TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile prepared with assistance of electromagnetic stirring and preparation method of TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile

Abstract

The invention discloses a TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile prepared with the assistance of electromagnetic stirring and a preparation method of the TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile. The aluminum alloy profile comprises the following chemical components in percentage by weight: 9.0%-12.0% of Zn, 2.0%-3.5% of Mg, 0.6%-2.6% of Cu, 0.06%-2.0% of Zr, 0.05%-0.2% of Sc, 1.0%-3.0% of TiB2, less than or equal to 0.1% of Fe, less than or equal to 0.1% of Si, less than or equal to 0.05% of single other impurities, less than or equal to 0.15% of total impurities and the balance of Al. The yield strength of the bar can reach 790 Mpa, the ductility reaches 10%, and the prepared profile can be used in the fields of aviation, aerospace, transportation, consumer electronics and the like and has wide application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of metal materials, and in particular to an electromagnetic stirring assisted preparation of a TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile and a preparation method thereof. Background Art

[0002] As the demand for lightweight and high-strength structural materials in the future electronic consumer market becomes increasingly urgent, high-performance aluminum alloys have become a research hotspot. At present, the methods for preparing ultra-high-strength aluminum alloys include traditional melting and casting, rapid solidification / powder metallurgy, and spray forming. The preparation process of the latter two is relatively complex and the preparation cost is also high. At the same time, the specifications of semi-finished products are limited by the billet, which has affected their development to a certain extent. The traditional melting and casting method has a short process flow, low preparation cost, a full range of semi-finished products, and large specifications. It is still the aluminum alloy preparation method with the highest degree of engineering promotion.

[0003] Ultra-high aluminum alloys prepared by traditional smelting methods are mainly prepared by adding main alloying elements or introducing high modulus particles. However, increasing the content of alloying elements will inevitably aggravate the element segregation in the prepared material, easily causing hot cracks or macro segregation in large ingots, thereby reducing the product's qualification rate and plasticity. Recent studies have found that some ceramic particles such as ZrB2, TiN, B4C, Al3Ti, SiC, TiB2, TiC, etc. play a vital role in the solidification behavior, organization and properties of aluminum alloys. In particular, TiB2 has received widespread attention due to its stable interface bonding with the Al matrix, good high-temperature stability, and simple preparation method. At present, the methods of introducing TiB2 particles include direct addition and synthesis in the matrix using the melt self-propagating direct synthesis method.

[0004] At present, there is a related patent CN106367644A that introduces TiB2 into Al-Zn-Mg-Cu by melt self-propagating direct synthesis method. However, the melt self-propagating direct synthesis method introduces particles. In addition to the difficulty of controlling the uniformity and dispersibility of particle size, the most important thing is that by-products such as Al2O3 will be introduced, which will affect the further improvement of alloy strength. Direct addition can ensure the particle uniformity and cleanliness of TiB2 particles, which is very important for further improving alloy strength. Therefore, directly adding high modulus particles has become a relatively simple method, but the directly added micron-sized high modulus particles are easy to agglomerate in the alloy, which has become a difficulty of this method.

[0005] Therefore, it is necessary to propose a preparation process to solve the above problems and achieve high strength and high ductility of Al-Zn-Mg-Cu alloy, so that it has broad application prospects in aviation, aerospace, consumer electronics, transportation and other fields. Summary of the invention

[0006] The purpose of the present invention is to address the deficiencies of the prior art and provide an electromagnetic stirring assisted preparation of TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile and a preparation method thereof, so as to solve the problem of low elongation of existing ultra-high strength aluminum alloys.

[0007] In a first aspect, the present invention provides an electromagnetic stirring-assisted preparation of a TiB2 particle-reinforced Al-Zn-Mg-Cu aluminum alloy profile, comprising the following chemical components in weight percentage:

[0008] Zn 9.0%~12.0%, Mg 2.0%~3.5%, Cu 0.6%~2.6%, Zr 0.06%~2.0%, Sc0.05%~0.2%, TiB21.0%~3.0%, Fe≤0.1%, Si≤0.1%, other impurities individually ≤0.05%, total ≤0.15%, balance is Al.

