CN116334459A - Micro-nano particle reinforced aluminum-based wire based on electro-plasticity and preparation method thereof - Google Patents

Abstract

An electro-plasticity-based micro-nano particle reinforced aluminum-based wire and a preparation method thereof relate to the technical field of aluminum-based wires, and the wire contains TiB ₂ TiC strengthening particles, the weight percentage of which is as follows; 7.5-11.2wt.% Zn,2.08-2.73wt.% Mg,2.15-2.30wt.% Cu,0.1-0.5wt.% Si,0.1-0.12wt.% Zr,0.5-7wt.% Ti,0.25-2.1wt.% B,0.5-2wt.% C,1.25-15wt.% K,0.05-0.2wt.% F, the balance being Al. Smelting an aluminum-based materialThen preparing an aluminum base line blank by a continuous semi-solid rheological extrusion technology, and then introducing current with specific magnitude and frequency and subsequent surface treatment in different drawing processes by a plurality of drawing processes.

Description

A micro-nano particle-reinforced aluminum-based wire based on electroplasticity and its preparation method

technical field

The invention relates to the technical field of aluminum-based wires, in particular to a micro-nano particle-reinforced aluminum-based wire based on electroplasticity and a preparation method thereof

Background technique

Aluminum alloy is an alloy formed by adding alloying elements to pure aluminum material. The addition of alloying elements improves the performance of pure aluminum, making it widely used in various industries. Aluminum alloy has the characteristics of light material, high strength, good thermal conductivity, and good processing performance. Compared with stainless steel materials, it can be better used in industries such as automobile manufacturing and aerospace manufacturing. Due to the addition of alloying elements and the difference in heat treatment process, there are many kinds of aluminum alloys. Among them, the high-strength aluminum alloy refers to an aluminum alloy to which a certain amount of elements such as chromium, zinc, and magnesium are added. These elements increase the tensile strength and yield strength of aluminum alloys by affecting grain nucleation and dendrite growth. However, aluminum alloys have the characteristics of high relative content of alloying elements, paste solidification, and serious element segregation. High-strength aluminum alloys are generally used in industrial production in the form of structural parts, because high-strength aluminum alloys have poor weldability.

Common welding processes for aluminum alloys include arc welding, solid phase welding, and laser welding. Among them, gas metal arc welding (MIG) is the most commonly used welding process for aluminum alloys, which has the advantages of high productivity and good weld formation. Friction stir welding is also a common welding method for aluminum alloys. It has the advantages of small structural changes in the heat-affected zone and low residual stress, but it also has obvious disadvantages. These disadvantages make it inferior to MIG in practical applications. The heat of aluminum alloy laser welding is low, the speed is fast, and the solidification speed is fast during welding, resulting in many defects such as pores and cracks. There are two main categories of defects that can occur in the additive manufacturing of metals: porosity and cracks. Solving the defects of the welding process can start with improved fusion welding and additives. Therefore, reasonable matching of welding materials or wires is required to avoid various problems during welding.

Contents of the invention

The invention proposes an electroplastic-based micro-nano particle-reinforced aluminum-based wire material and a preparation method thereof. The use of the wire can reduce problems such as cracks and joint weakening during welding and material addition, improve weld strength, and reduce weld crack sensitivity. Using the manufacturing method can improve the plasticity of the wire while ensuring the production efficiency of the wire, reduce defects inside the wire, make the structure inside the wire uniform, and generate reinforcing particles uniformly dispersed in the wire.

In order to solve the above technical problems, the present invention adopts the following technical solutions to realize:

The technical solution in the first aspect: the proposed electroplastic-based micro-nano-scale particle-reinforced aluminum-based wire contains Ti B ₂ and TiC reinforced particles, and the weight percentage of the raw material elements of the micro-nano-scale particle-reinforced aluminum-based wire is: 7.5-11.2 wt.% Zn, 2.08-2.73wt.% Mg, 2.15-2.30wt.% Cu, 0.1-0.5wt.% Si, 0.1-0.12wt.% Zr, 0.5-7wt.% Ti, 0.25-5.3wt.% B, 0.5-2wt.% C, 1.25-15wt.% K, 0.05-0.2wt.% F, the balance being Al.

