Zr / TiC composite reinforced 7075 aluminum alloy wire as well as preparation method and application thereof

Abstract

The invention discloses a Zr / TiC composite reinforced 7075 aluminum alloy wire as well as a preparation method and application thereof, and the aluminum alloy wire comprises the following chemical components in percentage by mass: 5.8%-6.1% of Zn, 2.1%-2.4% of Mg, 1.4%-1.7% of Cu, 0.6%-2.0% of Zr, 0.3%-2.8% of Ti, less than or equal to 0.15% of Cr, less than or equal to 0.15% of Fe, 0.1%-0.4% of C and the balance of Al and other inevitable impurities. The preparation method comprises the following steps: smelting an aluminum alloy ingot by using a pure Al ingot, pure Zn particles, pure Mg particles, pure Cu particles, an Al-Zr intermediate alloy and an Al-Ti-C intermediate alloy, and carrying out homogenization, hot extrusion and drawing reducing deformation processing on the ingot to obtain the wire. An electric arc additive structural part prepared from the aluminum alloy wire is stable in quality and good in mechanical property.

Description

Technical Field

[0001] The present invention relates to an aluminum alloy wire material and a preparation method and application thereof, and in particular to a Zr / TiC composite-reinforced 7075 aluminum alloy wire material and a preparation method and application thereof. Background Art

[0002] Compared to traditional subtractive manufacturing using mechanical cutting and mold-based manufacturing, additive manufacturing offers significant advantages in the efficient production of precision and complex structural parts. Arc-fuse additive manufacturing, which uses wire and arc as its energy source, offers advantages over laser and electron beam additive manufacturing technologies, such as lower costs, higher material utilization, and higher forming efficiency. This technology holds great promise for the production of integrated, large-scale structural parts.

[0003] With its high specific strength and good corrosion resistance, 7075 aluminum alloy has great potential in achieving the goal of "enhancing and reducing weight" for aerospace structural parts. Compared with traditional casting, forging, and milling processes, arc additive manufacturing of 7075 aluminum alloy has gradually demonstrated advantages such as short process flow, high economic benefits, and the ability to achieve near-net-shape forming. It is suitable for the production and preparation of large aspect ratio structural parts such as rocket cabins and connecting end frames. However, the current arc additive manufacturing of 7075 aluminum alloy still has the following problems: First, due to the complex composition of alloying elements, there is a small amount of 7075 aluminum alloy wire used for arc additive manufacturing, and the uniformity of the wire is generally poor, resulting in unstable quality of the prepared structural parts; second, 7075 aluminum alloy has a high sensitivity to hot cracking, and defects such as pores and coarse structure are very likely to appear during arc additive manufacturing, resulting in insufficient mechanical properties of the material. These problems have seriously restricted the application of arc additive manufacturing of 7075 aluminum alloy structural parts. Summary of the Invention

[0004] Purpose of the invention: In order to overcome the deficiencies in the prior art, the purpose of the present invention is to provide a Zr / TiC composite-reinforced 7075 aluminum alloy wire with good uniformity and few defects such as porosity and inclusions. Another purpose of the present invention is to provide a method for preparing the Zr / TiC composite-reinforced 7075 aluminum alloy wire with high production efficiency. A further purpose of the present invention is to provide an application of the Zr / TiC composite-reinforced 7075 aluminum alloy wire in arc additive manufacturing.

[0005] Technical solution: The Zr / TiC composite-reinforced 7075 aluminum alloy wire described in the present invention has the following chemical compositions, calculated by mass percentage: Zn: 5.8% to 6.1%, Mg: 2.1% to 2.4%, Cu: 1.4% to 1.7%, Zr: 0.6% to 2.0%, Ti: 0.3% to 2.8%, Cr: ≤0.15%, Fe: ≤0.15%, C: 0.1% to 0.4%, and the balance is Al and other inevitable impurities.

[0006] Furthermore, a diameter of 1-2mm facilitates additive manufacturing using welding methods such as cold metal transfer, offering a wide range of applications and meeting the current wire diameter requirements for arc additive manufacturing. Diameters greater than 2mm are incompatible with current mainstream welding machines, while diameters less than 1mm increase processing costs. Furthermore, smaller wire diameters make surface quality more difficult to control, resulting in reduced wire feeding stability during deposition.

