High-strength aluminum alloy wire suitable for electric arc additive manufacturing and preparation method and application of high-strength aluminum alloy wire

Abstract

The invention provides a high-strength aluminum alloy wire suitable for electric arc additive manufacturing and a preparation method and application of the high-strength aluminum alloy wire. The high-strength aluminum alloy wire suitable for electric arc additive manufacturing is characterized by comprising, by mass, 4.0%-12% of Mg, 0.1%-0.8% of Mn, 0.05%-0.15% of Zn, 0.05%-0.6% of Sc, 0.025%-0.3% of Zr, 0.07%-1.36% of Ti, 0.03%-0.64% of B and the balance aluminum and inevitable impurities, the content of the impurities is lower than 0.1 wt.%, and Ti and B elements are introduced in an in-situ synthesis TiB2 ceramic seed crystal material mode. The high-strength aluminum alloy wire suitable for electric arc additive manufacturing is small in grain structure, high in strength, few in defect, uniform in structure and excellent in comprehensive performance, and can be widely applied to electric arc additive manufacturing of various parts.

Description

Technical Field

[0001] The present invention relates to aluminum alloy technology, and in particular to a high-strength aluminum alloy wire suitable for arc additive manufacturing, a preparation method thereof and uses thereof. Background Art

[0002] Additive Manufacturing (AM) originated from the rapid prototyping technology in the late 1980s. It is an advanced digital manufacturing technology that integrates materials, structures, and functions. Aluminum alloy has become a research hotspot in the field of additive manufacturing due to its low density, good elasticity, high specific stiffness and specific strength, excellent wear resistance and corrosion resistance, and good electrical and thermal conductivity. However, the high laser reflectivity and thermal conductivity of aluminum alloys are prone to cause problems such as thermal cracking, element burning and evaporation during laser and electron beam additive forming, resulting in a large number of pores and inclusions in the formed parts, and low forming stability and repeatability, which limits its application in engineering.

[0003] Wire and Arc Additive Manufacturing (WAAM) technology uses wire as raw material and forms dense metal parts through arc melting and accumulation layer by layer. This technology has the advantages of high forming efficiency, low equipment cost, and high material utilization. Compared with traditional subtractive processing, the WAAM system can reduce processing time by 40% to 60% and post-processing time by 15% to 20%. It is particularly suitable for manufacturing large and medium-complexity components, and has therefore received widespread attention from research institutions around the world.

[0004] The chemical composition and surface quality of aluminum alloy wire directly affect the material's thermophysical and mechanical properties. Only by using high-quality wire and combining it with a specific WAAM process can the formation of pores be effectively controlled and the mechanical properties be guaranteed. If there are defects in the quality of the wire inside and outside, the formed parts will have a large number of defects. In addition, the cyclic heating and cooling during the WAAM process will produce large internal tensile stresses, and the stability of the wire quality, diameter changes, cracks and scratches will directly lead to pore defects in the deposited material.

[0005] Due to the influence of tissue inheritance, the WAAM process has higher requirements for wire quality and mechanical properties than ordinary welding wire materials. The tensile strength of the ER5356 welding wire commonly used in the market is only about 350MPa. After WAAM forming, the strength drops to 250MPa, and the strength cannot be improved by heat treatment, which seriously limits the application of 5xxx series alloys in many fields. Therefore, it is imperative to develop new high-strength and high-quality aluminum alloy special wire suitable for WAAM, which will promote the further development of aluminum alloy WAAM technology. Summary of the invention

[0006] The purpose of the present invention is to propose a high-strength aluminum alloy wire suitable for arc additive manufacturing, in view of the problem that existing welding wires cannot meet the needs of arc additive manufacturing. The material has small grain structure, high strength, few defects, uniform structure, and excellent comprehensive performance, and can be widely used in arc additive manufacturing of various parts.

[0007] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0008] To achieve the above object, the technical solution adopted by the present invention is: a high-strength aluminum alloy wire suitable for arc additive manufacturing, comprising the following components in mass percentage: Mg: 4.0% to 12%, Mn: 0.1% to 0.8%, Zn: 0.05% to 0.15%, Sc: 0.05% to 0.6%, Zr: 0.025% to 0.3%, Ti: 0.07% to 1.36%, B: 0.03% to 0.64%, and the rest is aluminum and unavoidable impurities, the impurity content is less than 0.1wt.%, wherein Ti and B elements are in situ self-generated TiB 2 Ceramic seed material is introduced.

