LDED in-situ atmosphere reaction method and apparatus based on ultrasonic compounding

Abstract

An LDED in-situ atmosphere reaction method based on ultrasonic compounding, comprising the following steps: designing a reaction of a forming material and atmosphere components and an area; preparing a powder material; configuring a forming substrate (100), an atmosphere mixing device (400), a powder conveying device (500), an ultrasonic device, and a laser forming device to perform forming processing; controlling the output amount of a protective atmosphere and a reaction atmosphere, and the amount of powder conveying of the powder conveying device (500); melting the material by the laser forming device to form a molten pool (110), and applying ultrasonic waves on the molten pool (110); and moving laser on the basis of a trajectory until a part is formed. By designing a reaction of powder and an atmosphere, reinforcing components are synthesized to enhance a material; ultrasonic waves enhance a reaction of the atmosphere and a melt; the reinforcing components are uniformly distributed; an atmosphere supply amount and the ultrasonic effect are controlled to adjust the atmosphere synthesis reaction effect and the content of components; and the design distribution-based spatial forming of the material components, the microstructure and the performance of a part is implemented in light of a deposition trajectory, thereby achieving dual optimization and enhancement of the structure and the material. The present invention further relates to an LDED in-situ atmosphere reaction apparatus based on ultrasonic compounding.

Description

A LDED in-situ atmosphere reaction method and equipment based on ultrasonic compounding Technical Field

[0001] The present application relates to the field of additive manufacturing technology, and in particular to an LDED in-situ atmosphere reaction method and equipment based on ultrasonic compounding. Background Art

[0002] Laser Directed Energy Deposition (LDED) is a relatively efficient laser additive manufacturing technology that can quickly deposit and form metal parts, but its disadvantage is that the dimensional accuracy and surface quality of the formed parts are poor. In addition, due to the extremely high forming speed of LDED, the forming temperature of the entire part is high, and its internal stress is large, which is prone to defects such as cracking. Furthermore, due to the coarse grains and the large number of pore defects, the forming performance of its parts is poor compared to laser additive manufacturing technologies such as laser selective melting. Therefore, it is necessary to improve some technologies and methods to gain performance of the forming material.

[0003] Summary of the Invention

[0004] The present application aims to address at least one of the technical problems existing in the prior art. To this end, the present application proposes an in-situ atmosphere reaction method for LDED based on ultrasonic compounding. This method can achieve spatially designed distribution of component composition, microstructure, and properties by controlling the reaction action, component content, and deposition trajectory, thereby achieving dual optimization gains in both structure and material.

[0005] The present application also proposes a device using the above-mentioned LDED in-situ atmosphere reaction method based on ultrasonic compounding.

[0006] According to the first embodiment of the present application, the LDED in-situ atmosphere reaction method based on ultrasonic compounding includes the following steps:

[0007] Design of chemical reaction synthesis of LDED forming materials and atmosphere components;

[0008] Complete the design of the three-dimensional structure of the part based on the difference between the forming material and the material after reaction forming, and determine the area for ultrasonic composite atmosphere reaction;

[0009] adding powder material into the powder delivery device;

[0010] A forming substrate, an atmosphere mixing device, a powder conveying device, an ultrasonic device and a laser forming device are configured to perform forming processing;

[0011] The output of the protective atmosphere and the reaction atmosphere is controlled so that the atmosphere mixing device is suitable for outputting a mixed atmosphere with a specific component content; the powder conveying device is controlled to output a specific amount of powder material onto the forming substrate;

[0012] The laser nozzle of the laser forming device outputs laser light to melt the powder material at the focus to form a molten pool, and an ultrasonic device acts on the molten pool to make the melt in the molten pool contact with the mixed atmosphere to generate an atmosphere synthesis reaction;

[0013] The laser nozzle is controlled to move along a predetermined trajectory until the part is completely formed.