[0007] The preparation method of the Zr / TiC composite-reinforced 7075 aluminum alloy wire disclosed by the present invention comprises the following steps: using pure Al ingots, pure Zn particles, pure Mg particles, pure Cu particles, Al-Zr master alloys, and Al-Ti-C master alloys to smelt aluminum alloy ingots; and subjecting the aluminum alloy ingots to homogenization, hot extrusion, and drawing and reducing deformation to obtain Zr / TiC composite-reinforced 7075 aluminum alloy wires.

[0008] Furthermore, the mass ratio of the pure Al ingot, the pure Zn particles, the pure Mg particles, the pure Cu particles, the Al-Zr master alloy, and the Al-Ti-C master alloy is 20:2:1:1:3:4-6.

[0009] Furthermore, the mass percentage of Zr in the Al-Zr master alloy is 8.13% to 11.21%, and the remainder is Al and other inevitable impurities.

[0010] Furthermore, the mass percentage of Ti in the Al-Ti-C master alloy is 1.61% to 5.11%, the mass percentage of C is 0.34% to 1.5%, and the rest is Al and other inevitable impurities.

[0011] Furthermore, the extrusion speed of the hot extrusion treatment is 1 to 3 m / min, and the extrusion ratio is less than 10.

[0012] Furthermore, the deformation amount of each drawing and reducing pass does not exceed 50%.

[0013] Furthermore, during the drawing and reducing deformation process, an annealing treatment is performed at a temperature of 350 to 450° C. for 1 to 3 hours.

[0014] The invention describes a Zr / TiC composite-reinforced 7075 aluminum alloy wire for arc additive manufacturing. This wire is deposited using a cold metal transfer welding method with a current of 70-160A, a voltage of 6-18V, a wire feed speed of 3-10m / min, a deposition rate of 5-15mm / s, and high-purity argon as the shielding gas at a flow rate of 15-25L / min. The resulting deposited structural components exhibit no thermal cracks, minimal porosity, and a refined and uniform microstructure. After solution treatment at 475°C for 2.5h and aging at 120°C for 24h, the material exhibits excellent overall performance.

[0015] Preparation principle: Due to the inherent layer-by-layer deposition characteristics and dynamic thermal cycling effects of the arc additive process, the arc additive microstructure of traditional 7075 aluminum alloy is mainly coarse cellular dendrites, and is often accompanied by defects such as pores and thermal cracks between the deposited layers, which significantly deteriorates the vertical performance of the deposited structural parts. When the Zr element is introduced, during the rapid non-equilibrium solidification stage of the molten pool, the solute Zr atoms in the melt can first form the Al3Zr phase with a higher melting point from the liquid phase. The Al3Zr phase has a low lattice mismatch with the α-Al matrix and can become an effective heterogeneous nucleation site for α-Al grains, transforming the alloy microstructure from coarse cellular dendrites to fine and uniform equiaxed crystals, thereby achieving the purpose of significantly refining the alloy microstructure.

[0016] Al-Ti-C master alloys can also effectively introduce micro- and nano-scale TiC ceramic particles. TiC particles have a high melting point and good thermal stability, and generally do not change during the arc additive process. On the one hand, high-melting-point TiC particles can serve as nucleation sites for the Al3Zr phase, effectively reducing the nucleation barrier of the new Al3Zr phase, thereby increasing the density of the heterogeneous nucleation substrate in the melt. On the other hand, TiC particles themselves have good interface matching with the α-Al matrix on low-index surfaces and are not prone to interfacial reactions with the α-Al matrix. They can also directly act as heterogeneous nucleation sites, exerting a composite strengthening effect with the Al3Zr phase, further refining the microstructure of the deposited alloy. In addition, TiC particles can promote the diffuse distribution of pores during molten pool convection, effectively suppressing pore defects in the alloy and reducing the anisotropy of material properties.