[0009] Furthermore, the high-strength aluminum alloy wire suitable for arc additive manufacturing includes the following components in mass percentage: Mg: 5% to 8%, Mn: 0.4% to 0.6%, Zn: 0.1%, Sc: 0.1% to 0.4%, Zr: 0.05% to 0.2%, Ti: 0.07% to 0.35%, B: 0.03% to 0.16%, and the rest is aluminum and unavoidable impurities, and the impurity content is less than 0.1wt.%, wherein Ti and B elements are in the form of in-situ self-generated TiB 2 Ceramic seed material is introduced.

[0010] Furthermore, the TiB 2 The content ratio of Ti and B elements in the ceramic seed material is 2.0 to 2.5.

[0011] Another object of the present invention is to disclose a method for preparing a high-strength aluminum alloy wire suitable for arc additive manufacturing, by rationally designing the chemical composition of the wire and introducing an appropriate amount of TiB into the melt. 2 Ceramic seeds and trace rare earth elements Sc realize a double heterostructure. In addition, ultrasonic melt treatment improves the work hardening rate and reduces defects. The process is simple and the prepared wire has the advantages of high surface quality, few defects and high strength.

[0012] Specifically, the method for preparing high-strength aluminum alloy wire suitable for arc additive manufacturing comprises the following steps:

[0013] Step (1) Melting and casting: a. Weigh each component according to the mass percentage, add pure Al ingot and pure Zn ingot into the melting furnace and heat until completely melted, add Al-Mn, Al-Sc and Al-Zr master alloys into the melt for alloying, stir evenly and keep the temperature at 750-780°C for 10-50 minutes; b. Cool the melt to 740-760°C and then add TiB 2 The ceramic seed material is remelted and diluted in a smelting furnace and kept warm for 5-30 minutes; c. After the melt temperature is reduced to 720-740°C, a pure Mg ingot is added and a layer of covering agent is evenly laid on the surface of the melt to prevent the Mg element from burning; d. After standing for 5-25 minutes, high-purity argon gas and refining agent are introduced into the melt for degassing and deslagging; e. The melt is subjected to ultrasonic treatment and then slag is removed, and an ingot is obtained after casting and cooling;

[0014] Step (2) homogenization annealing: homogenizing the ingot obtained after cooling to obtain a cast embryo;

[0015] Step (3) plastic processing: the obtained cast blank is then hot extruded or hot rolled to reduce the diameter of the cast blank to form a preliminary wire blank; the preliminary wire blank is subjected to intermediate annealing, peeling, drawing, stress relief annealing, scraping, and brightening treatment to obtain a high-strength aluminum alloy wire suitable for arc additive manufacturing, which is then stored in a vacuum.

[0016] Furthermore, the raw materials and covering agent in step (1) need to be dried before smelting, and the drying conditions are 200° C. to 250° C. for 20 to 30 minutes.

[0017] Furthermore, in step (1), the TiB 2 The ceramic seed material contains Ti and B elements, and the atomic ratio of Ti:B is controlled at 2.0-2.5.

[0018] Furthermore, in step (1), the TiB 2 Ceramic seed material is Al-6%TiB 2 .

[0019] Furthermore, in step (1), the TiB 2 The ceramic seed material can be industrially produced tons of TiB 2 Ceramic seed material.

[0020] Furthermore, the mass ratio of Sc:Zr in the melt of step (1) is 1.5 to 2.5.

[0021] Furthermore, the covering agent in step (1) comprises the following components in percentage by mass: 11% magnesium, 30% potassium, and 59% chlorine.

[0022] Furthermore, the ultrasonic tool head used in the ultrasonic treatment in step (1) is made of Si3 N 4 , the ultrasonic frequency is 15-20kHz, the power is 1.5-6kW, and the ultrasonic treatment time is 2-30 minutes.

[0023] Furthermore, the melting temperature in step (1) is 700-780°C, and the casting temperature is 700-730°C.

[0024] Furthermore, the homogenization annealing temperature in step (2) is 400-480° C., and the annealing time is 12-24 hours.

[0025] Furthermore, the stress relief annealing temperature in step (3) is 350-420° C., and the annealing time is 0.5-2 h.

[0026] Furthermore, the high-strength aluminum alloy wire suitable for arc additive manufacturing in step (3) has a diameter of 0.8 to 1.6 mm.

[0027] Another object of the present invention is to disclose a use of a high-strength aluminum alloy wire suitable for arc additive manufacturing in the field of arc additive manufacturing.

