AZ80 magnesium alloy electric arc additive manufacturing method based on pulse period regulation and interlayer temperature collaborative optimization

Abstract

The invention discloses an AZ80 magnesium alloy electric arc additive manufacturing method based on pulse period regulation and interlayer temperature collaborative optimization, which comprises the following steps: 1, carrying out digital modeling on an AZ80 magnesium alloy workpiece by utilizing three-dimensional modeling software, and carrying out slicing treatment and path planning; 2, the magnesium alloy substrate is fixed and preheated, and electric arc additive manufacturing equipment is arranged; thirdly, the AZ80 magnesium alloy coiled wire is installed on wire feeding equipment; 4, setting parameters, and controlling a pulse period; fifthly, electric arc additive manufacturing is conducted, and the interlayer temperature is controlled; and 6, obtaining the AZ80 magnesium alloy workpiece. By considering the physical property characteristics of the AZ80 magnesium alloy and various factors in the electric arc additive manufacturing process, the electric arc additive manufacturing method capable of accurately regulating and controlling the pulse period and the interlayer temperature is adopted, uniform precipitation of a second phase is promoted, formation of defects such as coarse second phase and pores is effectively inhibited, and the obtained AZ80 magnesium alloy workpiece is fine and uniform in structure and high in mechanical strength. Good comprehensive mechanical properties are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal arc additive manufacturing, and particularly relates to an arc additive manufacturing method for AZ80 magnesium alloy based on the collaborative optimization of pulse period regulation and interlayer temperature. Background Art

[0002] Due to its excellent specific strength, specific stiffness, electromagnetic shielding performance and recyclability, magnesium alloy has become a highly potential lightweight material in fields such as aerospace. At present, its manufacturing mainly relies on casting and deformation processes (such as hot rolling, hot extrusion, forging). However, the deformation process has problems such as high cost, easy oxidation, and difficulty in forming complex structures, while the casting process faces challenges such as element segregation, large grain size, and insufficient mechanical properties. With the increasing demand for high efficiency and high performance in the manufacturing industry, the arc additive manufacturing (AM) technology, with advantages such as high material utilization rate and fast forming of complex structures, provides a new way for the preparation of large-sized complex magnesium alloy components.

[0003] Cold metal transfer wire arc additive manufacturing (CMT-WAAM) shows unique potential in the processing of AZ80 magnesium alloy. However, it still faces the balance problem of regulating heat input and cooling rate, and is prone to problems such as grain coarsening, increased porosity, and uneven distribution of the second phase during the additive process, which in turn leads to a decrease in strength and is difficult to meet the industrial production requirements of high strength and high reliability for structural parts in the equipment manufacturing industry. Therefore, developing a new process method to improve the strength performance of arc additive manufacturing AZ80 magnesium alloy has become a key technological breakthrough point for promoting the engineering application of arc additive manufacturing magnesium alloy, and is of great significance for realizing the industrial production of high-performance magnesium alloy components. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an arc additive manufacturing method for AZ80 magnesium alloy based on the collaborative optimization of pulse period regulation and interlayer temperature in view of the above-mentioned deficiencies of the prior art. This method combines the advantages of cold metal transfer and pulsed arc, and optimizes the heat input and molten pool morphology by precisely regulating parameters such as the interlayer temperature, thereby improving the element distribution uniformity and reducing pore defects, increasing the strength of the arc additive manufacturing AZ80 magnesium alloy workpiece, increasing the pulse period, and cooperating with the CMT reverse extraction and back-burning mechanism and the precise regulation of the interlayer temperature, significantly improving the comprehensive performance.

