A preparation method of AlSi10Mg alloy wire for additive manufacturing

Abstract

The present invention discloses a method for preparing an AlSi10Mg alloy wire for additive manufacturing, belonging to the technical field of electric arc additive manufacturing. The present invention prepares an alloy wire through processes such as alloy smelting, gas-assisted continuous casting and extrusion, drawing, annealing, and peeling, wherein the main alloy element contents are Si: 9.0-11%, and Mg: 0.3-0.6%. The principle of the present invention is to use gas-assisted continuous casting and extrusion to improve the plasticity of the alloy, use drawing deformation + annealing to reduce the diameter of the alloy round rod, and use peeling to remove pollutants on the surface of the wire, and finally obtain an AlSi10Mg alloy wire that can be used for additive manufacturing; the production method proposed by the present invention has the advantages of short process, low cost, simple operation, etc., and is convenient for industrial application.

Description

Technical Field

[0001] The invention relates to a method for preparing an AlSi10Mg alloy wire for additive manufacturing, and belongs to the technical field of electric arc additive manufacturing. Background Art

[0002] AlSi10Mg alloy is a hypoeutectic aluminum-silicon alloy with a narrow solidification range and good fluidity. It has excellent weldability, formability, and heat resistance. Its isothermal solidification characteristics can reduce the cracking tendency of castings, and has attracted widespread attention in the field of additive manufacturing. Currently, the application of this alloy in additive manufacturing mainly uses metal powder as raw material, and adopts selective laser melting (SLM) and other technologies to form complex structural parts. Research has shown that the density of such products can reach over 99.90%, and they exhibit excellent mechanical properties.

[0003] Compared to technologies like SLM, which use metal powder as raw materials, wire and arc additive manufacturing (WAAM), which uses alloy wire as raw materials, offers advantages such as high forming efficiency, low manufacturing costs, and the ability to expand the size of the product without spatial constraints. This has attracted significant interest from numerous research institutions. However, it is worth noting that the needle-like or plate-like eutectic silicon phases formed in the traditional casting process of AlSi10Mg alloys can severely fracture the aluminum matrix and reduce plasticity, making the preparation of alloy wire extremely difficult. This has hindered the large-scale application of this alloy in the production of large aluminum alloy components using WAAM. Summary of the Invention

[0004] The present invention aims to provide a method for preparing AlSi10Mg alloy wire for additive manufacturing, aiming to broaden the application of AlSi10Mg alloy in the field of additive manufacturing, and specifically comprises the following steps:

[0005] (1) Material preparation: According to the mass percentage of Si: 9-11%, Mg: 0.3-0.6%; the balance is Al, weigh the aluminum-silicon master alloy, pure magnesium ingot, and aluminum ingot respectively.

[0006] (2) Melting: Place the aluminum-silicon master alloy and aluminum ingot into a furnace for melting. When the melt temperature reaches 750-800°C, keep it warm for 30-60 minutes, add the magnesium ingot, and stir until the mixture is uniform. During the stirring process, the melt temperature is maintained at 750-800°C. Finally, keep it warm at 700-750°C for 30-60 minutes to complete the melting.

[0007] (3) Preparation of AlSi10Mg alloy rod by gas-assisted continuous casting and extrusion: The smelted metal melt flows into the extrusion wheel groove from the preheated funnel located above the extrusion wheel. Under the action of inert gas, the melt spreads out close to the wall of the extrusion wheel groove and begins to solidify. When the solidifying billet encounters a blockage, it begins to accumulate and gradually transfers into the die cavity, and is finally extruded from the die hole to form an alloy rod.

[0008] (4) The alloy rod obtained in step (3) is cold drawn to obtain a wire material, and annealing is required when the cumulative deformation is 20%-50%.

[0009] (5) The wire material in step (4) is peeled to obtain an AlSi10Mg alloy wire with a diameter of 0.8-1.5 mm.

[0010] Preferably, the diameter of the funnel in step (3) of the present invention is 2-4 mm, and the funnel needs to be heated to 850-880° C. before pouring the alloy melt.

[0011] Preferably, the inert gas in step (3) of the present invention is nitrogen or argon, and the gas pressure is 0.2-0.4 MPa.