[0014] The ultrasonically compounded in-situ atmosphere reaction method for LDED (Laminated Metal Elastomer) according to the first embodiment of the present application has at least the following beneficial effects: a chemical reaction is designed between the LDED forming material and the atmosphere components, allowing certain elements in the forming material to react with certain components in the transport atmosphere to form strengthening components. Ultrasonic waves are simultaneously applied to the molten pool, stirring the atmosphere reaction with ultrasound to ensure more complete interaction between the atmosphere and the molten metal, enhancing the reaction effect, increasing the reaction rate and making it more thorough, generating more strengthening components. Furthermore, ultrasonic stirring ensures a more uniform distribution of strengthening components, thereby enhancing their strengthening effect. Compared to existing technologies, this "ultrasonic compound atmosphere reaction" can achieve spatially designed distribution of part material composition, microstructure, and properties by controlling the reaction action, component content, and deposition trajectory, achieving dual structural and material optimization gains.

[0015] According to the ultrasonic compound-based in-situ atmosphere reaction method for LDED described in the embodiment of the first aspect of the present application, the design of LDED forming materials and atmosphere components includes the design of component types and component contents.

[0016] According to the ultrasonic compound-based in-situ atmosphere reaction method of LDED described in the embodiment of the first aspect of the present application, the reaction atmosphere is selected according to the composition of the powder material, the powder material is an original alloy powder suitable for atmosphere reaction, or the powder material is a mixed modified powder containing atmosphere reaction elements.

[0017] According to the ultrasonic compound-based in-situ atmosphere reaction method of LDED described in the embodiment of the first aspect of the present application, the powder material is a mixed modified powder containing atmosphere reaction elements, and the preparation method of the mixed modified powder includes: adding the original powder to the modified powder in a certain mass ratio, first performing ultrasonic dispersion, and then ball milling to obtain a fully mixed mixed modified powder.

[0018] According to the first aspect of the present application, the LDED in-situ atmosphere reaction method based on ultrasonic compounding is described in the embodiment, wherein the protective atmosphere is Ar;

[0019] And / or the powder material is an original alloy powder suitable for atmosphere reaction, the original alloy powder is titanium alloy powder, and the reaction atmosphere is N2; or the original alloy powder is aluminum alloy powder, and the reaction atmosphere is O2;

[0020] And / or the powder material is a mixed modified powder containing atmosphere reaction elements, the mixed modified powder includes original powder and modified powder mixed in a certain mass ratio, the original powder is GH5188 high temperature alloy, and the modified powder is pure titanium Ti powder.

[0021] According to the ultrasonic compound-based LDED in-situ atmosphere reaction method described in the first aspect of the embodiment of the present application, two atmosphere mixing devices are provided, one of which is connected to the powder conveying device to convey the powder material to the forming substrate through the mixed atmosphere, and the other atmosphere mixing device cooperates with the laser forming device to form a protective gas barrier at the laser nozzle.

[0022] According to the ultrasonic composite LDED in-situ atmosphere reaction method described in the first aspect embodiment of the present application, the process parameters are adjusted before the forming process. The process parameters include laser power, scanning spacing, scanning speed, layer thickness, powder supply speed, flow rate of protective atmosphere and reaction atmosphere or at least one of ultrasonic working parameters.

[0023] According to the in-situ atmosphere reaction method of LDED based on ultrasonic compounding described in the embodiment of the first aspect of the present application, during the forming process, the start timing of the atmosphere mixing device and the ultrasonic device is controlled to perform at least one of ultrasonic action forming, atmosphere reaction forming, ultrasonic compound atmosphere reaction forming, or LDED forming on the part;

[0024] During the forming process, at least one of the content of the reaction atmosphere, the content of the powder material or the ultrasonic working parameters is adjusted in real time.

[0025] According to the second aspect of the present application, the LDED in-situ atmosphere reaction device based on ultrasonic compounding includes: using the LDED in-situ atmosphere reaction method based on ultrasonic compounding described in the first aspect of the present application.

[0026] It is not difficult to understand that the LDED in-situ atmosphere reaction equipment based on ultrasonic compounding in the second embodiment of the present application has the technical effect of the LDED in-situ atmosphere reaction method based on ultrasonic compounding in the first embodiment mentioned above, and therefore will not be repeated.