[0005] To solve the above technical problem, the technical solution adopted by the present invention is: an arc additive manufacturing method for AZ80 magnesium alloy based on the collaborative optimization of pulse period regulation and interlayer temperature, characterized in that this method uses a pulsed arc as the heat source, and realizes precise control of the heat input to the molten pool by adjusting the pulse period and the interlayer temperature, and proceeds according to the following steps: Step 1: Use 3D modeling software to digitally model the AZ80 magnesium alloy workpiece. Then, after optimizing the dimensions and structure incrementally for the obtained 3D model, import it into the control software of the arc additive manufacturing equipment. Subsequently, perform slicing and path planning on the imported model. After ensuring that the slicing and path simulation are error-free, send it to the arc additive manufacturing equipment for operation to obtain an arc additive manufacturing equipment with data. Step 2: Polish the magnesium alloy substrate clean and fix it on the platform of the arc additive manufacturing equipment with data obtained in Step 2. Take the upper surface of the magnesium alloy substrate as the arc additive manufacturing reference plane. Then, adjust the gun head of the welding torch of the arc additive manufacturing equipment to be perpendicular to the magnesium alloy substrate. Subsequently, establish the workpiece coordinate and import the coordinate data into the control software of the arc additive manufacturing equipment. Then, preheat the magnesium alloy substrate through a heating plate to obtain an arc additive manufacturing equipment with a preheated magnesium alloy substrate. Step 3: Install the AZ80 magnesium alloy wire coil in the wire feeding equipment, and accurately introduce the end of the AZ80 magnesium alloy wire coil into the wire guiding tube of the welding torch of the arc additive manufacturing equipment with a preheated magnesium alloy substrate obtained in Step 2. Then, adjust the position of the welding torch to keep the working distance between the welding torch nozzle and the end of the AZ80 magnesium alloy wire coil. At the same time, introduce argon gas through the coaxial interface of the welding torch to obtain an arc additive manufacturing equipment and a wire feeding equipment ready for wire feeding. Step 4: Set the wire feeding speed, welding speed, arc voltage, weld width and weld height of the molten pool, pulse peak current, pulse base current, and pulse cycle number in the arc additive manufacturing equipment and wire feeding equipment ready for wire feeding obtained in Step 3 to obtain an arc additive manufacturing equipment and a wire feeding equipment ready for arc additive manufacturing. Step 5: Start the arc additive manufacturing equipment and wire feeding equipment ready for arc additive manufacturing obtained in Step 4 for arc additive manufacturing. Remove the oxide layer after each layer deposition and strictly control the interlayer temperature. Subsequently, continue arc additive manufacturing deposition until each single-pass solid slice is stacked layer by layer according to the error-free path obtained in Step 1 to obtain a formed part. Step 6: Let the formed part obtained in Step 5 be statically air-cooled in situ until room temperature to obtain the AZ80 magnesium alloy workpiece.

[0006] The research of the present invention finds that during the cold metal transfer welding + pulse (C+P) arc additive manufacturing process, the heat input has a decisive influence on the workpiece forming. When the current is larger, the amount of current passing through the welding wire is more, resulting in an increase in heat input. This will cause the temperature of the molten pool to rise, thereby affecting the size and shape of the molten pool. The increase in heat input leads to an increase in the temperature of the molten pool and a slowdown in the cooling rate, so the grains have more time to grow, resulting in an increase in grain size, which may affect the mechanical properties of the workpiece. Correspondingly, an increase in the wire feeding speed will cause an increase in the current density passing through the welding wire, thereby increasing the heat input, and will also affect the molten pool morphology and the cooling rate of the molten pool. Therefore, during the additive manufacturing process, the present invention controls the heat input by adjusting the welding current and the wire feeding speed, and further controls the molten pool morphology, ensuring the performance of the obtained AZ80 magnesium alloy workpiece. In addition, the manufactured formed part is slowly cooled to room temperature by in-situ static air cooling to prevent the magnesium alloy workpiece from deforming and cracking due to uneven or too fast heat dissipation.

[0007] The above-mentioned AZ80 magnesium alloy arc additive manufacturing method based on pulse period regulation and interlayer temperature collaborative optimization is characterized in that in the slicing process in step one, the slicing type is plane slicing, and the path planning is the central line path. The present invention ensures the geometric accuracy and material utilization rate of the workpiece by selecting appropriate slicing types and additive manufacturing paths.

[0008] The above-mentioned AZ80 magnesium alloy arc additive manufacturing method based on pulse period regulation and interlayer temperature collaborative optimization is characterized in that in step two, the preheating temperature of the magnesium alloy substrate is 130°C to 170°C. The present invention effectively reduces the residual stress and improves the bonding quality between the workpiece and the substrate by preheating the magnesium alloy substrate and controlling the preheating temperature.

[0009] The above-mentioned AZ80 magnesium alloy arc additive manufacturing method based on pulse period regulation and interlayer temperature collaborative optimization is characterized in that in step three, the diameter of the AZ80 magnesium alloy coil wire is 1.2 mm to 1.6 mm. The present invention can optimize the molten pool width by controlling the diameter of the magnesium alloy coil wire, thereby accurately controlling the single-pass forming size. On the other hand, it can ensure that the wire material is fully melted and effectively reduce the inclusion defects during the printing process.

[0010] The above-mentioned AZ80 magnesium alloy arc additive manufacturing method based on pulse period regulation and interlayer temperature collaborative optimization is characterized in that in step three, the working distance is 10 mm to 13 mm. The present invention can effectively maintain the stability of the arc by controlling the working distance between the welding torch tip and the substrate, thereby avoiding the blockage of the welding torch.