[0012] Preferably, the speed of the extrusion wheel in step (3) of the present invention is 5-15 rpm.

[0013] Preferably, in step (3) of the present invention, the preheating temperature of the extrusion die cavity is 350-450° C., and the die hole diameter is 8-10 mm.

[0014] In step (4) of the present invention, the drawing process requires 3-4 annealings, the annealing temperature is 150-520° C., and the annealing time is 0.25-2 h.

[0015] Preferably, the first annealing process is: 450-520° C., keeping warm for 1-2 hours, and furnace cooling.

[0016] Preferably, the second annealing process is: 300-400° C., keeping warm for 1-2 hours, and furnace cooling.

[0017] Preferably, the third annealing process is: 250-350° C., keeping warm for 1-2 hours, and air cooling.

[0018] Preferably, the fourth annealing process is: 150-250° C., keeping warm for 15-60 minutes, and air cooling.

[0019] The principle of the present invention is to use gas-assisted continuous casting and extrusion to improve the plasticity of the alloy, use drawing deformation + annealing to reduce the diameter of the alloy round rod, and use peeling to remove pollutants on the surface of the wire, finally obtaining AlSi10Mg alloy wire that can be used for additive manufacturing.

[0020] Beneficial effects of the present invention:

[0021] Gas-assisted continuous casting and extrusion can improve the plasticity of AlSi10Mg alloy and lay a solid foundation for drawing deformation. There are two reasons for this: First, the conductive heat transfer of the extrusion wheel and the convective heat transfer of the inert gas can achieve non-equilibrium solidification of the thin layer of melt. On the one hand, it can increase the solid solubility of the alloy elements in the aluminum matrix and reduce the volume fraction of the hard and brittle second phase. On the other hand, it can increase the nucleation rate of the second phase and reduce the size of the second phase. Both aspects are beneficial to improving the plasticity of the alloy. Second, the semi-solid thin billet still at the eutectic temperature is blocked in front of the plug and then extruded. The flow of the remaining liquid phase will change the distribution state of the solute in the liquid phase at the front of the solid-liquid interface, interfere with the formation process of lamellar eutectic silicon, and then obtain nearly spherical eutectic silicon, which will significantly reduce the splitting effect of eutectic silicon on the matrix, which is beneficial to improving the plasticity of the alloy. Under the synergistic effect of the above-mentioned multiple factors, the plasticity of the alloy can be improved by 2-3 times compared with the cast alloy. The production method of AlSi10Mg alloy wire proposed in the present invention has the advantages of short process, low cost, simple operation, etc., and is convenient for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Flow chart for preparing AlSi10Mg alloy wire for additive manufacturing;

[0023] Figure 2 This is the principle diagram of gas-assisted continuous casting and extrusion.

[0024] In the figure: 1-funnel; 2-melt; 3-extrusion wheel; 4-extrusion wheel groove; 5-mold cavity; 6-mold; 7-extrusion rod; 8-injection device. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0026] The device used in the embodiment of the present invention is as follows Figure 2 As shown, it includes a funnel 1, a melt 2, an extrusion wheel 3, an extrusion wheel groove 4, a die cavity 5, a mold 6, an extrusion rod 7, and an air injection device 8; the smelted metal melt 2 flows into the extrusion wheel groove 4 from the preheated funnel 1 located above the extrusion wheel 3. Under the action of the inert gas, the melt spreads out closely against the wall of the extrusion wheel groove and begins to solidify. After encountering a blockage, the solidifying billet begins to accumulate and gradually transfers into the die cavity 5, and is finally extruded from the die hole to form an alloy rod 7.

[0027] Example 1

[0028] A method for preparing AlSi10Mg alloy wire for additive manufacturing comprises the following steps:

[0029] (1) Material preparation: According to the mass percentage of Si: 10%, Mg: 0.5%; the balance is Al, weigh the aluminum-silicon master alloy, pure magnesium ingot and aluminum ingot respectively.

[0030] (2) Melting: Place the aluminum-silicon master alloy and aluminum ingot into a furnace for melting. When the melt temperature reaches 750°C, keep it warm for 60 minutes, add the magnesium ingot, and stir until the mixture is uniform. During the stirring process, the melt temperature is maintained at 750°C. Finally, keep it warm at 700°C for 60 minutes to complete the melting.

