A zinc-based feedstock powder additive manufacturing system and method of manufacturing thereof

Abstract

The present application relates to the technical field of zinc base powder additive manufacturing, and particularly relates to a zinc base powder additive manufacturing system and a manufacturing method thereof, the following steps: obtaining zinc base alloy powder, performing surface activation treatment through plasma jet; determining cold spraying process parameters based on oxygen content of the activated powder; performing cold spraying-laser composite deposition to form a dense blank on a substrate layer by layer; determining a metallurgical bonding state between the deposition, and triggering selective laser remelting to eliminate interface defects. The present application generates a composite oxide layer on the powder surface through Ar-mixed gas and 8-12kW power plasma jet treatment, can prevent excessive oxidation, and can improve powder activity, thereby laying a good foundation for subsequent spraying deposition.

Description

Technical Field

[0001] This invention relates to the field of zinc-based powder additive manufacturing technology, and specifically to a zinc-based powder additive manufacturing system and its manufacturing method. Background Technology

[0002] Zinc-based powder is a micron-sized particulate material with metallic zinc as its main component. It has long been widely used in the field of anti-corrosion coatings. It has the characteristics of gray metallic luster, high purity, and uniform particle size distribution. Its unique physicochemical properties, such as slight solubility in water, easy solubility in acids / alkalis, and strong reducing properties, make it occupy an important position in the field of anti-corrosion coatings. With the development of industrial technology, the application of zinc-based materials has gradually expanded to mechanical plating, life sciences, and new energy fields. Its core application scenarios include the production of zinc-rich primers. Through the cathodic protection effect of high-purity zinc powder, the service life of steel components in harsh marine and industrial atmospheric environments can be effectively extended. However, the traditional production process of zinc-based materials has the problems of high energy consumption and insufficient precision in force control. Summary of the Invention

[0003] This invention addresses the technical problems existing in the prior art by providing a zinc-based powder additive manufacturing system and its manufacturing method.

[0004] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for additive manufacturing of zinc-based powder, comprising the following steps: Zinc-based alloy powder was obtained and surface activated by plasma jet, wherein the powder surface temperature was monitored in real time and controlled within the range of 300-450℃ during the plasma treatment. Based on the activated powder having an oxygen content ≤0.3wt% and a surface roughness Ra of 0.5-1.2... Dynamically adjust the cold spraying process parameters; A cold spray-laser composite deposition process is performed to form a dense preform layer by layer on the substrate, with online defect monitoring performed immediately after each layer is deposited. The metallurgical bonding state between the deposited layers is determined, and selective laser remelting is triggered by acoustic emission signal characteristics to eliminate interface defects.

[0005] Preferably, the plasma activation treatment includes: employing a coaxial dual-channel Ar- Mixed gas, inner channel Ar, outer channel The plasma density is adjusted in real time using a Langmuir probe, with a concentration of 5%–8% and an RF power of 8–12 kW. The processing time is 50-100ms. During this time, the powder fluidization state is monitored by a high-speed camera to ensure that more than 90% of the powder passes through the plasma core region, generating nano-sized ZnO / Zn The composite oxide layer has a columnar crystal structure with a grain size of 20-50 nm.

[0006] Preferably, the dynamic adjustment of the cold spraying process parameters includes: establishing an oxygen content-process parameter mapping model: when the oxygen content is 0.1wt%, the gas pressure is 3-4MPa and the temperature is 400-500℃; when the oxygen content is 0.2-0.3wt%, the pressure is 4-5MPa and the temperature is 500-600℃; the ion velocity is calibrated in real time using a photon Doppler velocimeter with an error of ±5m / s; and the carrier gas contains... The ratio is linearly adjusted according to the oxygen content; for every 0.1% increase in oxygen content, Increase by 1%, while adding 0.1-0.3 vol% of C. To suppress secondary oxidation.