[0027] According to the second aspect of the present application, the LDED in-situ atmosphere reaction device based on ultrasonic compounding comprises:

[0028] An atmosphere mixing device, comprising a plurality of gas input components and an atmosphere mixer, wherein the atmosphere mixer is connected to at least some of the gas input components;

[0029] An ultrasonic device, comprising an ultrasonic generator, an ultrasonic stirrer and an ultrasonic vibration platform, wherein the ultrasonic generator is connected to the ultrasonic stirrer and the ultrasonic vibration platform respectively;

[0030] A laser forming device, comprising a driving component, a laser and a laser nozzle, wherein the laser nozzle is connected to the laser, and the driving component is used to drive the laser nozzle to move along a predetermined trajectory;

[0031] Powder conveying device;

[0032] A forming substrate is arranged on the ultrasonic vibration platform, and the ultrasonic stirrer, the powder conveying device, the laser nozzle and the atmosphere mixing device act on the material of the forming substrate.

[0033] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present application is further described below with reference to the accompanying drawings and embodiments;

[0035] FIG1 is a system schematic diagram of an embodiment of the present application.

[0036] Reference numerals:

[0037] 100, forming substrate; 110, molten pool;

[0038] 210. Ultrasonic generator; 220. Ultrasonic stirrer; 230. Ultrasonic vibration platform;

[0039] 310, laser; 320, laser nozzle;

[0040] 400, atmosphere mixing device; 410, gas input component; 420, atmosphere mixer;

[0041] 500. Powder conveying device. DETAILED DESCRIPTION

[0042] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0043] In the description of this application, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0044] In the description of this application, "several" means one or more, "more" means at least two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The terms "first" and "second" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly specifying the number or order of the technical features.

[0045] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense. Technical personnel in the relevant technical field can reasonably determine the specific meanings of the above terms in this application after combining the specific content of the technical solution.

[0046] It is understood that laser directed energy deposition (DED) is a major technical approach in laser additive manufacturing. This technology uses a laser beam as the primary energy source. Based on the 3D model slice data, the laser nozzle 320 motion trajectory is generated. Deposition parameters are set to focus the metal powder and the laser light onto the same focal point, forming a molten pool 110. The nozzle's motion trajectory and the interaction between the laser and the metal powder ultimately melt and solidify the metal powder into a solid part.

[0047] 1 , the in-situ atmosphere reaction method for LDED based on ultrasonic compounding according to the first embodiment of the present application relates to an ultrasonic compounding laser directed energy deposition technology in the field of composite laser additive manufacturing technology, and more particularly to an in-situ atmosphere reaction synthesis strengthening method for LDED based on ultrasonic compounding. The in-situ atmosphere reaction method for LDED based on ultrasonic compounding comprises the following steps:

[0048] Design of chemical reaction synthesis of LDED forming materials and atmosphere components;

[0049] Complete the design of the three-dimensional structure of the part based on the difference between the forming material and the material after reaction forming, and determine the area for ultrasonic composite atmosphere reaction;

[0050] A forming substrate 100, an atmosphere mixing device 400, a powder conveying device 500, an ultrasonic device and a laser forming device are configured to perform forming processing;

[0051] Adding powder material to the powder delivery device 500;

[0052] Among them, the output of the protective atmosphere and the reaction atmosphere is controlled so that the atmosphere mixing device 400 is suitable for outputting a mixed atmosphere with a specific component content; the powder conveying device 500 is controlled to output a specific amount of powder material to the forming substrate 100;

[0053] The laser nozzle 320 of the laser forming device outputs laser light to melt the powder material at the focus point to form a molten pool 110. The ultrasonic device acts on the molten pool 110 to make the melt in the molten pool 110 contact with the mixed atmosphere to cause an atmosphere synthesis reaction.

[0054] The laser nozzle 320 is controlled to move along a predetermined trajectory until the part is completely formed.

[0055] It is understood that in the laser directed energy deposition system of the related art, during the cumulative forming process along the trajectory of the laser nozzle 320, the metal powder is generally transported to the laser focus point by argon gas. At the same time, the argon gas acts as a protective atmosphere, filling the forming cavity or forming a gas barrier near the forming nozzle, preventing oxidizing gases in the atmosphere from reacting with the metal melt and causing metal oxidation, which can negatively affect the material properties. Therefore, in some embodiments of the present application, the composition of the powder material formed by LDED and the composition of the gas used to transport the powder are designed so that the two react chemically under the action of the laser to generate certain material components that have a positive effect on the raw material properties, thereby enhancing the material properties.