[0011] The above AZ80 magnesium alloy arc additive manufacturing method based on the collaborative optimization of pulse period regulation and interlayer temperature is characterized in that in step four, the wire feeding speed is 6000 mm / min to 8500 mm / min, the welding speed is 480 mm / min to 720 mm / min, the arc voltage is 10 V to 15 V, the set melt width of the molten pool is 5 mm to 12 mm, and the melt height is 1.8 mm to 2.2 mm. By regulating appropriate printing parameters, the present invention ensures that the melt width and melt height are maintained within a reasonable range during the reprinting process to guarantee the forming quality of the workpiece. Generally, before reaching the printing stable state, the printing quality is usually ensured by adjusting two parameters, namely the current and the wire feeding speed.

[0012] The above AZ80 magnesium alloy arc additive manufacturing method based on the collaborative optimization of pulse period regulation and interlayer temperature is characterized in that in step four, the pulse peak current is 360 A to 390 A, the pulse base current is 60 A to 90 A, and the number of pulse periods is 3 to 12. By regulating the pulse peak current, the pulse base current, and the pulse period, the present invention ensures that the heat can effectively melt the welding wire, avoids defects such as porosity or inclusions, and ensures the printing quality by adjusting two parameters, namely the current and the wire feeding speed.

[0013] The above AZ80 magnesium alloy arc additive manufacturing method based on the collaborative optimization of pulse period regulation and interlayer temperature is characterized in that in step five, the controlled interlayer temperature is 130 °C to 170 °C. By precisely controlling the interlayer temperature, the present invention can effectively inhibit the formation of hot cracks, significantly improve the interlayer bonding quality, and avoid the generation of porosity defects.

[0014] The present invention has the following advantages compared with the prior art: 1. The present invention combines the advantages of cold metal transfer (CMT) and pulsed arc. By precisely regulating parameters such as the interlayer temperature, the heat input and the molten pool morphology are optimized, thereby improving the element distribution uniformity and reducing porosity defects, and enhancing the strength of the AZ80 magnesium alloy workpiece manufactured by arc additive manufacturing. Compared with CMT arc additive manufacturing, the present invention adds a pulse period on this basis, cooperates with the CMT back-drawing and burning-back mechanism and the precise regulation of the interlayer temperature, promotes the uniform precipitation of the second phase, introduces fine and uniform second phases, effectively inhibits the formation of defects such as coarse second phases and porosity, and the obtained AZ80 magnesium alloy workpiece has fine and uniform microstructure and good comprehensive mechanical properties.

[0015] 2. In the arc additive manufacturing of the present invention, the electromagnetic stirring effect generated by the pulse enhances the fluidity of the molten pool, makes the interlayer bonding denser, reduces defects such as porosity and lack of fusion, and improves the comprehensive performance of the AZ80 magnesium alloy workpiece.

[0016] 3. In the arc additive manufacturing of the present invention, the sudden drop in heat input during the pulse base value stage accelerates the cooling of the molten pool, inhibits the precipitation of β-Mg 17 Al 12 coarse phases, and improves the uniformity of the microstructure.

[0017] 4. By regulating the interlayer temperature, the present invention effectively reduces the heat accumulation effect and avoids the abnormal growth of the β-Mg 17 Al 12 phase caused by too high temperature.

[0018] The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0019] Figure 1 is a schematic diagram of the process principle of the arc additive manufacturing of the present invention.

[0020] Figure 2 is a physical picture of the magnesium alloy substrate in the arc additive manufacturing of Examples 1 to 4 of the present invention.

[0021] Figure 3 is a physical picture of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0022] Figure 4 is a longitudinal sectional metallographic picture of the top position of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0023] Figure 5 is a longitudinal sectional metallographic picture of the middle position of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0024] Figure 6 is a longitudinal sectional metallographic picture of the bottom position of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0025] Figure 7 is the Mg element distribution picture of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0026] Figure 8 is the Al element distribution picture of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0027] Figure 9 is the Zn element distribution picture of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0028] Figure 10 is the Mn element distribution picture of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0029] Figure 11 is a physical picture of the AZ80 magnesium alloy workpiece prepared in Example 2 of the present invention.

[0030] Figure 12 It is the longitudinal cross - section metallographic diagram of the top position of the AZ80 magnesium alloy workpiece prepared in Example 2 of the present invention.

[0031] Figure 13 It is the longitudinal cross - section metallographic diagram of the middle position of the AZ80 magnesium alloy workpiece prepared in Example 2 of the present invention.