[0017] Taking into account the composite strengthening effect of the Al3Zr phase and TiC particles, while effectively suppressing pores and thermal crack defects and significantly refining the alloy structure, the high-strength aluminum alloy wire for arc additive manufacturing described in the present invention can be guaranteed to meet the needs of efficient preparation of large aerospace structural parts.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0019] 1. The preparation process of Zr / TiC composite reinforced 7075 aluminum alloy wire is simple, the wire has good uniformity, few defects and inclusions, and the TiC particles are evenly distributed in the wire. The arc additive structure prepared by it has stable quality and good mechanical properties;

[0020] 2. For Zr / TiC composite-reinforced 7075 aluminum alloy wire used in arc additive manufacturing, during the deposition manufacturing process, on the one hand, some Al3Zr can be formed by relying on micro-nano TiC particles, increasing the nucleation base density in the matrix and greatly improving the nucleation efficiency of micro-nano TiC particles as nucleation points. On the other hand, under the conditions of the rapidly cooling molten pool, some solute element Zr does not have time to diffuse and remains in the deposited structural part in the form of solid solution. The subsequent gradient heat treatment system can induce the precipitation of Al3Zr precipitate phase, thereby improving the dispersion strengthening effect.

[0021] 3. Micro-nano TiC particles are directly synthesized in situ and dispersed throughout the alloy. Compared to previously reported methods, this method eliminates the need for pre-prepared particle-reinforced alloy powders, resulting in higher material utilization, production efficiency, and economic benefits. Because the ingots are cast in a water-cooled steel mold, solute Zr segregation to form a coarse Al3Zr phase is avoided, instead existing in a solid solution. This fully ensures the uniformity of the aluminum alloy wire and makes it suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a microstructure diagram of the aluminum alloy wire prepared in Example 1 of the present invention;

[0023] Figure 2 1 is a microstructure diagram of a deposited structure prepared in Application Example 1 of the present invention;

[0024] Figure 3 is a microstructure diagram of the deposited structure prepared in Comparative Example 1;

[0025] Figure 4 is a microstructure diagram of the deposited structure prepared in Comparative Example 2;

[0026] Figure 5 is a microstructure diagram of the deposited structure prepared in Comparative Example 3;

[0027] Figure 6 is a microstructure diagram of the deposited structure prepared in Comparative Example 4;

[0028] Figure 7 This is a microstructure diagram of the deposited structure prepared in Comparative Example 5. DETAILED DESCRIPTION

[0029] Unless otherwise specified, the materials and reagents used in the following examples are commercially available. Experimental methods not specified in the examples were generally performed under conventional conditions or those recommended by the manufacturer. Al-Zr master alloy was purchased from Northeast Nonferrous Metals Company, model Al-10Zr. Al-Ti-C master alloy was purchased from Shanghai Xingxin Trading Co., Ltd., model Al-Ti1-C0.2 and Al-Ti5-C1. Aluminum alloy refining agents were purchased from Jiangsu Hetuo Aluminum Wire Co., Ltd.

[0030] Example 1

[0031] A Zr / TiC composite reinforced 7075 aluminum alloy wire has the following chemical compositions by mass percentage: Zn: 5.83%, Mg: 2.17%, Cu: 1.69%, Zr: 1.10%, Ti: 0.32%, Cr: 0.15%, Fe: 0.14%, C: 0.31%, other single impurity elements: ≤0.05%, and the remainder is Al.

[0032] The preparation method of Zr / TiC composite reinforced 7075 aluminum alloy wire comprises the following steps:

[0033] (1) The raw materials were prepared according to the designed composition: 10 kg of pure Al ingots, 1 kg of pure Zn pellets, 0.4 kg of pure Mg pellets, 0.3 kg of pure Cu pellets, 1.5 kg of Al-Zr master alloy, and 2 kg of Al-Ti-C master alloy. The raw materials were cleaned of surface oil, organic solvents, and sand from cutting with anhydrous ethanol and then kept in a vacuum oven at 100°C for 30 minutes. The composition of the Al-Zr master alloy by mass percentage is: Zr: 11.21%, other individual impurity elements: ≤0.05%, and the remainder is Al. The composition of the Al-Ti-C master alloy by mass percentage is: Ti: 5.11%, C: 1.5%, other individual impurity elements: ≤0.05%, and the remainder is Al.