[0056] It should be noted that ultrasound can generate cavitation, acoustic streaming, and vibration effects in liquid metal, stirring the melt. Therefore, ultrasound is used to enhance the chemical reaction between the metal material and the atmosphere within the molten pool 110 during metal laser directed energy deposition (LDED), thereby uniformly distributing the composition of the composite material. Ultrasound also has the effects and benefits of LDED forming, such as grain refinement, uniform composition, uniform temperature field, stress reduction, temperature gradient reduction, and disruption of preferred grain orientation.

[0057] In some embodiments, the method of configuring the forming substrate 100, the atmosphere mixing device 400, the powder conveying device 500, the ultrasonic device and the laser forming device includes: setting the deposition control program, mainly setting the switching timing of the reaction gas delivery and the switching timing of the ultrasonic device, that is, turning on the ultrasonic device and the gas delivery switch when the LDED forming "ultrasonic composite atmosphere reaction" area, and at the same time, the gas delivery flow rate, ultrasonic amplitude and other parameters can be set or controlled in real time. After completing the program configuration, the program is imported into the controller, and after the program is tested and run correctly, the forming substrate 100 is installed, the device is turned on, and the atmosphere mixing device 400, the powder conveying device 500, the ultrasonic device (acting on the LEDE molten pool 110), and the laser forming device (including the laser nozzle 320, the laser 310, the controller, the driving component for driving the main shaft movement of the laser nozzle 320, the water cooling device, etc.) are configured, and then the forming process is performed.

[0058] In some embodiments, the laser light emitted from the laser nozzle 320 melts the metal powder at the focus to form a molten pool 110. The metal melt in the molten pool 110 contacts the mixed atmosphere to produce an atmosphere synthesis reaction to generate a strengthening substance. The ultrasonic device acts on the molten pool 110, and the stirring effects such as cavitation and acoustic streaming enhance the convection in the molten pool 110, thereby strengthening the contact between the melt and the mixed atmosphere and improving the efficiency of the reaction. In addition, the acoustic streaming effect makes the metal melt tend to be uniform, further homogenizing the distribution of the synthetic strengthening substance, making its subsequent strengthening effect more uniform, and improving the consistency of material properties.

[0059] Simultaneously, the driver drives the laser nozzle 320 along a pre-programmed trajectory, melting and solidifying each layer into the designed part. Finally, when the part reaches the non-atmosphere reactive zone, the mixed atmosphere output stops, and the ultrasonic device can be programmed to turn on and off as needed.

[0060] Referring to Figure 1 , the ultrasonically compounded in-situ atmosphere reaction method for LDED (Laminated Metal Elastomer) in a first embodiment of the present application employs a chemical reaction design between the LDED forming material and atmosphere components, allowing certain elements in the forming material to react with certain components in the transport atmosphere to form strengthening components. Simultaneously, ultrasound is applied to the molten pool 110, stirring the atmosphere with ultrasound to ensure more complete interaction between the atmosphere and the molten metal, enhancing the reaction effect, increasing the reaction rate and making it more thorough, thereby generating more strengthening components. Furthermore, ultrasonic stirring ensures a more uniform distribution of the strengthening components, thereby enhancing their strengthening effect. Compared to existing technologies, this "ultrasonic compounded atmosphere reaction" can achieve spatially designed distribution of part material composition, microstructure, and properties by controlling the reaction action, component content, and deposition trajectory, achieving dual structural and material optimization gains.

[0061] It can be understood that the present invention combines ultrasonic composite stirring, material and atmosphere reaction, and material component three-dimensional structure design and customization to optimize the LDED forming microstructure, composition, material structure performance and other aspects.

[0062] In some embodiments of the present application, the design of the LDED forming material and atmosphere components includes the design of the component types and component contents. It is understood that the LDED forming material and atmosphere components are designed for chemical reaction synthesis, so that certain elements in the forming material react with certain components in the delivery atmosphere to synthesize strengthening components such as metal ceramics.

[0063] In some embodiments, the material composition and microstructure of laser directed energy deposition (LDED) parts are spatially designed based on the material properties and microstructural characteristics of the material after the "ultrasonic combined atmosphere reaction." The LDED program is then configured to utilize the "ultrasonic combined atmosphere reaction" only in certain designed spatial forming areas to customize the composition and crystal structure of the part. This spatial structure-material design and forming process allows for dual structural and material optimization of part performance and spatial stress distribution characteristics.