[0032] Figure 14 It is the longitudinal cross - section metallographic diagram of the bottom position of the AZ80 magnesium alloy workpiece prepared in Example 2 of the present invention.

[0033] Figure 15 It is the distribution diagram of Mg element of the AZ80 magnesium alloy workpiece prepared in Example 2 of the present invention.

[0034] Figure 16 It is the distribution diagram of Al element of the AZ80 magnesium alloy workpiece prepared in Example 1 of the present invention.

[0035] Figure 17 It is the distribution diagram of Zn element of the AZ80 magnesium alloy workpiece prepared in Example 2 of the present invention.

[0036] Figure 18 It is the distribution diagram of Mn element of the AZ80 magnesium alloy workpiece prepared in Example 2 of the present invention.

[0037] Figure 19 It is the mechanical property diagram of the AZ80 magnesium alloy workpieces prepared in Example 1 and Example 2 of the present invention. Detailed implementation manners

[0038] Figure 1 It is the schematic diagram of the process principle of the arc additive manufacturing of the present invention. As can be seen from Figure 1 it, the wire feeding device imports the AZ80 magnesium alloy wire coil into the welding torch, and at the same time, argon gas is introduced through the coaxial interface of the welding torch. In the arc additive manufacturing, a pulsed arc is used as the heat source to form a molten pool, realizing the preparation of the AZ80 magnesium alloy workpiece.

[0039] Figure 2 It is the physical diagram of the magnesium alloy substrate in the arc additive manufacturing of Examples 1 - 4 of the present invention. As can be seen from Figure 2 it, the magnesium alloy substrates in the arc additive manufacturing of Examples 1 - 4 of the present invention are in the shape of circular plates.

[0040] Example 1 In this example, the AZ80 magnesium alloy wire coil is used as the raw material, and a pulsed arc is used as the heat source. By adjusting the pulse period and the interlayer temperature, precise control of the heat input to the molten pool is achieved.

[0041] This example includes the following steps: Step 1: Use 3D modeling software to digitally model the AZ80 magnesium alloy workpiece. Then, after optimizing the dimensions and structure increments of the obtained 3D model, import it into the control software of the arc additive manufacturing equipment. Subsequently, perform slicing processing and path planning on the imported model. After ensuring that the slicing and path simulations are error-free, send it to the arc additive manufacturing equipment for operation to obtain an arc additive manufacturing equipment with data; in the slicing process, the slicing type is planar slicing, and the path planning is a center line path; Step 2: Polish the magnesium alloy substrate clean and fix it on the platform of the arc additive manufacturing equipment with data obtained in Step 2. Take the upper surface of the magnesium alloy substrate as the arc additive manufacturing reference plane. Then, adjust the gun head of the welding torch of the arc additive manufacturing equipment to be perpendicular to the magnesium alloy substrate. Subsequently, establish the workpiece coordinate and import the coordinate data into the control software of the arc additive manufacturing equipment. Then, preheat the magnesium alloy substrate to 150 °C through a heating plate to obtain an arc additive manufacturing equipment with a preheated magnesium alloy substrate; Step 3: Install a 1.2 mm diameter AZ80 magnesium alloy wire coil in the wire feeding equipment, and accurately introduce the end of the AZ80 magnesium alloy wire coil into the wire guiding tube of the welding torch of the arc additive manufacturing equipment with a preheated magnesium alloy substrate obtained in Step 2. Then, adjust the position of the welding torch so that the working distance between the welding torch nozzle and the end of the AZ80 magnesium alloy wire coil is 13 mm. At the same time, introduce argon gas with a flow rate of 20 L / min through the coaxial interface of the welding torch to obtain an arc additive manufacturing equipment and a wire feeding equipment ready for wire feeding; Step 4: Set the wire feeding speed, welding speed, arc voltage, weld width and weld height of the molten pool, pulse peak current, pulse base current, and pulse cycle number in the arc additive manufacturing equipment and wire feeding equipment ready for wire feeding obtained in Step 3 to obtain an arc additive manufacturing equipment and a wire feeding equipment ready for arc additive manufacturing; the wire feeding speed is 7000 mm / min, the welding speed is 550 mm / min, the arc voltage is 12 V, the set weld width of the molten pool is 8 mm, the weld height is 1.8 mm, the pulse peak current is 380 A, the pulse base current is 80 A, and the pulse cycle number is 5; Step 5: Start the arc additive manufacturing equipment and wire feeding equipment ready for arc additive manufacturing obtained in Step 4 for arc additive manufacturing. Remove the oxide layer after each layer deposition, and strictly control the interlayer temperature at 150 °C. Subsequently, continue the arc additive manufacturing deposition until each single-pass solid layer is stacked layer by layer according to the error-free path obtained in Step 1 to obtain a formed part; Step 6: Let the formed part obtained in Step 5 stand still in situ and air-cool to room temperature to obtain the AZ80 magnesium alloy workpiece.