The technical solution in the second aspect: a new aluminum-based wire preparation solution is proposed. The aluminum-based material is smelted, and then the aluminum baseline blank is prepared by continuous semi-solid rheological extrusion technology, and then undergoes multiple drawing processes, and currents of specific sizes and frequencies are passed through different drawing processes; The order of the board is to draw once, the shrinkage rate of the first drawing is 30-40%, then the second drawing, the shrinkage rate of the second drawing is 40-50%, and finally three times of drawing, three times of drawing The shrinkage rate is 70%-80%. After drawing to 1.2mm, carry out subsequent surface treatment and coiling; the shrinkage ratio refers to the ratio of the diameter of the cross-section of the wire after shrinkage to the original diameter of the cross-section. For example, the shrinkage ratio of 80% means that the diameter of the cross-section of the wire becomes 80 %. Specific steps are as follows:

S1: Melt pure aluminum at 700-800°C in a melting furnace, then add K ₂ TiF ₄ and KBF ₄ mixed salt, copper grains, Al-Si master alloy, magnesium grains, zinc grains, and graphite powder in sequence, and squeeze The Al-Zr alloy pressed into 10mm wire is inserted into the aluminum melt at 10mm/min, and then the melt is purified.

S2: Cool the aluminum melt prepared in S1 to 750°C for heat preservation, inject it into a continuous rheological extruder at 640°C-735°C, and prepare an aluminum-based wire rod with a diameter of 10-12mm.

S3: The aluminum-based wire is drawn, and a unidirectional continuous pulse current is introduced into the wire through two flexible conductive fixtures. Firstly, a drawing is performed. During a drawing process, the average current is 40-50A, the pulse width is 30ms, the pulse interval is 10ms, and the frequency is 50Hz. The shrinkage rate of a drawing is 30%-40%. Then carry out the second drawing, in the second drawing process, the average current is 30-40A, the pulse width is 20ms, the pulse interval is 10ms, the pulse current is 50Hz, and the shrinkage rate of the second drawing is 40%- 50%, and then three times of drawing, the shrinkage rate of the three times of drawing is 70-80%, in the process of three times of drawing, the average current is 20-30A, the pulse width is 10ms, the pulse interval is 10ms, and the frequency is 50Hz pulse current, increase the elongation of the wire, and ensure the efficiency of wire drawing. The above-mentioned pulse currents are all unidirectional and in the same direction as the aluminum-based wire.

S4: The wire rod obtained in step S3 is further subjected to other surface treatments such as scraping and winding, and then coiled to obtain a wire rod with a smooth surface, good wire feedability, and high performance.

The technical solution in the third aspect: a flexible conductive fixture based on electroplasticity is invented, which includes a copper square shell with a U-shaped cross section, and a plurality of copper cylinders are arranged on the inner surface of the copper square shell of the U-shaped cavity. A copper cylinder forms a copper brush, and the end face of the entire copper brush forms a semi-cylindrical cavity, two copper square shells are interlocked, and the wire is clamped in the semi-cylindrical cavity. The copper square housing contains 140-200 copper brushes, 70-100 on one side. The copper cylinder and the copper square shell are fixedly connected by a spring, and shrink into the copper square shell with the size of the wire in the fixture. The distance between the two flexible clamps is limited to 60-90 cm. Flexible conductive clamps are respectively arranged at both ends of the aluminum-based wire to clamp the aluminum-based wire. Pass the current through the conductive fixture.

Compared with the current technology, the electroplastic-based micro-nano particle-reinforced aluminum-based wire and its preparation method have the following advantages and beneficial effects.

(1) Adding a specific frequency and size pulse current during the drawing process produces an electroplastic effect. Solve the problems of high-strength aluminum-based wires with high deformation resistance, low plasticity and particle-reinforced aluminum-based wires with low elongation and easy cracking during the drawing process in the traditional drawing process, so that the drawn wires have no cracks and the surface is smooth and thick It is more uniform and does not require the intermediate annealing process of traditional drawing. Moreover, under the same drawing conditions as traditional drawing (drawing speed, drawing force), electroplasticity reduces the critical shrinkage rate of the wire without cracks, reducing the cracking tendency of the wire.