[0064] In some embodiments of the present application, the reaction atmosphere is selected according to the composition of the powder material, and the powder material is an original alloy powder suitable for atmosphere reaction, or the powder material is a mixed modified powder containing atmosphere reaction elements. In some embodiments, when the LDED forming material and the atmosphere component are designed for chemical reaction synthesis, the conveying gas component needs to be designed according to the basic material component of LDED forming. For example, if the titanium alloy contains Ti, nitrogen can react to form titanium nitride, a strengthening component. If the aluminum alloy contains Al, it can react with oxygen to form aluminum oxide. If there is no component in the basic material component that can react with gas, or in order not to destroy the original material components, certain powder particles that can react with atmosphere, such as pure titanium, pure zirconium, etc., can be added to the basic forming material component according to the actual reaction requirements, and the reaction atmosphere can be oxygen, nitrogen, etc.

[0065] In some embodiments of the present application, the preparation method of the mixed modified powder includes: adding the original powder to the modified powder in a certain mass ratio, first performing ultrasonic dispersion, and then ball milling to obtain a fully mixed mixed modified powder, which can then be added to the powder conveying device 500.

[0066] In some embodiments of the present application, the protective atmosphere is Ar, and other inert gases may also be used as the protective atmosphere.

[0067] In some embodiments of the present application, the original alloy powder is titanium alloy powder, and the reaction atmosphere is N2. In other embodiments of the present application, the original alloy powder is aluminum alloy powder, and the reaction atmosphere is O2.

[0068] It can be understood that during the forming process, the protective atmosphere Ar and the forming reaction atmosphere (nitrogen, oxygen, etc.) are output from the storage device to the mixing chamber for mixing, and a flow valve is installed between the storage device and the mixing chamber to control the flow of the two gases to control the content of the mixed atmosphere components.

[0069] In some embodiments of the present application, the mixed modified powder includes original powder and modified powder mixed in a certain mass ratio, the original powder is GH5188 high temperature alloy, and the modified powder is pure titanium Ti powder.

[0070] In some embodiments, the modified powder includes original powder: GH5188 high-temperature alloy powder and modified powder: pure titanium Ti powder. Before forming, the GH5188 high-temperature alloy powder and the pure titanium Ti powder are mixed in a certain mass ratio, first ultrasonically dispersed, and then ball milled for sufficient mixing. The obtained mixed modified powder is added to the powder conveying device 500.

[0071] It can be understood that the Ti element + N2 in GH5188 high-temperature alloy + pure titanium Ti reacts under the action of laser to generate titanium nitride TiN, which can enhance the mechanical properties of the base material such as tensile strength and microhardness, and refine the microstructure.

[0072] It is understandable that the example of GH5188 high-temperature alloy is only one specific embodiment and does not specifically refer to a specific application object. The specific application objects of this patent are very broad.

[0073] In some embodiments of the present application, two atmosphere mixing devices 400 are provided, one of which is connected to the powder conveying device 500 to convey the powder material to the forming substrate 100 through the mixed atmosphere, and the other atmosphere mixing device 400 cooperates with the laser forming device to form a protective gas barrier at the laser nozzle 320. It is understood that two atmosphere mixing devices 400 are provided, one is connected to the powder conveying device 500, and the other is arranged near the laser forming device. When in use, the prepared metal powder material is added to the storage chamber of the powder conveying device 500. The prepared metal powder material mainly refers to the original metal powder without adjusting the composition and the modified powder with the addition of reactive components. After the mixed atmosphere is introduced, the powder is transported to the focus of the laser by gas conveying.

[0074] In some embodiments, the modified powder mainly refers to a mixture of metal powders added with reaction components in a certain mass percentage, preferably by ultrasonic dispersion and then ball milling to achieve a sufficiently uniform mixing of the two.

[0075] In other embodiments, the modified powder may also be prepared from other metal powders having strengthening effects through a similar mixing method.