[0031] (3) Preparation of AlSi10Mg alloy rod by gas-assisted continuous casting and extrusion: the smelted metal melt flows into the extrusion wheel groove from a preheated funnel (funnel diameter is 2.8 mm, preheating temperature is 850°C) located above the extrusion wheel. Under the action of inert gas (nitrogen gas, gas pressure is 0.4 MPa), the melt spreads out close to the wall of the extrusion wheel groove and begins to solidify. After encountering a blockage, the solidifying billet begins to accumulate and gradually transfers into the die cavity, and is finally extruded from the die hole to form an alloy rod; the die cavity preheating temperature is 400°C, the extrusion wheel speed is 15 rpm, and the die hole diameter is 8 mm.

[0032] (4) The 8 mm alloy rod prepared in step (3) is subjected to a drawing process: the rod is drawn from a diameter of 8 mm to 6.2 mm, at which time the drawing deformation is 22.5%, and the first annealing process is performed at 500°C, kept warm for 1 hour, and furnace cooled; the drawing process is continued, the rod is drawn from a diameter of 6.2 mm to 4.1 mm, at which time the drawing deformation is 33.9%, and the second annealing process is performed at 330°C, kept warm for 2 hours, and furnace cooled; the drawing process is continued, the rod is drawn from a diameter of 4.1 mm to 2.1 mm, at which time the drawing deformation is 48.8%, and the third annealing process is performed at 300°C, kept warm for 2 hours, and air cooled; and finally the rod is drawn to 1.4 mm.

[0033] (5) Finally, the 1.4 mm diameter alloy wire in step (4) was peeled to obtain an AlSi10Mg alloy wire with a diameter of 1.3 mm for additive manufacturing, without wire breakage.

[0034] Example 2

[0035] A method for preparing AlSi10Mg alloy wire for additive manufacturing comprises the following steps:

[0036] (1) Material preparation: According to the mass percentage of Si: 9%, Mg: 0.3%; the balance is Al, weigh the aluminum-silicon master alloy, pure magnesium ingot and aluminum ingot respectively.

[0037] (2) Melting: Place the aluminum-silicon master alloy and aluminum ingot into a furnace for melting. When the melt temperature reaches 800°C, keep it warm for 30 minutes, add the magnesium ingot, and stir until the mixture is uniform. During the stirring process, the melt temperature is maintained at 750°C. Finally, keep it warm at 750°C for 30 minutes to complete the melting.

[0038] (3) Preparation of AlSi10Mg alloy rod by gas-assisted continuous casting and extrusion: the smelted metal melt flows into the extrusion wheel groove from a preheated funnel (funnel diameter is 2 mm, preheating temperature is 870℃) located above the extrusion wheel. Under the action of inert gas (nitrogen, gas pressure is 0.2 MPa), the melt spreads out close to the wall of the extrusion wheel groove and begins to solidify. After encountering a blockage, the solidifying billet begins to accumulate and gradually transfers into the die cavity, and is finally extruded from the die hole to form an alloy rod; the die cavity preheating temperature is 350℃, the extrusion wheel speed is 5 rpm, and the die hole diameter is 8 mm.

[0039] (4) The 8 mm alloy rod obtained in step (3) was subjected to drawing treatment. Drawing from 8mm diameter to 6.2mm, at this time the drawing deformation is 22.5%, the first annealing treatment is carried out, the annealing process is 520℃, holding temperature for 1.2h, and furnace cooling; continuing the drawing process, drawing from 6.2mm diameter to 4.1mm, at this time the drawing deformation is 33.9%, the second annealing treatment is carried out, the annealing process is 300℃, holding temperature for 2h, and furnace cooling; continuing the drawing process, drawing from 4.1mm diameter to 2.1mm, at this time the drawing deformation is 48.8%, the third annealing treatment is carried out, the annealing process is 250℃, holding temperature for 2h, and air cooling; continuing the drawing process, drawing from 2.1mm diameter to 1.4mm, at this time the drawing deformation is 33.3%, the fourth annealing treatment is carried out, the annealing process is 250℃, holding temperature for 15min, and air cooling; continuing the drawing process, drawing from 1.4mm diameter to 1.1mm.