[0042] Figure 3 is a physical diagram of the AZ80 magnesium alloy workpiece prepared in this embodiment. From Figure 3It can be seen that the AZ80 magnesium alloy workpiece prepared in this embodiment has a dense interlayer bonding, without defects such as pores and lack of fusion.

[0043] Figure 4 is the longitudinal section metallographic diagram of the top position of the AZ80 magnesium alloy workpiece prepared in this embodiment, Figure 5 is the longitudinal section metallographic diagram of the middle position of the AZ80 magnesium alloy workpiece prepared in this embodiment, Figure 6 is the longitudinal section metallographic diagram of the bottom position of the AZ80 magnesium alloy workpiece prepared in this embodiment. From Figures 4 - 6 it can be seen that the AZ80 magnesium alloy workpiece prepared in this embodiment has uniform equiaxed crystals from top to bottom.

[0044] Figure 7 is the Mg element distribution diagram of the AZ80 magnesium alloy workpiece prepared in this embodiment, Figure 8 is the Al element distribution diagram of the AZ80 magnesium alloy workpiece prepared in this embodiment, Figure 9 is the Zn element distribution diagram of the AZ80 magnesium alloy workpiece prepared in this embodiment, Figure 10 is the Mn element distribution diagram of the AZ80 magnesium alloy workpiece prepared in this embodiment. From Figures 7 - 10 it can be seen that the distribution of each element in the AZ80 magnesium alloy workpiece prepared in this embodiment is relatively uniform.

[0045] Example 2 In this embodiment, AZ80 magnesium alloy wire is used as the raw material, and pulsed arc is used as the heat source. By adjusting the pulse period and interlayer temperature, precise control of the heat input to the molten pool is achieved.

[0046] This embodiment includes the following steps: Step 1: Use three-dimensional modeling software to digitally model the AZ80 magnesium alloy workpiece, then optimize the size and structure increment of the obtained three-dimensional model and import it into the control software of the arc additive manufacturing equipment. Subsequently, perform slicing processing and path planning on the imported model. After ensuring that the slicing and path simulation are error-free, send it to the arc additive manufacturing equipment for operation to obtain an arc additive manufacturing equipment with data; in the slicing processing, the slicing type is plane slicing, and the path planning is the center line path; Step 2: Polish the magnesium alloy substrate and fix it on the platform of the arc additive manufacturing equipment with data obtained in Step 2. Take the upper surface of the magnesium alloy substrate as the arc additive manufacturing reference surface, then adjust the gun head of the welding torch of the arc additive manufacturing equipment to be perpendicular to the magnesium alloy substrate. Subsequently, establish the workpiece coordinate and import the coordinate data into the control software of the arc additive manufacturing equipment. Then preheat the magnesium alloy substrate to 150 °C through a heating plate to obtain an arc additive manufacturing equipment with a preheated magnesium alloy substrate; Step 3: Install an AZ80 magnesium alloy wire with a diameter of 1.2 mm in the wire feeding device, and accurately introduce the end of the AZ80 magnesium alloy wire into the wire guide tube of the welding torch of the arc additive manufacturing device with the preheated magnesium alloy substrate obtained in Step 2. Then, adjust the position of the welding torch so that the working distance between the welding torch nozzle and the end of the AZ80 magnesium alloy wire is 13 mm. At the same time, introduce argon with a flow rate of 20 L / min through the coaxial interface of the welding torch to obtain the arc additive manufacturing device and the wire feeding device to be wire-fed; Step 4: Set the wire feeding speed, welding speed, arc voltage, weld width and weld height of the molten pool, pulse peak current, pulse base current, and number of pulse cycles in the arc additive manufacturing device and the wire feeding device to be wire-fed obtained in Step 3 to obtain the arc additive manufacturing device and the wire feeding device to be arc additively manufactured; the wire feeding speed is 7500 mm / min, the welding speed is 600 mm / min, the arc voltage is 15 V, the set weld width of the molten pool is 10 mm, the weld height is 2.0 mm, the pulse peak current is 390 A, the pulse base current is 85 A, and the number of pulse cycles is 10; Step 5: Start the arc additive manufacturing device and the wire feeding device to be arc additively manufactured obtained in Step 4 for arc additive manufacturing. Remove the oxide layer after each layer deposition, and strictly control the interlayer temperature at 150 °C. Then continue the arc additive manufacturing deposition until each single-pass solid slice layer is stacked layer by layer according to the path obtained after the simulation in Step 1 is error-free to obtain the formed part; Step 6: Let the formed part obtained in Step 5 be statically air-cooled in situ until room temperature to obtain the AZ80 magnesium alloy workpiece.