[0076] In some embodiments of the present application, process parameters are adjusted before forming. The process parameters include at least one of laser power, scanning pitch, scanning speed, layer thickness, powder supply rate, flow rates of the protective atmosphere and reactive atmosphere, or ultrasonic operating parameters. It is understood that laser power, scanning pitch, scanning speed, layer thickness, powder supply rate, etc. are part of the LDED process parameters, and LDED forming is performed by adjusting the LDED process parameters. Adjusting the flow rates of the protective atmosphere and reactive atmosphere can be used to control the content of the mixed atmosphere. Adjusting the ultrasonic operating parameters primarily involves adjusting the amplitude, and the ultrasonic frequency can also be changed by replacing the ultrasonic device.

[0077] In some embodiments of the present application, during forming, the activation timing of the atmosphere mixing device 400 and the ultrasonic device is controlled to perform at least one of ultrasonic forming, atmosphere reaction forming, ultrasonic combined atmosphere reaction forming, or LDED forming on the part. It is understood that a program can be set to control the activation and parameters of the ultrasonic wave, the activation and flow rate of the N2 supply, and digitally control the atmosphere reaction and ultrasonic action.

[0078] According to the actual process, it can be roughly divided into the following four situations: parts formed by ultrasonic action, parts formed by atmosphere reaction, parts formed by ultrasonic composite atmosphere reaction, and parts formed by ordinary LDED. At the same time, according to the different ultrasonic and atmosphere supply parameters, it can be divided into more composition situations. Due to the different forming conditions, the part composition, internal microstructure and material properties in the four situations will be different.

[0079] Therefore, parts formed by ultrasonic action, parts formed by atmosphere reaction, parts formed by ultrasonic composite atmosphere reaction, and parts formed by ordinary LDED can be digitally combined according to the program to realize the three-dimensional structural design and customization of parts.

[0080] In some embodiments of the present application, at least one of the reaction atmosphere content, the amount of powdered material, or ultrasonic operating parameters is adjusted in real time during the forming process. It is understood that when the base material components react with the atmosphere, the content of the reactant can be adjusted by adjusting the reaction atmosphere content.

[0081] At the same time, the newly added reaction particles can adjust the content of the reaction substances by adjusting the content of the modified powder and the atmosphere content, thereby adjusting the content of the enhanced components.

[0082] Ultrasonic waves are applied during the atmosphere reaction process, utilizing the cavitation, acoustic streaming, and vibration effects generated by ultrasound in the liquid metal to stir the melt, making the atmosphere reaction more efficient, rapid, and thorough. Ultrasonic waves also help even out the composition of the fluid. Therefore, adding ultrasound and adjusting the ultrasonic operating parameters can help evenly distribute the previously modified, unevenly mixed powders within the molten pool 110 by melting them into a fluid. The ultrasonic vibration process can also reduce the temperature difference and temperature gradient within the molten pool 110, homogenizing and refining the grain structure, disrupting texture orientation, eliminating microscopic defects, reducing residual stress, and improving anisotropy.

[0083] Referring to Figure 1, the device of the second embodiment of the present application can be a device for LDED in-situ atmosphere reaction based on ultrasonic compounding, and the device of the second embodiment of the present application uses the LDED in-situ atmosphere reaction method based on ultrasonic compounding of the first embodiment of the present application, wherein the device includes a forming substrate 100, an atmosphere mixing device 400, an ultrasonic device, a laser forming device and a powder conveying device 500.

[0084] The atmosphere mixing device 400 includes multiple gas input components 410 and an atmosphere mixer 420, and the atmosphere mixer 420 is connected to at least part of the gas input components 410; the ultrasonic device includes an ultrasonic generator 210, an ultrasonic agitator 220 and an ultrasonic vibration platform 230, and the ultrasonic generator 210 is connected to the ultrasonic agitator 220 and the ultrasonic vibration platform 230 respectively; the laser forming device includes a driving component, a laser 310 and a laser nozzle 320, and the laser nozzle 320 is connected to the laser 310, and the driving component is used to drive the laser nozzle 320 to move according to a predetermined trajectory; the forming substrate 100 is arranged on the ultrasonic vibration platform 230, and the ultrasonic agitator 220, the powder conveying device 500, the laser nozzle 320 and the atmosphere mixing device 400 act on the material of the forming substrate 100.