[0028] The high-strength aluminum alloy wire material suitable for arc additive manufacturing, the preparation method and use thereof of the present invention have the following advantages compared with the prior art:

[0029] 1) The high-strength aluminum alloy wire suitable for arc additive manufacturing prepared by the present invention generates a large amount of dispersed L1 during the hot working process and the arc additive manufacturing process by introducing trace amounts of Sc and Zr elements with optimized proportions. 2 -Al 3 (Sc, Zr) phase. This phase has the advantages of refining grains, increasing material strength, improving printing performance, and ensuring smoothness during 3D printing.

[0030] 2) The high-strength aluminum alloy wire suitable for arc additive manufacturing prepared by the present invention is prepared by introducing a trace amount of TiB 2 Ceramic seeds provide a large number of heterogeneous nucleation points for the material, further promoting grain refinement and effectively reducing element segregation during the casting process, thereby ensuring the quality of subsequent molding.

[0031] 3) The high-strength aluminum alloy wire suitable for arc additive manufacturing prepared by the present invention is treated with ultrasound in the melt, and the acoustic cavitation effect and acoustic streaming effect are used to make TiB 2 The ceramic seeds are evenly dispersed, agglomeration is reduced, casting defects are reduced, and ultimately a material with uniform structure and excellent mechanical properties is obtained.

[0032] 4) The high-strength aluminum alloy wire suitable for arc additive manufacturing prepared by the method of the present invention has a tensile strength of 420-540MPa, a yield strength of 380-420MPa, fine grains, good wire feeding performance and welding performance. Compared with existing aluminum alloy wires, this material has higher strength and better quality, and is particularly suitable for wire arc additive manufacturing.

[0033] In summary, the high-strength aluminum alloy wire material suitable for arc additive manufacturing in the present invention has small grain structure, high strength, few defects, uniform structure, and excellent comprehensive performance. It has good application prospects and large-scale promotion potential in the field of arc additive manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The Al-6%TiB added in Example 1 2 SEM image of ceramic seed material;

[0035] Figure 2 is TiB in Example 1 2 Size distribution of particles;

[0036] Figure 3 TEM image of the precipitation phase of the high-strength aluminum alloy wire manufactured by arc additive manufacturing in Example 4;

[0037] Figure 4 This is a size distribution diagram of the precipitated phase of the high-strength aluminum alloy wire manufactured by arc additive manufacturing in Example 4;

[0038] Figure 5 Partial physical picture of the wire material prepared in Example 2;

[0039] Figure 6 The room temperature tensile stress-strain curves of the aluminum alloy wires prepared in Example 2, Example 4 and the comparative example;

[0040] Figure 7 (a)-(d) are the printed parts of the high-strength aluminum alloy wires prepared in Examples 1-4 after arc additive manufacturing. DETAILED DESCRIPTION

[0041] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0042] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0043] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0044] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0045] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0046] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0047] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0048] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0049] Embodiment 1:

[0050] The present invention provides a high-strength aluminum alloy wire suitable for arc additive manufacturing, wherein the mass percentages of the elemental components are: Mg: 4.8%, Mn: 0.4%, Zn: 0.1%, Sc: 0.1%, Zr: 0.05%, Ti: 0.07%, B: 0.03%, and the rest are aluminum and unavoidable impurities, and the impurity content is less than 0.1wt.%.

[0051] The present invention provides a high-strength aluminum alloy wire suitable for arc additive manufacturing, and the preparation steps are as follows:

[0052] Step (1) Melting and Casting:

[0053] a. Weigh each component according to the mass percentage, add pure Al ingot and pure Zn ingot into the smelting furnace and heat until they are completely melted, add Al-Mn, Al-Sc and Al-Zr master alloys into the melt for alloying, stir evenly and keep the temperature at 770℃ for 30 minutes;

[0054] b. After the melt temperature drops to 750°C, the TiB2 ceramic seed material is remelted and diluted in a melting furnace and kept warm for 10 minutes;

[0055] c. After the melt temperature drops to 740°C, add pure Mg ingots and stir immediately, and evenly lay a layer of covering agent on the surface of the melt to prevent Mg element from burning;

[0056] d. After standing for 10 minutes, high-purity argon gas and refining agent are introduced into the melt to degas and remove slag;

[0057] e. The melt is subjected to ultrasonic treatment (frequency of 15 kHz, power of 2 kW) for 5 minutes, and then the slag is removed, and an ingot is obtained after casting and cooling;

[0058] Step (2) homogenization annealing: the ingot obtained after cooling in step (1) is subjected to homogenization annealing at 430° C. for 24 hours;

[0059] Step (3) plastic processing: the cast blank obtained in step (2) is hot extruded at 460° C. to reduce the diameter of the cast blank to 9.5 mm to form a preliminary wire blank; the preliminary wire blank is intermediate annealed at 410° C. for 1 hour, and after peeling, drawing, stress relief annealing, scraping, and brightening treatment, a high-strength aluminum alloy wire with a diameter of 1.2 mm suitable for arc additive manufacturing is obtained.