[0034] (2) After preheating the pure Al ingot to 680°C in a pit melting furnace, it was transferred to an electromagnetic stirring melting furnace and heated to 740°C. Zn, Mg, and Cu particles were added. After complete melting, the temperature was continued to rise to 830°C. Al-Zr master alloy and Al-Ti-C master alloy were added according to the designed composition, and the melt state was observed.

[0035] (3) After the raw materials are completely melted, the temperature is lowered to 740°C, and a refining agent is added for stirring, degassing, and slagging. The temperature is then raised to 880°C for degassing again, and then casting is performed using a water-cooled steel mold.

[0036] (4) After the ingot was homogenized at 480°C for 12 h, it was hot extruded at an extrusion speed of 2 m / min and an extrusion ratio of 8.

[0037] (5) The extruded coil is subjected to multiple drawing and annealing processes, with each drawing and annealing process having a diameter reduction of 30%, an annealing temperature of 420°C, and a time of 2 h. Finally, a Zr / TiC composite-reinforced 7075 aluminum alloy wire with a diameter of 1.2 mm is obtained by scraping.

[0038] like Figure 1 The average size of the second phase in the prepared Zr / TiC composite-reinforced 7075 aluminum alloy wire is 5 μm, the TiC particles are evenly distributed, and there are no obvious defects such as pores and coarse inclusions, with good uniformity.

[0039] Application Example 1

[0040] The aluminum alloy wire obtained in Example 1 was deposited and manufactured using a cold metal transfer process. The preferred process parameters were: current 150A, voltage 14.6V, wire feed speed 8.6m / min, deposition speed 10mm / s, shielding gas high-purity argon, gas flow rate 20L / min. The dimensions of the deposited structure prepared were: height 60mm, width 20mm, length 200mm. Figure 2 As shown, the prepared deposited structural parts have uniform structure, mainly small equiaxed crystals with an average grain size of about 12μm. The internal pore size is generally below 20μm and is diffusely distributed in the matrix, without deposition thermal crack defects.

[0041] Example 2

[0042] A Zr / TiC composite reinforced 7075 aluminum alloy wire has the following chemical compositions by mass percentage: Zn: 5.8%, Mg: 2.1%, Cu: 1.4%, Zr: 0.6%, Ti: 0.3%, Cr: 0.14%, Fe: 0.1%, C: 0.1%, other single impurity elements: ≤0.05%, and the remainder is Al.

[0043] The preparation method of Zr / TiC composite reinforced 7075 aluminum alloy wire comprises the following steps:

[0044] (1) The raw materials were prepared according to the designed composition. 10 kg of pure Al ingots, 1.5 kg of pure Zn pellets, 0.5 kg of pure Mg pellets, 0.3 kg of pure Cu pellets, 2 kg of Al-Zr master alloy, and 5 kg of Al-Ti-C master alloy were cleaned of surface oil, organic solvents, and sand from cutting with anhydrous ethanol and then kept in a vacuum oven at 100°C for 20 minutes. The composition of the Al-Zr master alloy, calculated by mass percentage, was as follows: Zr: 8.13%, other individual impurity elements: ≤0.05%, and the remainder was Al. The composition of the Al-Ti-C master alloy, calculated by mass percentage, was as follows: Ti: 1.61%, C: 0.34%, other individual impurity elements: ≤0.05%, and the remainder was Al.

[0045] (2) After preheating the pure Al ingot to 660°C in a pit-type melting furnace, it was transferred to an electromagnetic stirring melting furnace and heated to 730°C at the same time. Zn, Mg, and Cu particles were added. After complete melting, the temperature was continued to rise to 800°C. Al-Zr master alloy and Al-Ti-C master alloy were added according to the designed composition, and the melt state was observed.

[0046] (3) After the raw materials are completely melted, the temperature is lowered to 730°C, and a refining agent is added for stirring, degassing, and slagging. The temperature is then raised to 850°C for degassing again, and then casting is performed using a water-cooled steel mold.

[0047] (4) After the ingot was homogenized at 480°C for 12 h, it was hot extruded at an extrusion speed of 1 m / min and an extrusion ratio of 8.