[0085] Referring to Figure 1, the apparatus of the second embodiment of the present application is designed to chemically react and synthesize the LDED forming material and atmosphere components, allowing certain elements in the forming material to chemically react with certain components in the delivery atmosphere to form strengthening components such as metal ceramics. During the LDED forming process, ultrasound is applied to the molten pool 110, stirring the atmosphere with ultrasound to ensure a more complete interaction between the atmosphere and the molten metal, enhancing the reaction effect, increasing the reaction rate and making it more thorough, thereby generating more strengthening components. Furthermore, the ultrasonic stirring effect ensures a more uniform distribution of the strengthening components, thereby enhancing the strengthening effect. Leveraging the differences in composition, microstructure, and properties between the part material formed by LDED under the "ultrasonic combined atmosphere reaction" and the part material produced by conventional LDED forming, the distribution of the part's material composition, microstructure, and properties in a three-dimensional spatial domain is digitally designed. By controlling the reaction and deposition process, the part's material composition, microstructure, and properties are spatially distributed according to the designed distribution, achieving dual structural and material optimization gains.

[0086] 1 , the specific experimental examples of this application are as follows:

[0087] The specific embodiment mainly introduces the reaction between Ti element and N2, but is not limited to this. Any process that can undergo a not very violent synthesis reaction between powder material and atmosphere under the action of laser can adopt the method of the present invention. It is not suitable if there is deflagration or explosion.

[0088] First Experimental Example: Ti element in TC4 (Ti6Al4V) + N2 reacts under laser action to generate titanium nitride TiN. The metal material and gas included in this example are TC4 (Ti6Al4V) titanium alloy and N2.

[0089] Experimental Procedure: Referring to Figure 1, Ti6Al4V metal powder of a certain particle size was added to the powder storage tank of the powder delivery system. N2 was connected to an additional gas cylinder port. A pre-prepared control program was input into the control system to adjust the LDED process parameters (laser power, scan spacing, scan speed, layer thickness, powder supply rate, etc.), the flow rates of the various gases (to control the gas mixture content), and the ultrasonic operating parameters (primarily amplitude; the ultrasonic device can also be replaced to change the ultrasonic frequency). The device was turned on. At this time, the mixed gas on one side was transmitted to the powder delivery system to transport the metal powder material. The mixed gas on the other side served as a shielding gas at the nozzle of the nozzle to form a protective gas barrier to prevent atmospheric influences during the forming process. The ultrasonic device was turned on, and the ultrasonic vibration device was activated. Finally, the LDED system was turned on, and the laser beam was emitted. It interacted with the metal powder, melting the metal powder to form a molten pool 110. The nozzle moved according to the pre-set program until the part was fully formed. During this interaction between the laser and the metal, the N2 in the powder delivery gas and the shielding gas came into contact with the Ti element of the TC4 (Ti6Al4V) titanium alloy in the molten pool 110, causing a reaction. At the same time, the ultrasonic system is turned on during the LDED forming process, and the ultrasonic stirring effect is used to enhance the flow in the molten pool 110, so that the powder conveying gas and N2 in the protective gas can contact more fully with the Ti element of the TC4 (Ti6Al4V) titanium alloy in the molten pool 110, and the reaction is more complete. In addition, the flow also makes the synthetic product titanium nitride TiN more evenly distributed in the molten pool 110.

[0090] Second Experimental Example: A laser-induced reaction between the Ti element in a GH5188 superalloy and pure titanium (Ti) and nitrogen (N) generates titanium nitride (TiN). This example involves a modified mixed powder of a GH5188 superalloy and pure titanium (Ti) and nitrogen (N). The pure titanium powder can contain 0-4% by weight.

[0091] Experimental Procedure: Referring to Figure 1, GH5188 superalloy powder of a certain particle size and pure titanium Ti powder were mixed in a specific mass ratio, ultrasonically dispersed, and thoroughly mixed by ball milling. The resulting mixed, modified powder was then added to the powder storage tank of the powder delivery system. N2 was connected to an additional gas cylinder port. A pre-prepared control program was input into the control system, and the LDED process parameters (laser power, scan spacing, scan speed, layer thickness, powder supply rate, etc.), the flow rates of each gas (to control the content of the mixed gas), and the ultrasonic operating parameters (primarily amplitude; the ultrasonic device can also be replaced to change the ultrasonic frequency) were adjusted. The device was turned on, and the mixed gas on one side was now transmitted to the powder delivery system to transport the metal powder material. The mixed gas on the other side served as a shielding gas at the nozzle of the nozzle to prevent atmospheric influences during the forming process. The ultrasonic device was turned on, and the ultrasonic vibration device was activated. Finally, the LDED system was turned on, and the laser beam emitted, interacting with the metal powder, melting the metal powder to form a molten pool 110. The nozzle then moved according to the programmed program until the part was fully formed. During the interaction between the laser and the metal, N2 in the powder conveying gas and the shielding gas comes into contact with the Ti element of the GH5188 high temperature alloy + pure titanium Ti mixed modified powder in the molten pool 110 and reacts.