[0060] The mechanical properties test was carried out in accordance with the GB / T228.1-2021 "Metal Materials-Tensile Test" standard. The tensile strength of the wire was 360MPa, the yield strength was 285MPa, and the elongation was 6.2%.

[0061] Embodiment 2:

[0062] The present invention provides a high-strength aluminum alloy wire suitable for arc additive manufacturing, wherein the mass percentages of the elemental components are: Mg: 5.3%, Mn: 0.4%, Zn: 0.15%, Sc: 0.2%, Zr: 0.1%, Ti: 0.13%, B: 0.06%, and the rest are aluminum and unavoidable impurities, and the impurity content is less than 0.1wt.%.

[0063] The preparation method is the same as that in Example 1.

[0064] The mechanical properties test was carried out in accordance with the GB / T228.1-2021 "Metal Materials-Tensile Test" standard. The tensile strength of the wire was 478MPa, the yield strength was 370MPa, and the elongation was 6.6%.

[0065] Embodiment 3:

[0066] The present invention provides a high-strength aluminum alloy wire suitable for arc additive manufacturing, wherein the mass percentages of the elemental components are: Mg: 4.9%, Mn: 0.4%, Zn: 0.1%, Sc: 0.2%, Zr: 0.1%, Ti: 0.35%, B: 0.15%, and the rest are aluminum and unavoidable impurities, and the impurity content is less than 0.1wt.%.

[0067] The preparation method is the same as that in Example 1.

[0068] The mechanical properties test was carried out in accordance with the GB / T228.1-2021 "Metal Materials-Tensile Test" standard. The tensile strength of the wire was 493MPa, the yield strength was 397MPa, and the elongation was 7.2%.

[0069] Embodiment 4:

[0070] The present invention provides a high-strength aluminum alloy wire suitable for arc additive manufacturing, wherein the mass percentages of the elemental components are: Mg: 5.1%, Mn: 0.4%, Zn: 0.1%, Sc: 0.2%, Zr: 0.1%, Ti: 0.71%, B: 0.29%, and the rest are aluminum and unavoidable impurities, and the impurity content is less than 0.1wt.%.

[0071] The preparation method is the same as that in Example 1.

[0072] The mechanical properties test was carried out in accordance with the GB / T228.1-2021 "Metal Materials-Tensile Test" standard. The tensile strength of the wire was 521MPa, the yield strength was 414MPa, and the elongation was 4.3%.

[0073] The high-strength aluminum alloy wire suitable for arc additive manufacturing prepared in Examples 1-4 and the conventional commercially available aluminum alloy welding wire ER5356 (comparative example) were tested for mechanical properties according to GB / T228.1-2021 "Metallic Materials-Tensile Test", and the results are shown in Table 1.

[0074] Table 1 Comparison of mechanical properties of wire and printed samples at different element addition amounts

[0075]

[0076] The high-strength aluminum alloy wire suitable for arc additive manufacturing prepared by this method has the characteristics of good surface quality and few defects. In terms of mechanical properties, it can be seen from Table 1 that the wire obtained by this preparation method has good mechanical properties. The ultimate tensile strength of Example 3 can reach 493MPa, and the elongation is still not less than 7%, indicating that the strength and plasticity matching is good. The strength is increased by about 170MPa compared with the commercially produced ER5356 aluminum alloy wire, and the elongation is also improved. The wire prepared by the present invention also has good strength and plasticity after WAAM. This is because the Ti and B elements with a certain atomic ratio in the material provide TiB 2 Ceramic seed, TiB 2 The particles provide a large number of heterogeneous nucleation points to the matrix, so the grains are refined; on the other hand, the acoustic cavitation and acoustic streaming generated by the ultrasound in the melt will reduce the agglomeration of particles and make the particle distribution more uniform. In addition, Sc and Zr elements with a certain element ratio will also disperse and precipitate in the matrix L1 2 -Al 3 (Sc, Zr) phase can effectively pin the grain boundary and hinder dislocation movement to improve strength. Combined with the above analysis, the final strength of the product is greatly improved.