[0009] In a second aspect, the present invention provides a method for preparing a TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile assisted by electromagnetic stirring, comprising the following steps:

[0010] Step 1, prepare the materials according to the following chemical components in weight percentage: Zn 9.0%-12.0%, Mg2.0%-3.5%, Cu 0.6%-2.6%, Zr 0.06%-2.0%, Sc 0.05%-0.2%, TiB21.0%-3.0%, Fe≤0.1%, Si≤0.1%, other impurities individually ≤0.05%, total ≤0.15%, and the balance is Al; add the ingredients except TiB2 particles into a medium frequency furnace with electromagnetic stirring, when all the alloy ingredients are melted, add CCl6 and introduce argon gas for degassing, repeat the degassing treatment twice, and then press the aluminum foil bag containing TiB2 particles into the melt;

[0011] Step 2: Turn on the magnetic field of the medium frequency furnace for stirring, and the stirring lasts for no less than 10 minutes; after the stirring is completed, pouring is performed to obtain a cylindrical ingot with a size of

[0012] Step 3: subjecting the electromagnetic assisted casting ingot to a homogenization process, peeling the homogenized ingot, and then subjecting it to hot extrusion, with the extrusion ratio controlled at 25 or above;

[0013] Step 4: The extruded profile is subjected to solution and aging heat treatment.

[0014] Furthermore, in the step 1, the melting is carried out in a smelting furnace, and the melting temperature is 690° C. to 750° C.;

[0015] The completely melted metal is refined, and the metal temperature is maintained in the range of 710℃~740℃ during refining;

[0016] After refining and passing argon gas, the steel is allowed to stand for no less than 10 minutes, and then the slag is removed;

[0017] After two refinings and argon gas deslagging, the aluminum foil package containing TiB2 particles is pressed into the melt.

[0018] Furthermore, the medium frequency furnace used in the step 2 is equipped with high and low frequency control modules. The high frequency module is used for heating. During stirring, only the low frequency is turned on for stirring. The low frequency power is set to 40-60Kw, the frequency is set to 80-130Hz, and the phase shift angle is set to 70-100 degrees. After stirring, casting is performed, the casting temperature is 690°C-700°C, and the casting speed is 20mm / min-50mm / min.

[0019] Furthermore, in the step 3, after homogenization is completed, the product is cooled in the furnace to below 300° C. and then air-cooled out of the furnace.

[0020] Furthermore, in the step three, the parameters during the hot extrusion process are: billet temperature 390° C. to 430° C., and extrusion speed 2 m / min to 10 m / min.

[0021] Furthermore, in the step 4, the solid solution is a two-stage solid solution system, the first stage solid solution temperature is 450°C to 470°C, and the second stage solid solution temperature is 470°C to 480°C; the aging adopts peak aging, and the process is: keeping warm at 110°C to 130°C for 12h to 24h.

[0022] The present invention has the following beneficial effects: the present invention provides an electromagnetic stirring assisted preparation of TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile and a preparation method thereof, the prepared aluminum alloy has a relatively uniform microstructure and stable performance, the tensile strength and yield strength of the rod can reach up to 790Mpa, the yield strength ratio is 1, and the elongation is higher than 10%. The profiles produced by this type of alloy can replace the low-ductility ultra-high strength aluminum alloy prepared by traditional casting methods, and the prepared profiles can be used in aviation, aerospace, transportation, electronic consumer products and other fields, and have broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 Schematic diagram of the process of preparing TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles assisted by electromagnetic stirring;

[0025] Figure 2 The homogenization diagram of the matrix alloy with and without the assistance of a magnetic field for the alloy composition of Example 1, wherein (a) is without the assistance of a magnetic field, and (b) is with the assistance of a magnetic field;

[0026] Figure 3 Schematic diagram of room temperature tensile properties of the rod obtained in Example 1;

[0027] Figure 4 Schematic diagram of the room temperature tensile properties of the rod obtained in Example 2. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art to which the present application belongs.

[0029] The present invention provides an electromagnetic stirring-assisted preparation of TiB2 particle-reinforced Al-Zn-Mg-Cu aluminum alloy profiles, comprising the following chemical components in weight percentage:

[0030] Zn 9.0%~12.0%, Mg 2.0%~3.5%, Cu 0.6%~2.6%, Zr 0.06%~2.0%, Sc0.05%~0.2%, TiB21.0%~3.0%, Fe≤0.1%, Si≤0.1%, other impurities individually ≤0.05%, total ≤0.15%, balance is Al.