[0007] Preferably, the composite deposition process includes: during cold spray deposition, the spray gun is at a 60° angle to the substrate, the scanning speed is 200–400 mm / s, and the single-layer thickness is 100–150 mm. Laser remelting uses a coaxial annular spot with an inner diameter of 1 mm and an outer diameter of 3 mm. The pulse frequency is 10-50 kHz, the energy density is 5-8 J / cm², the spot overlap rate is 40%-60%, and the time interval between deposition and remelting is ≤50 ms. The interlayer temperature is maintained at 150-250℃ by using an infrared thermal imager.

[0008] Preferably, the triggering conditions for laser remelting are: ultrasonic testing showing interface porosity > 2%, center frequency 20MHz, focusing depth 0.1mm, microhardness gradient > 10%, nanoindentation test, load 10mN, and remelting parameters adaptively adjusted according to the defect type: high frequency 50kHz and low energy 5J / cm² for porosity defects, and low frequency 10kHz and high energy 8J / cm² for hardness gradient defects.

[0009] Preferably, the specific process for in-situ generation of the reinforcing phase is as follows: The coated powder undergoes a three-step reaction in the laser-acting region: a) break down: ; b) Zn oxidation: 2Zn+ ; c) Zn eutectic formation: Bi + Zn ; The generated nano The particles are uniformly distributed at the Zn grain boundaries, while the ZnO particles are dispersed within the grains.

[0010] Preferably, the The ALD coating process includes: the precursor uses Bi and The deposition temperature is 150-200℃, the number of cycles is 50-100, and the film thickness gradient is controlled: 5-10nm on the outer edge of the powder and 2-5nm near the core to form a core-shell structure.

[0011] Preferably, the specific method for constructing the gradient organization structure is as follows: Bottom layer: Laser energy density 5-8 J / cm², scanning speed 800 mm / s, forming equiaxed crystals; Middle layer: energy density 8-12 J / cm², velocity 500 mm / s, forming columnar crystals; Top layer: Energy density 12-15 J / cm², velocity 300 mm / s, to obtain nanocrystals; Transition zones are set between each floor.

[0012] Preferably, the optimized composition of the zinc-based powder includes: Zn-5Al-3Mg-0.5 In Al, Al-Mg It exists in the form of intermetallic compounds, with an average size of 1-3. Mg is dissolved in the Zn matrix with a solid solubility of 4.5-5.5 wt%, the powder sphericity is ≥95%, and the hollow powder rate is <0.1%.

[0013] The present invention also provides a zinc-based powder additive manufacturing system, comprising: Plasma activation: includes an annular electrode nozzle unit and a powder delivery unit. The annular electrode nozzle unit is equipped with an emission spectrometer to monitor the plasma composition in real time. The carrier gas flow rate of the powder delivery unit is 10-20 L / min, and the powder mass flow rate is 50-200 g / min. Cold spray-laser composite nozzle: includes a cold spray nozzle unit and a laser unit. The throat diameter of the cold spray nozzle unit is 2mm and the expansion ratio is 3:1. The laser unit includes a fiber laser and an integrated galvanometer scanning unit. Online testing: including ultrasonic testing instruments and component analyzers.

[0014] The beneficial effects of this invention are: this invention utilizes Ar- The mixed gas and 8-12kW plasma jet treatment generate a composite oxide layer on the powder surface, which can prevent over-oxidation, improve powder activity, and lay a good foundation for subsequent spraying and deposition. The carrier gas is dynamically adjusted according to the oxygen content of the powder. By combining a gas pressure of 3-5 MPa, a temperature of 400-600℃, and a particle velocity of 600-800 m / s, high-quality deposition can be achieved for powders in different states, improving process adaptability and stability. A 5-10 nm layer is deposited on the powder surface through atomic layer deposition. Nanofilm, 3Zn+ ions are generated under laser irradiation The reaction generates in-situ nano-Bi particles for dispersion reinforcement, which significantly improves the strength and toughness of the material. The laser energy density is increased layer by layer from the substrate to the top layer, forming a grain size gradient, so that different parts of the material have suitable mechanical properties and optimize the overall performance. Attached Figure Description