(2) TiB ₂ , TiC micro- and nano-scale second phase particles were generated by in-situ synthesis during the wire drawing process. The addition of pulse current promotes the change of material structure and the formation of micro-nano second-phase particles. During welding, the wire rod manufactured by the invention injects micro- and nano-scale second-phase particles into the high-temperature molten pool, which promotes the heterogeneous nucleation effect and refines the solidification structure. At the same time, it also promotes the release of the local tensile stress formed in the thermal processing engineering in the micro-zone, thereby inhibiting the welding cracks that are easy to occur in traditional welding and additive materials.

(3) The comprehensive performance of welding and additive high-strength aluminum alloy samples is improved. The addition of micro- and nano-scale particles refines the matrix structure of the sample and thus improves the strength of the alloy. Among them, TiC and TiB ₂ particles have a synergistic strengthening effect, and the addition of TiC particles improves the hardness of the sample and improves the strength of the sample. wear resistance.

(4) Invented a flexible conductive fixture based on electroplasticity. The fixture fits the surface of the wire rod, adapts to wire rods of various sizes, has good conductivity, reduces the shaking of the wire rod during the wire drawing process, and has low cost and strong applicability. .

Description of drawings

Fig. 1 is a flow chart of the preparation of an aluminum-based wire material according to the present invention.

Fig. 2 is an overall schematic diagram of a flexible conductive fixture based on electroplasticity according to the present invention.

Fig. 3 is a schematic diagram of one side of a flexible conductive fixture based on electroplasticity in the present invention.

Marks in the figure: 1, fixture; 2, wire.

3. Copper brush; 4. Copper shell.

Specific implementation method

Through the following examples, the technical means, inventive features and implementation advantages of the present invention are further described.

Example 1

An electroplastic-based micro-nano particle-reinforced aluminum-based wire, the weight percentage of which contains the following elements: 8.2wt% Zn, 2.12wt% Mg, 2.15wt% Cu, 0.2wt% Si, 0.1wt% Zr, 5.2wt% Ti, 4.2wt% B, 1.5wt% C, 14.5wt.% K, 0.05wt.% F, the balance being Al.

The preparation method of the electroplastic-based micro-nano-scale particle reinforced aluminum-based wire of Example 1, the specific steps are as follows:

S1: Melt pure aluminum at 750°C in a melting furnace, then add K ₂ TiF ₄ and KBF ₄ mixed salt, copper particles, Al-Si master alloy, magnesium particles, zinc particles, graphite powder in sequence, and extrude into The Al-Zr alloy of 10mm wire is inserted into the aluminum melt at 10mm/min, and then the melt is purified.

S2: Cool the aluminum melt prepared in S1 to about 750°C for heat preservation, and inject it into a continuous rheological extruder at 660°C to prepare an aluminum-based wire rod with a diameter of 10mm.

S3: The aluminum-based wire is drawn, and a unidirectional continuous pulse current is introduced into the wire through two flexible conductive fixtures. Firstly, a drawing is performed, and a pulse current with an average current of 50A, a pulse width of 30ms, a pulse interval of 10ms, and a frequency of 50Hz is applied. The shrinkage rate of the first drawing is 30%, and then the second drawing is performed. During the unplugging process, a pulse current with an average current of 30A, a pulse width of 20ms, a pulse interval of 10ms, and a frequency of 50Hz was fed. The shrinkage rate of the second drawing is 50%, and then the third drawing is performed. During the three-time drawing process, a pulse current with an average current of 20A, a pulse width of 10ms, a pulse interval of 10ms, and a frequency of 50Hz was applied to improve the plasticity and elongation of the wire. The shrinkage rate of the three-time drawing was 80%, and the final drawing into 1.2mm wire.

S4: The wire obtained in the step S3 is further subjected to other surface treatments for scraping and winding, and then coiled to obtain a particle-reinforced aluminum-based wire with a smooth surface, good wire feedability, and high performance.

The manufactured wire has good wire feedability, and the tensile strength of the wire is 131Mpa. The wire is used to weld 7075 aluminum alloy, and the strength of the welded joint after heat treatment (aging at 180°C×2 hours) is 335Mpa. The plasticity is improved during the drawing process, the crack-free critical shrinkage rate of the first drawing can reach 30%, the second drawing can reach 50%, and the third drawing can reach 80%.