[0031] See also Figure 1 The electromagnetic stirring-assisted preparation method of the TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profile of the present invention comprises the following steps:

[0032] Step 1, prepare the materials according to the following chemical components in weight percentage: Zn 9.0%-12.0%, Mg2.0%-3.5%, Cu 0.6%-2.6%, Zr 0.06%-2.0%, Sc 0.05%-0.2%, TiB21.0%-3.0%, Fe≤0.1%, Si≤0.1%, other impurities individually ≤0.05%, total ≤0.15%, and the balance is Al; add the ingredients except TiB2 particles into a medium frequency furnace with electromagnetic stirring, when all the alloy ingredients are melted, add CCl6 and introduce argon gas for degassing, repeat the degassing treatment twice, and then press the aluminum foil bag containing TiB2 particles into the melt.

[0033] Specifically, the casting process includes: melting in a smelting furnace at a melting temperature of 690°C to 750°C; refining the completely melted metal, maintaining the metal temperature in the range of 710°C to 740°C during refining; standing after refining and passing argon gas for a standing time of not less than 10 minutes, and slagging after standing.

[0034] Step 2: Turn on the magnetic field of the medium frequency furnace for stirring, and the stirring lasts for no less than 10 minutes; after the stirring is completed, pouring is performed to obtain a cylindrical ingot with an ingot size of

[0035] The magnetic field of the medium frequency furnace is turned on for stirring, and the stirring lasts for no less than 10 minutes. The melt is briefly allowed to stand, and when the melt temperature drops to 700°C to 710°C, pouring is performed.

[0036] Specifically, the medium frequency furnace used is equipped with high and low frequency control modules. The high frequency module is used for heating. During stirring, only the low frequency is turned on for stirring. The low frequency power is set to 40-60Kw, the frequency is set to 80-130Hz, and the phase shift angle is set to 70-100 degrees. After stirring, casting is performed. The casting temperature is 690℃~700℃ and the casting speed is 20mm / min~50mm / min.

[0037] Step 3: subject the electromagnetic assisted casting ingot to homogenization process, peel the homogenized ingot, and then perform hot extrusion, with the extrusion ratio controlled at 25 or above.

[0038] Specifically, the parameters during the hot extrusion process are: 390° C. to 430° C., and an extrusion speed of 2 m / min to 10 m / min.

[0039] Step 4: The extruded profile is subjected to solution and aging heat treatment.

[0040] Specifically, the solid solution in step 4 is a two-stage solid solution system, the first stage solid solution temperature is 450°C to 470°C, and the second stage solid solution temperature is 470°C to 480°C; the aging adopts peak aging, and its process is: keeping warm at 110°C to 130°C for 12h to 24h.

[0041] The present invention adopts electromagnetic stirring assisted method, and fully stirs the melt with the help of electromagnetic field in the casting stage, which can not only disperse TiB2 particles, but also evenly disperse the matrix alloy element solute atoms, and weaken the element segregation of high alloy aluminum alloy. Therefore, the introduction of electromagnetic stirring can solve the above problems, realize the high strength and high ductility of Al-Zn-Mg-Cu alloy, and make it have broad application prospects in the fields of aviation, aerospace, consumer electronics, transportation, etc.

[0042] The electromagnetic stirring assisted preparation of TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles and the preparation method thereof of the present invention are described in detail below in combination with several specific embodiments.

[0043] Embodiment 1:

[0044] The preparation process steps of the alloy are as follows:

[0045] (1) The alloy composition is as follows: Zn: 11.5%, Mg: 2.6%, Cu: 1% by weight; according to the above weight percentage, 99.99% refined Al ingot, pure Zn ingot, pure Mg ingot, Al-Cu master alloy and micron-sized TiB2 particles are used.

[0046] (2) Melting in a smelting furnace at a melting temperature of 690°C to 730°C.

[0047] (3) Refining agent is added to the completely melted metal for refining, and argon gas is passed after refining. During refining, the metal temperature is maintained in the range of 710°C to 730°C.

[0048] (4) After refining, allow the product to stand for 20 to 40 minutes with argon gas, and then remove the slag.