[0048] (5) The extruded coil is subjected to multiple drawing and annealing processes, with each drawing and annealing process being 50% in diameter, the annealing temperature being 350°C, and the time being 3 h. Finally, Zr / TiC composite-reinforced 7075 aluminum alloy wire with a diameter of 1 mm is obtained by scraping.

[0049] Example 3

[0050] A Zr / TiC composite reinforced 7075 aluminum alloy wire has the following chemical compositions by mass percentage: Zn: 6.1%, Mg: 2.4%, Cu: 1.7%, Zr: 2.0%, Ti: 2.8%, Cr: 0.12%, Fe: 0.12%, C: 0.4%, other single impurity elements: ≤0.05%, and the remainder is Al.

[0051] The preparation method of Zr / TiC composite reinforced 7075 aluminum alloy wire comprises the following steps:

[0052] (1) The raw materials were prepared according to the designed composition. 0 kg of pure Al ingot, 4 kg of pure Zn pellets, 1.6 kg of pure Mg pellets, 1.2 kg of pure Cu pellets, 15 kg of Al-Zr master alloy, and 35 kg of Al-Ti-C master alloy were cleaned of surface oil, organic solvents, and sand from cutting with anhydrous ethanol and then kept in a vacuum oven at 100°C for 40 minutes. The composition of the Al-Zr master alloy, calculated by mass percentage, was as follows: Zr: 10.34%, other individual impurity elements: ≤0.05%, and the remainder was Al. The composition of the Al-Ti-C master alloy, calculated by mass percentage, was as follows: Ti: 5.07%, C: 1.00%, other individual impurity elements: ≤0.05%, and the remainder was Al.

[0053] (2) After preheating the pure Al ingot to 700 °C in a pit melting furnace, transfer it to an electromagnetic stirring melting furnace, and simultaneously raise the temperature to 750 °C and add Zn, Mg, and Cu particles. After it is completely melted, continue to raise the temperature to 850 °C, add Al-Zr master alloy and Al-Ti-C master alloy according to the designed composition, and observe the melt state.

[0054] (3) After the raw materials are completely melted, the temperature is lowered to 750°C, and a refining agent is added for stirring, degassing, and slagging. The temperature is then raised to 900°C for degassing again, and then casting is performed using a water-cooled steel mold.

[0055] (4) After the ingot was homogenized at 480°C for 12 h, it was hot extruded at an extrusion speed of 3 m / min and an extrusion ratio of 9.

[0056] (5) The extruded coil is subjected to multiple drawing and annealing processes, with each drawing and annealing process being 40% in diameter, the annealing temperature being 450°C, and the time being 1 h. Finally, Zr / TiC composite-reinforced 7075 aluminum alloy wire with a diameter of 2 mm is obtained by scraping.

[0057] Comparative Example 1

[0058] This comparative example was prepared using the same methods as Example 1, except for the following: The aluminum alloy wire composition in Comparative Example 1, calculated by mass percentage, was: Zn: 5.86%, Mg: 2.32%, Cu: 1.48%, Ti: 0.27%, Cr: 0.15%, Fe: 0.15%, C: 0.23%, with the remainder being Al. Compared to Example 1, Comparative Example 1 did not contain the element Zr.

[0059] The aluminum alloy wire prepared in Comparative Example 1 and the arc additive method of Application Example 1 were used for deposition manufacturing. The surface of the deposited structure prepared had a small amount of thermal cracks, and the structure had obvious alternating distribution characteristics of coarse grained areas and fine grained areas along the vertical direction. There were certain pore defects between the deposited layers, and the average grain size was about 26μm. Figure 3shown.

[0060] Comparative Example 2

[0061] This comparative example was prepared using the same method as Example 1, with the difference being the aluminum alloy wire composition: Calculated by mass percentage, the aluminum alloy wire in Comparative Example 2 contained: Zn: 5.87%, Mg: 2.46%, Cu: 1.83%, Zr: 1.09%, Cr: 0.15%, Fe: 0.15%, with the remainder being Al. Compared to Example 1, Comparative Example 2 did not contain TiC particles.