[0077] Figure 1 The Al-6%TiB added in Example 1 2 SEM image of ceramic seed material; Figure 2 is TiB in Example 1 2 Particle size distribution diagram; it can be seen that TiB 2 The particles are evenly distributed, in the shape of hexahedral plates, with a bimodal size, and are mostly composed of nano-scale particles less than 100nm and submicron-scale particles of 760nm.

[0078] Figure 3 TEM image of the precipitation phase of the high-strength aluminum alloy wire manufactured by arc additive manufacturing in Example 4; Figure 4 The size distribution diagram of the precipitated phase of the high-strength aluminum alloy wire manufactured by arc additive manufacturing in Example 4; the TEM image of the precipitated phase shows that L1 is dispersed and precipitated in the matrix 2 -Al 3 The (Sc, Zr) phase is distributed in a spherical shape with an average size of 7.8 nm. The fine and dispersed nanoscale precipitates can effectively pin the grain boundaries and hinder dislocation slip, playing the role of Orowan strengthening.

[0079] Figure 5 This is a partial physical picture of the wire material prepared in Example 2. It can be seen that the prepared wire material is relatively bright and has good surface quality; Figure 6 The room temperature tensile stress-strain curves of the aluminum alloy wires prepared in Example 2, Example 4 and the comparative example show that the wires prepared in the present invention have higher strength and plasticity.

[0080] Figure 7 (a)-(d) are the printed parts of the high-strength aluminum alloy wires prepared by arc additive manufacturing in Examples 1-4, respectively, which reflect good printing formability.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-strength aluminum alloy wire suitable for arc additive manufacturing, characterized in that: The invention comprises the following components in mass percentage: Mg: 4.0%-12%, Mn: 0.1%-0.8%, Zn: 0.05%-0.15%, Sc: 0.05%-0.6%, Zr: 0.025%-0.3%, Ti: 0.07%-1.36%, B: 0.03%-0.64%, and the rest are aluminum and unavoidable impurities, and the impurity content is less than 0.1wt.%, wherein Ti and B elements are introduced in the form of in-situ self-generated TiB2 ceramic seed material.

2. A method for preparing a high-strength aluminum alloy wire suitable for arc additive manufacturing as claimed in claim 1, characterized in that: The following steps are involved: Step (1) Melting and casting: a. Weigh each component according to the mass percentage, add pure Al ingot and Zn ingot into a smelting furnace and heat until completely melted, add Al-Mn, Al-Sc and Al-Zr intermediate alloys into the melt for alloying, stir evenly and keep warm; b. Remelt and dilute the TiB2 ceramic seed material in a smelting furnace and keep warm; c. Add pure Mg ingot into the melt and evenly lay a layer of covering agent on the surface of the melt to prevent Mg element from burning; d. After standing, introduce high-purity argon gas and refining agent into the melt for degassing and deslagging; e. Perform ultrasonic treatment on the melt and then remove the slag, and obtain an ingot after casting and cooling; Step (2) homogenization annealing: homogenizing the ingot obtained after cooling to obtain a cast embryo; Step (3) plastic processing: the obtained cast blank is then hot extruded or hot rolled to reduce the diameter of the cast blank to form a preliminary wire blank; the preliminary wire blank is subjected to intermediate annealing, peeling, drawing, stress relief annealing, scraping, and brightening treatment to obtain a high-strength aluminum alloy wire suitable for arc additive manufacturing.

3. The preparation method according to claim 2, characterized in that: In step (1), the raw materials and covering agent must be dried before smelting, and the drying conditions are 200° C. to 250° C. for 20 to 30 minutes.

4. The preparation method according to claim 2, characterized in that: The TiB2 ceramic seed material in step (1) contains Ti and B elements, and the atomic ratio of Ti:B is controlled at 2.0 to 2.

5.

5. The preparation method according to claim 2, characterized in that: The mass ratio of Sc:Zr in the melt of step (1) is 1.5 to 2.

5.

6. The preparation method according to claim 2, characterized in that: The ultrasonic tool head used in the ultrasonic treatment in step (1) is made of Si3N4, the ultrasonic frequency is 15-20kHz, and the power is 1.5-6kW.

7. The preparation method according to claim 2, characterized in that: The melting temperature of step (1) is 700-780°C, and the casting temperature is 700-730°C.

8. The preparation method according to claim 2, characterized in that: The homogenization annealing temperature in step (2) is 400-480° C., and the annealing time is 12-24 hours.

9. The preparation method according to claim 2, characterized in that: The stress relief annealing temperature in step (3) is 350-420° C., and the annealing time is 0.5-2 h.

10. Use of the high-strength aluminum alloy wire suitable for arc additive manufacturing according to claim 1 in the field of arc additive manufacturing.

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