[0049] (5) Press the aluminum foil package containing TiB2 particles into the melt, and then turn on the low-frequency module of the medium-frequency furnace for electromagnetic stirring, and the stirring lasts for 10 minutes.

[0050] (6) After electromagnetic stirring, when the melt temperature drops to 700°C to 710°C, pouring is performed at a pouring speed of 20 mm / min to 40 mm / min.

[0051] (7) Casting to obtain a cylindrical ingot with a size of

[0052] (8) After homogenization, cool down with the furnace until the temperature drops below 300°C and then air cool down after being taken out of the furnace.

[0053] (9) peeling the homogenized ingot, the ingot diameter after peeling is 60 mm;

[0054] (10) Select a rod extrusion die to hot extrude the ingot with an extrusion ratio of 25.

[0055] (11) During the extrusion process, the initial heating temperature of the ingot is 400°C, the ingot temperature is controlled at 400°C to 420°C, and the extrusion speed is controlled at 5m / min to 10m / min.

[0056] (12) The extruded rods were subjected to a two-stage solution treatment, wherein the first stage solution treatment temperature was 465°C and the holding time was 2 h; the second stage solution treatment temperature was 475°C and the holding time was 1 h.

[0057] (13) The extruded profiles are subjected to peak aging heat treatment at a holding temperature of 120°C for 24 h and then air-cooled in the furnace.

[0058] The room temperature tensile properties of the rod obtained in Example 1 are shown in Table 1 below, where σ b is the tensile strength, σ 0.2 is the yield strength and δ is the elongation.

[0059] Table 1 Room temperature tensile properties of the rod obtained in Example 1

[0060]

[0061] Figure 2 The homogenization diagram of the alloy composition of Example 1 with and without magnetic field assistance, where (a) is without magnetic field assistance and (b) is with magnetic field assistance. Figure 2 The effect of the magnetic field on the highly alloyed base alloy can be seen in FIG. Figure 3 Schematic diagram of the room temperature tensile properties of the rod obtained in Example 1.

[0062] Embodiment 2:

[0063] (1) The alloy composition is as follows: Zn: 11.0%, Mg: 2.4%, Cu: 1% by weight; according to the above weight percentage, 99.99% refined Al ingot, pure Zn ingot, pure Mg ingot, Al-Cu master alloy and micron-sized TiB2 particles are used.

[0064] (2) Melting in a smelting furnace at a melting temperature of 720°C to 750°C.

[0065] (3) Refining agent is added to the completely melted metal and the mixture is continuously stirred for refining. Argon gas is passed through the mixture after refining, and the metal temperature is maintained within the range of 720°C to 740°C during refining.

[0066] (4) After refining, allow the product to stand for 10 to 20 minutes with argon gas, then remove the slag.

[0067] (5) Press the aluminum foil package containing TiB2 particles into the melt, and then turn on the low-frequency module of the medium-frequency furnace for electromagnetic stirring, and the stirring lasts for 20 minutes.

[0068] (6) After electromagnetic stirring, when the melt temperature drops to 700°C to 710°C, pouring is performed at a pouring speed of 30 mm / min to 50 mm / min.

[0069] (7) Casting to obtain a cylindrical ingot with a size of

[0070] (8) After homogenization, cool down with the furnace until the temperature drops below 300°C and then air cool down after being taken out of the furnace.

[0071] (9) The ingot is peeled after homogenization. The diameter of the ingot after peeling is 176 mm.

[0072] (10) Select a rod extrusion die to hot extrude the ingot with an extrusion ratio of 36.

[0073] (11) During the extrusion process, the initial heating temperature of the ingot is 410°C, the ingot temperature is controlled at 410°C to 430°C during the extrusion process, and the extrusion speed is controlled at 2m / min to 6m / min.

[0074] (12) The extruded rods are subjected to two-stage solution treatment, and the solution treatment system is as follows: the first stage solution treatment temperature is 460°C, the holding time is 3 h, and the second stage solution treatment temperature is 475°C, the holding time is 0.5 h.

[0075] (13) The extruded profiles are subjected to peak aging heat treatment at a holding temperature of 120°C for 18 h and then air-cooled in the furnace.

[0076] The room temperature tensile properties of the rods obtained in Example 2 are shown in Table 1 below, where σ b is the tensile strength, σ 0.2 is the yield strength and δ is the elongation.

