid with a graphite bell jar.

3. The method for preparing an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy according to claim 1, characterized in that: The mechanical stirring coupled with ultrasonic vibration has a stirring rate of 300-500 r / min, an ultrasonic vibration frequency of 0-20 kHz, and a duration of 0-5 min.

4. The method for preparing an in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy according to claim 1, characterized in that: The total content of TiB2+ZrB2 particles contained in the aluminum alloy ingot is 1-5wt.%, of which TiB2 particles account for 20%-80% of the total mass of TiB2+ZrB2 particles. The addition amount of Ti and Zr is determined by the total content of TiB2 and ZrB2 particles, and the ratios are Ti:B:TiB2=2.2:1:3.2 and Zr:B:ZrB2=4.2:1:5.2 respectively.

5. An in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy, characterized in that: According to mass percentage, it contains Cu: 4.6-5.3%, Mn: 0.3-0.5%, Ti: 0.15-0.35%, V: 0.05-0.3%, Cd: 0.15-0.25%, Zr: 0.15-0.25%, B: 0.005-0.6%, and the balance is Al. The total content of TiB2+ZrB2 particles is 1-5wt.%, of which TiB2 particles account for 20%-80% of the total mass of TiB2+ZrB2 particles.

6. The in-situ endogenous TiB2+ZrB2 particle-refined aluminum-copper alloy according to claim 5, characterized in that: The addition amount of Ti and Zr is determined by the total content of TiB2 and ZrB2 particles, and the ratios are Ti:B:TiB2=2.2:1:3.2 and Zr:B:ZrB2=4.2:1:5.2 respectively.

Images