[0015] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0018] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0019] like Figure 1 This embodiment provides a zinc-based powder additive manufacturing method, comprising the following steps: Zinc-based alloy powder was obtained and surface activated by plasma jet, wherein the powder surface temperature was monitored in real time and controlled within the range of 300-450℃ during the plasma treatment. Based on the activated powder having an oxygen content ≤0.3wt% and a surface roughness Ra of 0.5-1.2... Dynamically adjust the cold spraying process parameters; A cold spray-laser composite deposition process is performed to form a dense preform layer by layer on the substrate, with online defect monitoring performed immediately after each layer is deposited. The metallurgical bonding state between the deposited layers is determined, and selective laser remelting is triggered by acoustic emission signal characteristics to eliminate interface defects.

[0020] Furthermore, the plasma activation treatment includes: employing a coaxial dual-channel Ar- Mixed gas, inner channel Ar, outer channel The plasma density is adjusted in real time using a Langmuir probe, with a concentration of 5%–8% and an RF power of 8–12 kW. The processing time is 50-100ms. During this time, the powder fluidization state is monitored by a high-speed camera to ensure that more than 90% of the powder passes through the plasma core region, generating nano-sized ZnO / Zn The composite oxide layer has a columnar crystal structure with a grain size of 20-50 nm.

[0021] Furthermore, the dynamic adjustment of the cold spraying process parameters includes: establishing an oxygen content-process parameter mapping model: when the oxygen content is 0.1wt%, the gas pressure is 3-4MPa and the temperature is 400-500℃; when the oxygen content is 0.2-0.3wt%, the pressure is 4-5MPa and the temperature is 500-600℃; the ion velocity is calibrated in real time using a photon Doppler velocimeter with an error of ±5m / s; and the carrier gas... The ratio is linearly adjusted according to the oxygen content; for every 0.1% increase in oxygen content, Increase by 1%, while adding 0.1-0.3 vol% of C. To suppress secondary oxidation.

[0022] It should be noted that the surface activation of zinc-based alloy powder (Zn-5Al-3Mg) is performed using plasma jets. The core principle is as follows: Plasma activation mechanism: using Ar- Mixed gas ( High-temperature plasma (electron temperature 1-5 eV) is generated at 8-12 kW power (5%–8%), causing nano-sized ZnO / ZnO to form on the powder surface. A composite oxide layer (10-30 nm thick) reduces the critical deposition rate of particles during cold spraying (from the conventional 600 m / s to 500 m / s), while... The reducing effect controls the oxygen content of the powder to 0.3 wt%; Dynamic adjustment of cold spraying parameters: based on the oxygen content and surface morphology of the activated powder (Ra 0.5-1.2). A mapping relationship was established between gas pressure (3-5 MPa), temperature (400-600℃), and particle velocity (600-800 m / s). When the oxygen content increased by 0.1%, the carrier gas... The proportion is increased by 1% to compensate for the loss of deposition efficiency caused by oxidation.

[0023] Furthermore, the composite deposition process includes: during cold spray deposition, the spray gun is at a 60° angle to the substrate, the scanning speed is 200–400 mm / s, and the single-layer thickness is 100–150 mm. Laser remelting uses a coaxial annular spot with an inner diameter of 1 mm and an outer diameter of 3 mm. The pulse frequency is 10-50 kHz, the energy density is 5-8 J / cm², the spot overlap rate is 40%-60%, and the time interval between deposition and remelting is ≤50 ms. The interlayer temperature is maintained at 150-250℃ by using an infrared thermal imager.

[0024] Furthermore, the triggering conditions for laser remelting are as follows: ultrasonic testing shows an interface porosity > 2%, a center frequency of 20 MHz, a focusing depth of 0.1 mm, a microhardness gradient > 10%, nanoindentation testing, a load of 10 mN, and the remelting parameters are adaptively adjusted according to the defect type: a high frequency of 50 kHz and a low energy of 5 J / cm² are used for porosity defects, and a low frequency of 10 kHz and a high energy of 8 J / cm² are used for hardness gradient defects.