[0077] Table 2 Room temperature tensile properties of the rods obtained in Example 2

[0078]

[0079] Figure 4 Schematic diagram of room temperature tensile properties of the profile obtained in Example 2.

[0080] From the above performance analysis, it can be seen that the electromagnetic stirring assisted preparation of TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles of the present invention has stable performance, a tensile strength higher than 780MPa, and an elongation higher than 8.6%. When the tensile strength is higher than 788MPa, the elongation of the plate is higher than 10.3%. It has broad application prospects in aviation, aerospace, transportation, electronic consumption and other fields.

[0081] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0082] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles assisted by electromagnetic stirring, characterized in that: The chemical composition includes the following weight percentages: Zn 9.0%~12.0%, Mg 2.0%~3.5%, Cu 0.6%~2.6%, Zr 0.06%~2.0%, Sc0.05%~0.2%, TiB21.0%~3.0%, Fe≤0.1%, Si≤0.1%, other impurities individually ≤0.05%, total ≤0.15%, balance is Al.

2. A method for preparing TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles assisted by electromagnetic stirring, characterized in that: The following steps are involved: Step 1, prepare the materials according to the following chemical components in weight percentage: Zn 9.0%-12.0%, Mg 2.0%-3.5%, Cu0.6%-2.6%, Zr 0.06%-2.0%, Sc 0.05%-0.2%, TiB21.0%-3.0%, Fe≤0.1%, Si≤0.1%, other impurities individually ≤0.05%, total amount ≤0.15%, and the balance is Al; add the ingredients except TiB2 particles into a medium frequency furnace with electromagnetic stirring, when all the alloy ingredients are melted, add CCl6 and introduce argon gas for degassing, repeat the degassing treatment twice, and then press the aluminum foil bag containing TiB2 particles into the melt; Step 2: Turn on the magnetic field of the medium frequency furnace for stirring, and the stirring lasts for no less than 10 minutes; after the stirring is completed, pouring is performed to obtain a cylindrical ingot with an ingot size of Step 3: subjecting the electromagnetic assisted casting ingot to a homogenization process, peeling the homogenized ingot, and then subjecting it to hot extrusion, with the extrusion ratio controlled at 25 or above; Step 4: The extruded profile is subjected to solution and aging heat treatment.

3. The method for preparing TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles assisted by electromagnetic stirring according to claim 2, characterized in that: In the step 1, melting is performed in a smelting furnace at a melting temperature of 690° C. to 750° C.; The completely melted metal is refined, and the metal temperature is maintained in the range of 710℃~740℃ during refining; After refining and passing argon gas, the steel is allowed to stand for no less than 10 minutes, and then the slag is removed; After two refinings and argon gas deslagging, the aluminum foil package containing TiB2 particles is pressed into the melt.

4. The method for preparing TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles assisted by electromagnetic stirring according to claim 2, characterized in that: The medium frequency furnace used in the step 2 is equipped with high and low frequency control modules. The high frequency module is used for heating. During stirring, only the low frequency is turned on for stirring. The low frequency power is set to 40-60Kw, the frequency is set to 80-130Hz, and the phase shift angle is set to 70-100 degrees. After stirring, casting is completed. The casting temperature is 690℃~700℃ and the casting speed is 20mm / min~50mm / min.

5. The method for preparing TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles assisted by electromagnetic stirring according to claim 2, characterized in that: In the step 3, after homogenization, the product is cooled in the furnace to below 300° C. and then air-cooled out of the furnace.

6. The method for preparing TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles assisted by electromagnetic stirring according to claim 2, characterized in that: In the step 3, the parameters during the hot extrusion process are: billet temperature 390° C. to 430° C., and extrusion speed 2 m / min to 10 m / min.

7. The method for preparing TiB2 particle reinforced Al-Zn-Mg-Cu aluminum alloy profiles assisted by electromagnetic stirring according to claim 2, characterized in that: In the step 4, the solid solution is a two-stage solid solution system, the first stage solid solution temperature is 450°C to 470°C, and the second stage solid solution temperature is 470°C to 480°C; the aging adopts peak aging, and the process is: keeping warm at 110°C to 130°C for 12h to 24h.

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