Example 2

An electroplastic-based micro-nano particle-reinforced aluminum-based wire, the weight percentage of which contains the following elements: 9wt% Zn, 2.08wt% Mg, 2.2wt% Cu, 0.1wt% Si, 0.1wt% Zr, 3.5 wt%Ti, 3wt%B, 2wt%C, 10wt.%K, 0.07wt.%F and the balance is Al.

The preparation method of the electroplastic-based micro-nano-scale particle reinforced aluminum-based wire of Example 2, the specific steps are as follows:

S1: Melt pure aluminum at 800°C in a melting furnace, then add K ₂ TiF ₄ and KBF ₄ mixed salt, copper particles, Al-Si master alloy, magnesium particles, zinc particles, graphite powder in sequence, and extrude into The Al-Zr alloy of 10mm wire is inserted into the aluminum melt at 10mm/min, and then the melt is purified.

S2: Cool the aluminum melt prepared in S1 to about 750°C for heat preservation, and inject it into a continuous rheological extruder at 680°C to prepare an aluminum-based wire rod with a diameter of 12mm.

S3: The aluminum-based wire is drawn, and a unidirectional continuous pulse current is introduced into the wire through two flexible conductive fixtures. Firstly, a drawing is carried out, and a pulse current with an average current of 40A, a pulse width of 3ms, a pulse interval of 10ms, and a frequency of 50Hz is applied. The shrinkage rate of the first drawing is 33%, and then the second drawing is performed. During the unplugging process, a pulse current with an average current of 40A, a pulse width of 20ms, a pulse interval of 10ms, and a frequency of 50Hz was fed. The shrinkage of the second drawing was 43%, followed by three drawing. During the three-time drawing process, the average current is 30A, the pulse width is 10ms, the pulse current is 10ms, and the frequency is 50Hz pulse current, which improves the plasticity and elongation of the wire. The shrinkage rate of the three-time drawing is 70%, and the final drawing is finished. 1.2mm wire.

S4: The wire rod obtained in step S3 is further subjected to scraping and other surface treatments and coiled to obtain a particle-reinforced aluminum-based wire rod with a smooth surface, good wire feedability, and high performance.

The manufactured wire has good wire feedability, and the tensile strength of the wire is 129Mpa. The wire is used to weld 7075 aluminum alloy, and the strength of the welded joint after heat treatment (aging at 180°C×2 hours) is 325Mpa. The plasticity is improved during the drawing process, the crack-free critical shrinkage rate of the first drawing can reach 33%, the second drawing can reach 43%, and the third drawing can reach 70%.

Example 3

An electroplastic-based micro-nano particle-reinforced aluminum-based wire, the weight percentage of which contains the following elements: 10wt% Zn, 2.33wt% Mg, 2.30wt% Cu, 0.5wt% Si, 0.1wt% Zr, 2.9 wt%Ti, 4.8wt%B, 0.5wt%C, 7.5wt.%K, 0.05wt.%F and the balance is Al.

The preparation method of the electroplastic-based micro-nano-scale particle reinforced aluminum-based wire of Example 3, the specific steps are as follows:

S1: Melt pure aluminum at 780°C in a melting furnace, then add K ₂ TiF ₄ and KBF ₄ mixed salt, copper particles, Al-Si master alloy, magnesium particles, zinc particles, and graphite powder in sequence, and extrude into The Al-Zr alloy of 10mm wire is inserted into the aluminum melt at 10mm/min, and then the melt is purified.

S2: Cool the aluminum melt prepared in S1 to about 750°C for heat preservation, and inject it into a continuous rheological extruder at 735°C to prepare an aluminum-based wire rod with a diameter of 10mm.

S3: The aluminum-based wire is drawn, and a unidirectional continuous pulse current is introduced into the wire through two flexible conductive fixtures. Firstly, a drawing is carried out, and a pulse current with an average current of 45A, a pulse width of 30 ms, a pulse interval of 10 ms, and a frequency of 50 Hz is introduced. The shrinkage rate of the first drawing is 40%, and then the second drawing is performed. During the unplugging process, a pulse current with an average current of 35A, a pulse width of 20ms, a pulse interval of 10ms, and a frequency of 50Hz was fed. The shrinkage rate of the second drawing is 40%, and then the third drawing is performed. In the three-time drawing process, the average current is 25A, the pulse width is 10ms, the pulse current is 10ms, and the frequency is 50Hz pulse current, which improves the elongation of the wire and ensures the efficiency of wire drawing. The shrinkage rate of the three-time drawing is 75 % or so, and finally drawn into a 1.2mm wire.