[0025] It should be noted that the core principles of cold spray-laser composite deposition include: Cold spray deposition: Powder is accelerated to 600-800 m / s by a supersonic airflow (Mach 2.5-3.0), and after impacting the substrate, it undergoes plastic deformation to form a dense layer (single layer thickness 100-150 mm). Its bonding strength depends on the conversion of particle kinetic energy into thermal energy (local temperature rise of 200-300℃) and the dynamic recrystallization of Zn / Al / Mg (grain boundary size 0.5-2). ); Laser remelting triggering conditions: Interface porosity is detected using 20MHz ultrasonic testing (resolution 0.1mm). When porosity is >2%, pulsed laser (1064nm, 5-8J / cm²) is triggered for selective remelting. The laser energy causes selective remelting in the interface micro-regions (depth 50-100mm). When the temperature is raised above the melting point of Zn (419.5℃), the pores are filled through the Marangoni effect (filling rate >95%), while eliminating the hardness gradient (gradient difference is reduced from >10% to <3%).

[0026] Furthermore, the specific process of in-situ generation of the reinforcing phase is as follows: The coated powder undergoes a three-step reaction in the laser-acting region: d) break down: (800-1000℃); e) Zn oxidation: 2Zn+ (Exothermic reaction); f) Zn eutectic formation: Bi + Zn (Eutectic point 254℃); The generated nano The particles are uniformly distributed at the Zn grain boundaries, while the ZnO particles (20-50 nm) are dispersed within the grains.

[0027] Furthermore, the aforementioned The ALD coating process includes: the precursor uses Bi and The deposition temperature is 150-200℃, the number of cycles is 50-100, and the film thickness gradient is controlled: 5-10nm on the outer edge of the powder and 2-5nm near the core to form a core-shell structure.

[0028] Furthermore, the specific construction method of the gradient organization structure: Bottom layer: Laser energy density 5-8 J / cm², scanning speed 800 mm / s, forming equiaxed crystals (50-100). ); Middle layer: Energy density 8-12 J / cm², velocity 500 mm / s, forming columnar crystals (20-50). ); Top layer: Energy density 12-15 J / cm², velocity 300 mm / s, obtaining nanocrystals (10⁻²⁰ J / cm²). ); A transition zone is set between each layer (energy density gradually changes, gradient change rate ≤ 2J / cm² / mm).

[0029] It is important to explain the in-situ enhancement and gradient structure construction: In-situ reaction: Add 0.5-2wt% (ALD coating, 5-10nm thick) undergoes an exothermic reaction under laser irradiation. This process generates nano-sized Bi particles (50-100 nm) and ZnO particles (20-50 nm). The particles are distributed at the grain boundaries, which inhibit grain boundary slip through the pinning effect (creep rate reduced by 50%), and ZnO particles strengthen the grains (hardness increased by 20-30 HV). Gradient structure formation mechanism: From the substrate to the top layer, the laser energy density gradually increases from 5 J / cm² to 15 J / cm², resulting in differences in thermal accumulation effects: the bottom layer forms equiaxed crystals at low temperatures (50-100 J / cm²). High temperature at the top layer promotes nanocrystal growth (10-20). The transition zone is controlled by a gradient change rate of ≤2J / cm² / mm to avoid thermal stress concentration (residual stress <50MPa, measured by XRD).

[0030] Furthermore, the composition optimization of the zinc-based powder includes: Zn-5Al-3Mg-0.5 In Al, Al-Mg It exists in the form of intermetallic compounds, with an average size of 1-3. Mg is dissolved in the Zn matrix with a solid solubility of 4.5-5.5 wt%, the powder sphericity is ≥95%, and the hollow powder rate is <0.1% (detected by X-ray tomography).