[0047] Figure 11 is a physical drawing of the AZ80 magnesium alloy workpiece prepared in this embodiment. From Figure 11 it can be seen that the AZ80 magnesium alloy workpiece prepared in this embodiment has dense interlayer bonding and no defects such as pores and lack of fusion.

[0048] Figure 12 is a longitudinal section metallographic diagram of the top position of the AZ80 magnesium alloy workpiece prepared in this embodiment, Figure 13 is a longitudinal section metallographic diagram of the middle position of the AZ80 magnesium alloy workpiece prepared in this embodiment, Figure 14 is a longitudinal section metallographic diagram of the bottom position of the AZ80 magnesium alloy workpiece prepared in this embodiment. From Figures 12 - 14 it can be seen that the AZ80 magnesium alloy workpiece prepared in this embodiment has an equiaxed crystal structure with uniform distribution, and the content of the second phase is significantly reduced compared with that of Example 1.

[0049] Figure 15 is the Mg element distribution diagram of the AZ80 magnesium alloy workpiece prepared in this embodiment, Figure 16 is the Al element distribution diagram of the AZ80 magnesium alloy workpiece prepared in this embodiment,Figure 17 It is the Zn element distribution map of the AZ80 magnesium alloy workpiece prepared in this embodiment. Figure 18 It is the Mn element distribution map of the AZ80 magnesium alloy workpiece prepared in this embodiment. As can be seen from Figures 15 - 18 this, the element distribution in the AZ80 magnesium alloy workpiece prepared in this embodiment is relatively uniform, and is more uniform than the element distribution in Embodiment 1.

[0050] The AZ80 magnesium alloy workpieces prepared in Embodiment 1 and Embodiment 2 were subjected to mechanical property tests. See Figure 19 It can be seen that the room temperature tensile properties in the horizontal and vertical directions of the AZ80 magnesium alloy workpiece prepared in Embodiment 1 are close. The average room temperature tensile properties are: yield strength 142 MPa ± 3 MPa, tensile strength 280 MPa ± 10 MPa, elongation 12% ± 2%; The room temperature tensile properties of the AZ80 magnesium alloy workpiece prepared in Embodiment 2 in the horizontal and vertical directions are close and higher than those in Embodiment 1. The average room temperature tensile properties are: yield strength 145 MPa ± 1 MPa, tensile strength 297 MPa ± 2 MPa, elongation 13% ± 1%.

[0051] Embodiment 3 In this embodiment, AZ80 magnesium alloy wire rods are used as raw materials, and pulsed arc is used as the heat source. By adjusting the pulse period and interlayer temperature, precise control of the heat input to the molten pool is achieved.

[0052] This embodiment includes the following steps: Step 1: Use 3D modeling software to digitally model the AZ80 magnesium alloy workpiece, then optimize the size and structure increments of the obtained 3D model and import it into the control software of the arc additive manufacturing equipment. Subsequently, perform slicing processing and path planning on the imported model. After ensuring that the slicing and path simulation are error-free, send it to the arc additive manufacturing equipment for operation to obtain an arc additive manufacturing equipment with data; In the slicing process, the slicing type is planar slicing, and the path planning is the central line path; Step 2: Polish the magnesium alloy substrate and fix it on the platform of the arc additive manufacturing equipment with data obtained in Step 2. Take the upper surface of the magnesium alloy substrate as the arc additive manufacturing reference surface, then adjust the gun head of the welding torch of the arc additive manufacturing equipment to be perpendicular to the magnesium alloy substrate. Subsequently, establish the workpiece coordinates and import the coordinate data into the control software of the arc additive manufacturing equipment. Then preheat the magnesium alloy substrate to 130 °C through a heating plate to obtain an arc additive manufacturing equipment with a preheated magnesium alloy substrate; Step 3: Install an AZ80 magnesium alloy wire coil with a diameter of 1.4 mm in the wire feeding device, and accurately introduce the end of the AZ80 magnesium alloy wire coil into the wire guide tube of the welding torch of the arc additive manufacturing device with the preheated magnesium alloy substrate obtained in Step 2. Then, adjust the position of the welding torch so that the working distance between the welding torch nozzle and the end of the AZ80 magnesium alloy wire coil is 10 mm. At the same time, introduce argon gas through the coaxial interface of the welding torch to obtain the arc additive manufacturing device and the wire feeding device to be wire-fed; Step 4: Set the wire feeding speed, welding speed, arc voltage, weld width and weld height of the molten pool, pulse peak current, pulse base current, and number of pulse cycles in the arc additive manufacturing device and the wire feeding device to be wire-fed obtained in Step 3 to obtain the arc additive manufacturing device and the wire feeding device to be arc-additively manufactured; the wire feeding speed is 6000 mm / min, the welding speed is 480 mm / min, the arc voltage is 10 V, the set weld width of the molten pool is 5 mm, the weld height is 2.0 mm, the pulse peak current is 360 A, the pulse base current is 60 A, and the number of pulse cycles is 3; Step 5: Start the arc additive manufacturing device and the wire feeding device to be arc-additively manufactured obtained in Step 4 for arc additive manufacturing. After each layer is deposited, remove the oxide layer, and strictly control the interlayer temperature at 130 °C. Then continue the arc additive manufacturing deposition until each single-pass solid slice layer is stacked layer by layer according to the path obtained after the simulation in Step 1 is correct to obtain the formed part; Step 6: Let the formed part obtained in Step 5 stand still in situ and air-cool until room temperature to obtain the AZ80 magnesium alloy workpiece.