[0040] (5) Finally, the 1.1 mm diameter alloy wire in step (4) was peeled to obtain a 1.0 mm diameter AlSi10Mg alloy wire for additive manufacturing without wire breakage.

[0041] Example 3

[0042] A method for preparing AlSi10Mg alloy wire for additive manufacturing comprises the following steps:

[0043] (1) Material preparation: According to the mass percentage of Si: 11%, Mg: 0.6%; the balance is Al, weigh the aluminum-silicon master alloy, pure magnesium ingot and aluminum ingot respectively.

[0044] (2) Melting: Place the aluminum-silicon master alloy and aluminum ingot into a furnace for melting. When the melt temperature reaches 780°C, keep it warm for 50 minutes, add the magnesium ingot, and stir until the mixture is uniform. During the stirring process, the melt temperature is maintained at 750°C. Finally, keep it warm at 730°C for 40 minutes to complete the melting.

[0045] (3) Preparation of AlSi10Mg alloy rod by gas-assisted continuous casting and extrusion: the smelted metal melt flows into the extrusion wheel groove from a preheated funnel (funnel diameter is 4 mm, preheating temperature is 880℃) located above the extrusion wheel. Under the action of inert gas (nitrogen, gas pressure is 0.3MPa), the melt spreads out close to the wall of the extrusion wheel groove and begins to solidify. After encountering a blockage, the solidifying billet begins to accumulate and gradually transfers into the die cavity, and is finally extruded from the die hole to form an alloy rod; the die cavity preheating temperature is 450℃, the extrusion wheel speed is 8rpm, and the die hole diameter is 8mm.

[0046] (4) The 8 mm alloy rod obtained in step (3) was subjected to drawing treatment. Drawing from 8mm diameter to 6.2mm, at this time the drawing deformation is 22.5%, the first annealing treatment is carried out, the annealing process is 450℃, keep warm for 2h, and furnace cooling; continue drawing treatment, drawing from 6.2mm diameter to 4.1mm, at this time the drawing deformation is 33.9%, the second annealing treatment is carried out, the annealing process is 400℃, keep warm for 1h, and furnace cooling; continue drawing treatment, drawing from 4.1mm diameter to 2.1mm, at this time the drawing deformation is 48.8%, the third annealing treatment is carried out, the annealing process is 350℃, keep warm for 1h, and air cooling; continue drawing treatment, drawing from 2.1mm diameter to 1.4mm, at this time the drawing deformation is 33.3%, the fourth annealing treatment is carried out, the annealing process is 150℃, keep warm for 60min, and air cooling; continue drawing treatment, drawing from 1.4mm diameter to 1.1mm.

[0047] (5) Finally, the 1.1 mm diameter alloy wire in step (4) was peeled to obtain a 1.0 mm diameter AlSi10Mg alloy wire for additive manufacturing without wire breakage.

[0048] Comparative Example 1

[0049] (1) Material preparation: Si: 10%, Mg: 0.5%; the balance is Al, weigh the aluminum-silicon master alloy, pure magnesium ingot and aluminum ingot respectively.

[0050] (2) Melting: Place the aluminum-silicon master alloy and aluminum ingot into a furnace for melting. When the melt temperature reaches 750°C, keep it warm for 60 minutes, add the magnesium ingot, and stir until the mixture is uniform. During the stirring process, the melt temperature is maintained at 750°C. Finally, keep it warm at 700°C for 60 minutes to complete the melting.

[0051] (3) Casting: The alloy solution prepared in step (2) was poured into a Φ8 mm casting mold to obtain an AlSi10Mg alloy rod with a diameter of 8 mm.

[0052] (4) The alloy rod obtained in step (3) is subjected to multiple single-mode drawing until it reaches 7.1 mm and brittle fracture occurs.

[0053] (5) The 7.1 mm alloy rod was annealed at 500 ° C, kept at this temperature for 1 hour, and then cooled in the furnace. The drawing process was continued until the wire broke frequently when the rod was drawn to 6.1 mm.