[0062] The aluminum alloy wire prepared in Comparative Example 2 and the arc additive method of Application Example 1 were used for deposition manufacturing. Although the structure of the deposited structure prepared was refined compared with that of Comparative Example 1, there was still a certain gap compared with Example 1. At the same time, there were obvious pore defects in the structure, and the average grain size was about 19 μm. Figure 4 shown.

[0063] Comparative Example 3

[0064] This comparative example was prepared using the same method as Example 1, differing in the aluminum alloy wire composition. Calculated by mass percentage, the aluminum alloy wire in Comparative Example 3 contained: 5.77% Zn, 2.19% Mg, 1.74% Cu, 0.61% Zr, 0.15% Cr, and 0.15% Fe, with the remainder being Al. Compared to Example 1, Comparative Example 3 contained no TiC particles and had a lower Zr content.

[0065] The aluminum alloy wire prepared in Comparative Example 3 and the arc additive method of Application Example 1 were used for deposition manufacturing. Figure 5 As shown, it can be found that when the Zr element content is insufficient, the microstructure refinement effect of the alloy is not obvious, which is similar to Comparative Example 1.

[0066] Comparative Example 4

[0067] This comparative example was prepared using the same method as Example 1, differing in the aluminum alloy wire composition. Calculated by mass percentage, the aluminum alloy wire in Comparative Example 4 contained: Zn: 5.74%, Mg: 2.32%, Cu: 1.67%, Zr: 1.92%, Cr: 0.15%, Fe: 0.15%, with the remainder being Al. Compared to Example 1, Comparative Example 4 contained no TiC particles and had a higher Zr content.

[0068] The aluminum alloy wire prepared in Comparative Example 4 and the arc additive method of Application Example 1 were used for deposition manufacturing. It can be found that when the Zr element content is too high, the microstructure refinement effect is not significantly improved compared with Example 1 and Comparative Example 2, but serious pore defects appear in the microstructure, such as Figure 6 shown.

[0069] Comparative Example 5

[0070] This comparative example was prepared using the same method as Example 1, differing in the aluminum alloy wire composition. Calculated by mass percentage, the aluminum alloy wire in Comparative Example 5 contained: Zn: 5.80%, Mg: 2.28%, Cu: 1.56%, Ti: 1.21%, Cr: 0.15%, Fe: 0.15%, C: 0.37%, with the remainder being Al. Compared to Example 1, Comparative Example 5 contained no Zr and had a higher TiC content.

[0071] The aluminum alloy wire prepared in Comparative Example 5 and the arc additive method of Application Example 1 were used for deposition manufacturing. Figure 7 It can be found that the microstructure refinement effect in Comparative Example 5 is acceptable, but due to the excessively high TiC content in the wire, severe segregation occurs near the grain boundaries, resulting in significant grain boundary weakening, which directly leads to insufficient plasticity of the material.

[0072] Table 1 Composition of aluminum alloy wires used in Example 1 and Comparative Examples 1-5 and properties of the structural parts obtained by arc additive manufacturing after heat treatment

[0073] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Zn 5.83 5.86 5.87 5.77 5.74 5.80 Mg 2.17 2.32 2.46 2.19 2.32 2.28 Cu 1.69 1.48 1.83 1.74 1.67 1.56 Zr 1.10 / 1.09 0.61 1.92 / Ti 0.32 0.27 / / / 1.21 C 0.31 0.23 / / / 0.37 Fe 0.14 0.15 0.15 0.15 0.15 0.15 Cr 0.15 0.15 0.15 0.15 0.15 0.15 Al margin margin margin margin margin margin Yield strength (MPa) 514 364 459 442 401 422 Tensile strength (MPa) 551 453 508 481 457 481 Elongation at break (%) 5.9 3.9 4.7 4.2 3.9 4.2