[0053] Example 4 In this example, an AZ80 magnesium alloy wire coil is used as the raw material, and a pulsed arc is used as the heat source. By adjusting the pulse period and interlayer temperature, precise control of the heat input to the molten pool is achieved.

[0054] This example includes the following steps: Step 1: Digitally model the AZ80 magnesium alloy workpiece using 3D modeling software, then optimize the dimensions and structure increments of the obtained 3D model and import it into the control software of the arc additive manufacturing device. Subsequently, perform slicing processing and path planning on the imported model. After ensuring that the slicing and path simulations are correct, send it to the arc additive manufacturing device for operation to obtain the arc additive manufacturing device with data; the slicing type in the slicing process is planar slicing, and the path planning is a central line path; Step 2: After polishing the magnesium alloy substrate clean, fix it on the platform of the arc additive manufacturing equipment with data obtained in Step 2. Take the upper surface of the magnesium alloy substrate as the arc additive manufacturing reference plane. Then adjust the gun head of the welding torch of the arc additive manufacturing equipment to be perpendicular to the magnesium alloy substrate. Subsequently, establish the workpiece coordinates and import the coordinate data into the control software of the arc additive manufacturing equipment. Then preheat the magnesium alloy substrate to 170°C through a heating plate to obtain the arc additive manufacturing equipment with a preheated magnesium alloy substrate; Step 3: Install the AZ80 magnesium alloy wire with a diameter of 1.6 mm in the wire feeding equipment, and accurately introduce the end of the AZ80 magnesium alloy wire into the wire guiding tube of the welding torch of the arc additive manufacturing equipment with a preheated magnesium alloy substrate obtained in Step 2. Then adjust the position of the welding torch so that the working distance between the welding torch nozzle and the end of the AZ80 magnesium alloy wire is 12 mm. At the same time, introduce argon gas through the coaxial interface of the welding torch to obtain the arc additive manufacturing equipment and the wire feeding equipment to be wire-fed; Step 4: Set the wire feeding speed, welding speed, arc voltage, weld width and weld height of the molten pool, pulse peak current, pulse base current, and pulse cycle number in the arc additive manufacturing equipment and the wire feeding equipment to be wire-fed obtained in Step 3. The wire feeding speed is 8500 mm / min, the welding speed is 720 mm / min, the arc voltage is 14 V, the set weld width of the molten pool is 12 mm, the weld height is 2.2 mm, the pulse peak current is 370 A, the pulse base current is 90 A, and the pulse cycle number is 12; Step 5: Start the arc additive manufacturing equipment and the wire feeding equipment to be arc-additively manufactured obtained in Step 4 for arc additive manufacturing. Remove the oxide layer after each layer of deposition, and strictly control the interlayer temperature at 170°C. Subsequently, continue the arc additive manufacturing deposition until each single-pass solid slice layer is stacked layer by layer according to the path obtained after the simulation in Step 1 is correct to obtain a formed part; Step 6: Let the formed part obtained in Step 5 stand still in situ and air-cool until room temperature to obtain an AZ80 magnesium alloy workpiece.