[0031] The present invention also provides a zinc-based powder additive manufacturing system, comprising: Plasma activation: includes an annular electrode nozzle unit and a powder delivery unit. The annular electrode nozzle unit is equipped with an emission spectrometer to monitor the plasma composition in real time. The carrier gas flow rate of the powder delivery unit is 10-20 L / min, and the powder mass flow rate is 50-200 g / min. Cold spray-laser composite nozzle: includes a cold spray nozzle unit and a laser unit. The throat diameter of the cold spray nozzle unit is 2mm and the expansion ratio is 3:1. The laser unit includes a fiber laser and an integrated galvanometer scanning unit. Online testing: including ultrasonic testing instruments and component analyzers.

[0032] It should be noted that the powder composition is: Zn-5Al-3Mg-0.5 In Al, Al-Mg It exists in the form of intermetallic compounds, which improves high-temperature stability (80% strength retention at 300℃). The solid solubility of Mg is 4.5-5.5wt%, which improves the matrix strength through solid solution strength (yield strength is increased by 40MPa).

[0033] It should be noted that the system integration principle is as follows: plasma activation is monitored in real time via OES. (750nm) and (656nm) spectral line intensity, feedback adjustment power (accuracy ±0.5kW), cold spray-laser composite nozzle adopts coaxial design, time synchronization accuracy ±1ms, online ultrasonic detection through acoustic impedance matching layer (ZnTe, thickness) Increase the signal-to-noise ratio by >20dB.

[0034] Example 2 This embodiment provides a zinc-based powder additive manufacturing method, including the following steps: Plasma activation process: using Ar-6% Mixed gas, 10kW power processing for 80ms: these parameters can generate appropriate amounts of nano-sized ZnO / Zn on the surface of zinc-based alloy powder. The composite oxide layer effectively controls the oxygen content of the powder at a low level, which improves the surface activity of the powder while avoiding excessive oxidation that could affect subsequent processing. Cold spraying stage: 4MPa gas pressure, 500℃ temperature, 700m / s particle velocity, and 6% [unspecified component]. The proportions are optimized to ensure that the activated powder can be deposited on the substrate in a good state. Appropriate process parameters ensure the uniformity and stability of powder deposition, forming a preliminary deposition layer with a certain density. Then, a pulsed laser with a wavelength of 1064nm, a pulse width of 20ns, and an energy density of 6J / cm² is used for remelting, which effectively improves the internal structure of the deposition layer and enhances the interlayer metallurgical bonding.

[0035] Atomic layer deposition: coating an 8nm layer onto the powder surface The addition amount is 1wt%, which generates nano-Bi particles in situ under the action of laser, playing a role in dispersion and strengthening. The final part exhibits excellent comprehensive performance, with a density of 99.2%, a tensile strength of 280MPa, a hardness of 115HV, and an interfacial bonding strength of 210MPa.

[0036] Example 3 This embodiment provides a zinc-based powder additive manufacturing method, including the following steps: Plasma activation process: using Ar-8% Mixed gas, 12kW power processing 50ms, higher power and The ratio increases the degree of surface activation of the powder; Cold spraying stage: 5MPa gas pressure, 600℃ temperature, 800m / s particle velocity, and 7% [unspecified element]. The proportion is such that a pulsed laser with a wavelength of 1064nm, a pulse width of 10ns, and an energy density of 8J / cm² is used for remelting.

[0037] Atomic layer deposition: coating a powder surface with a 10nm layer. With an addition amount of 2wt%, nano-Bi particles are generated in situ under laser irradiation, which play a role in dispersion and strengthening. The final part exhibits excellent comprehensive performance, with a density of 99.5%, a tensile strength of 320MPa, a hardness of 135HV, and an interfacial bonding strength of 240MPa.

[0038] Example 4 This embodiment provides a zinc-based powder additive manufacturing method, including the following steps: Plasma activation process: using Ar-5% Mixed gas, processed in 100ms with 8kW power; Cold spraying stage: 3MPa gas pressure, 400℃ temperature, 600m / s particle velocity, and 5% [unspecified element]. The proportion is such that a pulsed laser with a wavelength of 1064nm, a pulse width of 10ns, and an energy density of 15J / cm² is used for remelting.