S4: The wire rod obtained in step S3 is further subjected to scraping and other surface treatments and coiled to obtain a particle-reinforced aluminum-based wire rod with a smooth surface, good wire feedability, and high performance.

The manufactured wire rod has good wire feedability, and the tensile strength of the wire rod is 135Mpa. The wire rod is used to weld 7075 aluminum alloy, and the strength of the welded joint after heat treatment (aging at 180°C×2 hours) is 347Mpa. The plasticity is improved during the drawing process, the crack-free critical shrinkage rate of the first drawing can reach 40%, the second drawing can reach 40%, and the third drawing can reach 75%.

It should be noted that the above is only a specific embodiment with better effect in the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the present invention Any equivalent replacement or change of the technical solutions and their inventive concepts shall fall within the protection scope of the present invention.

Claims (4)

1. A micronano-scale particle-reinforced aluminum-based wire based on electroplasticity, characterized in that the aluminum-based wire contains TiB ₂ , TiC strengthening particles, and the weight percentage of the raw material elements of the micronano-scale particle-reinforced aluminum-based wire is: 7.5 -11.2wt.% Zn, 2.08-2.73wt.% Mg, 2.15-2.30wt.% Cu, 0.1-0.5wt.% Si, 0.1-0.12wt.% Zr, 0.5-7wt.% Ti, 0.25-5.3wt .%B, 0.5-2wt.%C, 1.25-15wt.%K, 0.05-0.2wt.%F, and the balance is Al. 2. according to the preparation method of a kind of electroplasticity-based micro-nano particle reinforced aluminum-based wire material according to claim 1, it is characterized in that, the specific steps are as follows: S1: Melt pure aluminum at 700-800°C in a melting furnace, then add K ₂ TiF ₄ and KBF ₄ mixed salt, copper grains, Al-Si master alloy, magnesium grains, zinc grains, and graphite powder in sequence, and squeeze The Al-Zr alloy pressed into 10mm wire is inserted into the aluminum melt at 10mm/min, and then the melt is purified; S2: Cool the aluminum melt prepared in S1 to 750°C for heat preservation, inject it into a continuous rheological extruder at 640°C-735°C, and prepare an aluminum-based wire rod with a diameter of 10-12mm; S3: The aluminum-based wire is drawn, and a unidirectional continuous pulse current is introduced into the wire through two flexible conductive fixtures. Firstly, a drawing is performed. During a drawing process, the average current is 40-50A, the pulse width is 30ms, the pulse interval is 10ms, and the frequency is 50Hz. The shrinkage rate of a drawing is 30%-40%. Then carry out the second drawing, in the second drawing process, the average current is 30-40A, the pulse width is 20ms, the pulse interval is 10ms, the pulse current is 50Hz, and the shrinkage rate of the second drawing is 40%- 50%, and then three times of drawing, the shrinkage rate of the three times of drawing is 70-80%, in the process of three times of drawing, the average current is 20-30A, the pulse width is 10ms, the pulse interval is 10ms, and the frequency is 50Hz pulse current, improve the elongation of the wire, and ensure the efficiency of wire drawing; the above-mentioned pulse current is unidirectional and in the same direction as the aluminum-based wire. S4: The wire rod obtained in step S3 is further subjected to other surface treatments such as scraping and winding, and then coiled to obtain a wire rod with a smooth surface, good wire feedability, and high performance. 3. according to the described method of claim 2, it is characterized in that, when fixing, adopt a kind of flexible conductive fixture, comprise the copper square shell that section is U-shaped, a plurality of copper square shells are arranged on the inner surface of U-shaped cavity Cylinder, a plurality of copper cylinders form a copper brush, the end face of the entire copper brush forms a semi-cylindrical cavity, two copper square shells are interlocked, and the wire is clamped in the semi-cylindrical cavity; the copper cylinder and the copper square shell are fixed and connected by springs, The size of the wire in the fixture shrinks into the copper square shell. 4. The method according to claim 3, wherein the copper square housing contains 140-200 copper brushes, 70-100 on one side.

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