[0074] As shown in Table 1, the aluminum alloy wires obtained in Example 1 and Comparative Examples 1-5 were subjected to arc additive manufacturing (AM). Tensile properties of the structural components obtained after the same heat treatment were then tested according to GB / T 228.1-2010. The results show that the aluminum alloy wires in Example 1, after AM, produced components with yield strength, tensile strength, and elongation at break of 514 MPa, 551 MPa, and 5.9%, respectively. This is due to the significant microstructure refinement and effective elimination of pore defects in the deposited material. However, due to the lack of Zr in the wires of Comparative Example 1 and the low Zr content in the wires of Comparative Example 3, the grain refinement in the deposited material was insufficient, resulting in a performance ceiling. Although the Zr content in the wires of Comparative Example 2 was similar to that of Example 1, the mechanical properties did not exhibit significant advantages due to the ineffective elimination of pore defects in the deposited material and the lack of microstructure refinement compared to Example 1. In Comparative Example 4, the Zr content is too high, resulting in serious porosity defects in the deposited material structure and obvious performance deterioration; in Comparative Example 5, the TiC content is too high, causing the TiC particles in the deposited material to generally aggregate near the grain boundaries, deteriorating the plasticity of the material.

[0075] Among the above embodiments, embodiment 1 is the optimal embodiment with the best comprehensive performance.

Claims

1. A Zr / TiC composite reinforced 7075 aluminum alloy wire, characterized by: Calculated by mass percentage, its chemical composition is: Zn: 5.8%~6.1%, Mg: 2.1%~2.4%, Cu: 1.4%~1.7%, Zr: 0.6%~2.0%, Ti: 0.3%~2.8%, Cr: ≤0.15%, Fe: ≤0.15%, C: 0.1%~0.4%, and the balance is Al and other inevitable impurities.

2. The Zr / TiC composite-reinforced 7075 aluminum alloy wire according to claim 1, characterized in that: The diameter is 1 to 2 mm.

3. A method for preparing the Zr / TiC composite reinforced 7075 aluminum alloy wire according to claim 1, characterized in that: The following steps are involved: Pure Al ingots, pure Zn particles, pure Mg particles, pure Cu particles, Al-Zr master alloy, and Al-Ti-C master alloy are used to melt aluminum alloy ingots. The aluminum alloy ingots are subjected to homogenization, hot extrusion, and drawing and reducing deformation to obtain Zr / TiC composite-reinforced 7075 aluminum alloy wires.

4. The method for preparing the Zr / TiC composite-reinforced 7075 aluminum alloy wire according to claim 3, wherein: The mass ratio of the pure Al ingot, pure Zn particles, pure Mg particles, pure Cu particles, Al-Zr master alloy, and Al-Ti-C master alloy is 20:2:1:1:3:4-6.

5. The method for preparing the Zr / TiC composite-reinforced 7075 aluminum alloy wire according to claim 3, wherein: The mass percentage of Zr in the Al-Zr master alloy is 8.13% to 11.21%, and the rest is Al and other inevitable impurities.

6. The method for preparing the Zr / TiC composite-reinforced 7075 aluminum alloy wire according to claim 3, wherein: The mass percentage of Ti in the Al-Ti-C master alloy is 1.61% to 5.11%, the mass percentage of C is 0.34% to 1.5%, and the rest is Al and other inevitable impurities.

7. The method for preparing the Zr / TiC composite-reinforced 7075 aluminum alloy wire according to claim 3, wherein: The extrusion speed of the hot extrusion process is 1 to 3 m / min, and the extrusion ratio is less than 10.

8. The method for preparing the Zr / TiC composite-reinforced 7075 aluminum alloy wire according to claim 3, wherein: During the drawing and reducing deformation, the deformation amount of each pass does not exceed 50%.

9. The method for preparing the Zr / TiC composite-reinforced 7075 aluminum alloy wire according to claim 3, wherein: During the drawing and diameter-reducing deformation process, an annealing treatment is performed at a temperature of 350 to 450° C. for 1 to 3 hours.

10. The use of a Zr / TiC composite reinforced 7075 aluminum alloy wire in arc additive manufacturing according to claim 1, characterized in that: Deposition manufacturing is carried out by cold metal transfer welding method, with a current of 70 to 160A, a voltage of 6 to 18V, a wire feeding speed of 3 to 10m / min, a deposition speed of 5 to 15mm / s, a shielding gas of high-purity argon, and a gas flow rate of 15 to 25L / min.

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