[0039] Atomic layer deposition: coating 5nm layers onto the powder surface With an addition amount of 0.5wt%, nano-Bi particles are generated in situ under laser irradiation, which play a role in dispersion and strengthening. The final part exhibits excellent comprehensive performance, with a density of 99.1%, a tensile strength of 300MPa, a hardness of 125HV, and an interfacial bonding strength of 190MPa.

[0040] Based on the table above, it was found that the hardness of Example 3 was 17% higher than that of Example 2, which shows the dispersion strengthening effect of the nano-Bi particles. Example 4 achieved a synergistic improvement in strength and toughness.

[0041] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0042] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0043] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0044] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0045] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0046] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0047] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for additive manufacturing of zinc-based powder, characterized in that, Includes the following steps: Zinc-based alloy powder was obtained and surface-activated using plasma jet. Based on the oxygen content of the activated powder, an oxygen content-process parameter mapping relationship was established to dynamically determine the cold spraying process parameters. Among them, for every 0.1% increase in oxygen content, the proportion of H2 in the carrier gas increases linearly by 1%. A dense preform is formed layer by layer on the substrate by performing cold spray-laser composite deposition; Determine the metallurgical bonding state between deposits and trigger selective laser remelting to eliminate interface defects; The composite deposition process includes: cold spray deposition of a single layer with a thickness of 100-150 mm. Immediately scan the deposited layer with a pulsed laser at an energy density of 5–8 J / cm².

2. The zinc-based powder additive manufacturing method according to claim 1, characterized in that, The plasma activation treatment uses Ar- Mixed gas, With a concentration of 5%–8%, a power of 8–12 kW, and a processing time of 50–100 ms, nano-sized ZnO / ZnO is generated on the powder surface. The composite oxide layer has a thickness of 10-30 nm.

3. The zinc-based powder additive manufacturing method according to claim 1, characterized in that, The determination of cold spraying process parameters includes: gas pressure 3-5 MPa, temperature 400-600℃, particle velocity 600-800 m / s, and adjustment of the carrier gas according to the oxygen content of the powder. The proportion of H2 in the carrier gas is linearly adjusted according to the oxygen content of the powder. For every 0.1% increase in the oxygen content of the powder, the proportion of H2 in the carrier gas increases by 1%.

4. The zinc-based powder additive manufacturing method according to claim 1, characterized in that, The triggering conditions for laser remelting are: ultrasonic testing shows that the interface porosity is >2% and the microhardness gradient is >10%.

5. The zinc-based powder additive manufacturing method according to claim 1, characterized in that, It also includes in-situ generation of reinforcing phase: adding 0.5-2 wt% of [a specific ingredient] to the powder. A reaction occurs when laser light is applied: 3Zn+ This generates nano-Bi particles for dispersion reinforcement.

6. The zinc-based powder additive manufacturing method according to claim 5, characterized in that, The The addition method is: coating the powder surface through atomic layer deposition. Nanofilms with a thickness of 5-10 nm.

7. The zinc-based powder additive manufacturing method according to claim 1, characterized in that, This also includes constructing a gradient tissue structure: adding laser energy density 5 layer by layer from the substrate to the top layer. 15 J / cm², forming a grain size gradient.

8. The zinc-based powder additive manufacturing method according to claim 1, characterized in that, The composition of the zinc-based powder is: Zn-5Al-3Mg-0.5 The balance is Zn, and the powder sphericity is ≥95%.

9. A zinc-based powder additive manufacturing system applied to the zinc-based powder additive manufacturing method as described in any one of claims 1-8, characterized in that, include: Plasma activation: integrated RF power supply and annular electrode nozzle; Cold spray-laser composite nozzle: enables coaxial synchronous deposition and remelting; Online ultrasonic testing equipment: including ultrasonic testing equipment and component analyzer.

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