[0054] Comparative Example 2

[0055] (1) Material preparation: Si: 11%, Mg: 0.4%; the balance is Al, weigh the aluminum-silicon master alloy, pure magnesium ingot and aluminum ingot respectively.

[0056] (2) Melting: Place the aluminum-silicon master alloy and aluminum ingot into a furnace for melting. When the melt temperature reaches 800°C, keep it warm for 60 minutes, add the magnesium ingot, and stir until the mixture is uniform. During the stirring process, the melt temperature is maintained at 750°C. Finally, keep it warm at 750°C for 60 minutes to complete the melting.

[0057] (3) Casting: The alloy solution prepared in step (2) was poured into a Φ8 mm casting mold to obtain an AlSi10Mg alloy rod with a diameter of 8 mm.

[0058] (4) The alloy rod obtained in step (3) is subjected to multiple single-mode drawing until it reaches 6.9 mm and brittle fracture occurs.

[0059] (5) The 6.9 mm alloy rod was annealed at 500 ° C, kept at this temperature for 2 h, and then cooled in the furnace. The drawing process was continued until the wire broke frequently when the rod was drawn to 5.4 mm.

[0060] By comparing Examples 1 and 2, the AlSi10Mg alloy rod obtained by conventional casting has low plasticity and brittle fracture occurs when the drawing deformation is small. The plasticity is not significantly improved by annealing treatment.

Claims

1. A method for preparing AlSi10Mg alloy wire for additive manufacturing, characterized by: The specific steps include: (1) Material preparation: According to the mass percentage of Si: 9-11%, Mg: 0.3-0.6%; the balance is Al, weigh the aluminum-silicon master alloy, pure magnesium ingot, and aluminum ingot respectively; (2) Melting: Place the aluminum-silicon master alloy and aluminum ingot into the furnace for melting. When the melt temperature reaches 750-800°C, keep it warm for 30-60 minutes, add the magnesium ingot, and stir until the mixture is uniform. During the stirring process, the melt temperature is maintained at 750-800°C. Finally, keep it warm at 700-750°C for 30-60 minutes to complete the melting. (3) The alloy melt in step (2) is subjected to gas-assisted continuous casting and extrusion to obtain an AlSi10Mg alloy rod; (4) The alloy rod obtained in step (3) is cold drawn to obtain a wire, and annealing is performed once when the cumulative deformation is 20%-50%; (5) peeling the wire in step (4) to obtain an AlSi10Mg alloy wire with a diameter of 0.8-1.5 mm; In step (4), the drawing process requires 3-4 annealing steps, with an annealing temperature of 150-520°C and an annealing time of 0.25-2h; The first annealing process is: 450-520℃, keep warm for 1-2h, and then cool in the furnace; The second annealing process is: 300-400℃, keep warm for 1-2h, and then cool in the furnace; The third annealing process is: 250-350℃, keep warm for 1-2h, and air cool; The fourth annealing process is: 150-250℃, holding time 15-60min, air cooling; In step (3), the specific process of gas-assisted continuous casting and extrusion is as follows: the smelted metal melt flows into the extrusion wheel groove from the preheated funnel located above the extrusion wheel. Under the action of the inert gas, the melt spreads closely against the wall of the extrusion wheel groove and begins to solidify. After encountering a blockage, the solidifying billet begins to accumulate and gradually transfers into the die cavity, and is finally extruded from the die hole to form an alloy rod.

2. The method for preparing the AlSi10Mg alloy wire for additive manufacturing according to claim 1, characterized in that: The diameter of the funnel in step (3) is 2-4 mm, and the funnel needs to be heated to 850-880°C before pouring the alloy melt.

3. The method for preparing the AlSi10Mg alloy wire for additive manufacturing according to claim 1, characterized in that: In step (3), the inert gas is nitrogen or argon, and the gas pressure is 0.2-0.4 MPa.

4. The method for preparing the AlSi10Mg alloy wire for additive manufacturing according to claim 1, characterized in that: The rotation speed of the extrusion wheel in step (3) is 5-15 rpm.

5. The method for preparing the AlSi10Mg alloy wire for additive manufacturing according to claim 1, characterized in that: In step (3), the preheating temperature of the extrusion die cavity is 350-450°C, and the die hole diameter is 8-10 mm.

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