[0055] The above is only a preferred embodiment of the present invention and does not impose any limitation on the present invention. Any simple modification, change, and equivalent change made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. An AZ80 magnesium alloy arc additive manufacturing method based on coordinated optimization of pulse period regulation and interlayer temperature, characterized in that This method uses a pulsed arc as the heat source, and precisely controls the heat input to the molten pool by adjusting the pulse period and the interlayer temperature. The steps are as follows: Step 1: Digitally model the AZ80 magnesium alloy workpiece using 3D modeling software. Then, after optimizing the dimensions and structure increments of the obtained 3D model, import it into the control software of the arc additive manufacturing equipment. Subsequently, perform slicing processing and path planning on the imported model. After ensuring that the slicing and path simulation are error-free, send it to the arc additive manufacturing equipment for operation to obtain an arc additive manufacturing equipment with data. Step 2: Polish the magnesium alloy substrate and fix it on the platform of the arc additive manufacturing equipment with data obtained in Step 2. Use the upper surface of the magnesium alloy substrate as the arc additive manufacturing reference plane. Then, adjust the gun head of the welding torch of the arc additive manufacturing equipment to be perpendicular to the magnesium alloy substrate. Subsequently, establish the workpiece coordinates and import the coordinate data into the control software of the arc additive manufacturing equipment. Then, preheat the magnesium alloy substrate through a heating plate to obtain an arc additive manufacturing equipment with a preheated magnesium alloy substrate. Step 3: Install the AZ80 magnesium alloy wire coil in the wire feeding equipment, and precisely introduce the end of the AZ80 magnesium alloy wire coil into the wire guiding tube of the welding torch of the arc additive manufacturing equipment with a preheated magnesium alloy substrate obtained in Step 2. Then, adjust the position of the welding torch so that the nozzle of the welding torch maintains a working distance from the end of the AZ80 magnesium alloy wire coil. At the same time, introduce argon gas through the coaxial interface of the welding torch to obtain an arc additive manufacturing equipment and a wire feeding equipment ready for wire feeding. Step 4: Set the wire feeding speed, welding speed, arc voltage, weld width and weld height of the molten pool, pulsed peak current, pulsed base current, and number of pulse cycles in the arc additive manufacturing equipment and wire feeding equipment obtained in Step 3 to obtain an arc additive manufacturing equipment and a wire feeding equipment ready for arc additive manufacturing. Step 5: Start the arc additive manufacturing equipment and wire feeding equipment obtained in Step 4 for arc additive manufacturing. After each layer is deposited, remove the oxide layer, and strictly control the interlayer temperature. Subsequently, continue arc additive manufacturing deposition until each single-layer solid slice is stacked layer by layer according to the error-free path obtained in Step 1 to obtain a formed part. Step 6: In-situ statically air-cool the formed part obtained in Step 5 until room temperature to obtain the AZ80 magnesium alloy workpiece.

2. The AZ80 magnesium alloy arc additive manufacturing method based on the collaborative optimization of pulse period regulation and interlayer temperature according to claim 1, characterized in that, In Step 1, the slice type in the slicing process is a plane slice, and the path planning is a central line path.

3. A method for arc additive manufacturing of AZ80 magnesium alloy based on synergistic optimization of pulse period regulation and interlayer temperature, characterized in that, In Step 2, the preheating temperature of the magnesium alloy substrate is 130°C to 170°C.

4. A method for arc additive manufacturing of AZ80 magnesium alloy based on collaborative optimization of pulse period regulation and interlayer temperature according to claim 1, characterized in that, In Step 3, the diameter of the AZ80 magnesium alloy wire coil is 1.2 mm to 1.6 mm.

5. A method for arc additive manufacturing of AZ80 magnesium alloy based on synergistic optimization of pulse period regulation and interlayer temperature, characterized in that, In Step 3, the working distance is 10 mm to 13 mm.

6. A method for arc additive manufacturing of AZ80 magnesium alloy based on coordinated optimization of pulse period regulation and interlayer temperature, characterized in that, In Step 4, the wire feeding speed is 6000 mm / min to 8500 mm / min, the welding speed is 480 mm / min to 720 mm / min, the arc voltage is 10 V to 15 V, the set weld width of the molten pool is 5 mm to 12 mm, and the weld height is 1.8 mm to 2.2 mm.

7. A method for arc additive manufacturing of AZ80 magnesium alloy based on synergistic optimization of pulse period regulation and interlayer temperature according to claim 1, characterized in that, In Step 4, the pulsed peak current is 360 A to 390 A, the pulsed base current is 60 A to 90 A, and the number of pulse cycles is 3 to 12.

8. A method for arc additive manufacturing of AZ80 magnesium alloy based on coordinated optimization of pulse period regulation and interlayer temperature, characterized in that, The interlayer temperature described in Step 5 is controlled to be 130°C to 170°C.

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