[0092] Due to the limited fluidity of the powder, the mixing of the composite material powder is not completely uniform after mixing, ultrasonic dispersion, and ball milling. The ultrasonic stirring effect of the ultrasonic composite atmosphere reaction can promote the full mixing and flow of the metal melt in the molten pool 110, and can further homogenize the material components within the local range of the molten pool 110.

[0093] According to our existing experimental results of atmosphere reaction, the present invention has the following effects compared with the prior art: TiN is found inside the synthetic sample, which significantly enhances the tensile strength, microhardness and other mechanical properties of the matrix material and refines the microstructure.

[0094] Furthermore, the present invention introduces ultrasound mainly to optimize the reaction effect of the LDED forming atmosphere, and mainly introduces ultrasound into the molten metal pool 110. The main methods include: transmitting ultrasound to the substrate through ultrasonic vibration forming substrate 100 and then to the molten metal pool 110; at the same time, using an ultrasonic agitator to directly transmit ultrasound to the molten metal pool 110 through refractory metal.

[0095] The specific steps for the effect of ultrasound on LDED forming are as follows: Before starting LDED forming, the ultrasonic vibration composite device (ultrasonic vibration platform 230 and ultrasonic stirring device, both or only one can be turned on) is turned on. After LDED forming begins, ultrasound is transmitted into the molten pool 110 to exert an effect therein, and the nozzle moves according to the set program until the part is fully formed.

[0096] According to our existing experimental results of ultrasonic composite LDED forming, ultrasonic composite LDED forming of 316L and IN718 has a significant effect on the tensile properties of both, with the benefits of grain refinement and disrupted texture orientation, making the phase distribution more uniform.

[0097] It is understandable that the feasibility and visible enhancement gains of the present invention can be reasonably inferred based on the above two specific embodiments.

[0098] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0099] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. An in-situ atmosphere reaction method of LDED based on ultrasonic compounding, characterized in that: The following steps are involved: Design of chemical reaction synthesis of LDED forming materials and atmosphere components; Complete the design of the three-dimensional structure of the part based on the difference between the forming material and the material after reaction forming, and determine the area for ultrasonic composite atmosphere reaction; A forming substrate, an atmosphere mixing device, a powder conveying device, an ultrasonic device and a laser forming device are configured to perform forming processing; adding powder material into the powder delivery device; The output of the protective atmosphere and the reaction atmosphere is controlled so that the atmosphere mixing device is suitable for outputting a mixed atmosphere with a specific component content; the powder conveying device is controlled to output a specific amount of powder material onto the forming substrate; The laser nozzle of the laser forming device outputs laser light to melt the powder material at the focus to form a molten pool, and the ultrasonic device acts on the molten pool to make the melt in the molten pool contact with the mixed atmosphere to generate an atmosphere synthesis reaction; The laser nozzle is controlled to move along a predetermined trajectory until the part is completely formed.

2. The LDED in-situ atmosphere reaction method based on ultrasonic compounding according to claim 1 is characterized in that: The design of LDED forming materials and atmosphere components includes the design of component types and component contents.

3. The LDED in-situ atmosphere reaction method based on ultrasonic compounding according to claim 2 is characterized in that: The reaction atmosphere is selected according to the composition of the powder material. The powder material is an original alloy powder suitable for atmosphere reaction, or the powder material is a mixed modified powder containing atmosphere reaction elements.

4. The LDED in-situ atmosphere reaction method based on ultrasonic compounding according to claim 3 is characterized in that: The powder material is a mixed modified powder containing atmosphere reaction elements. The preparation method of the mixed modified powder includes: adding the original powder to the modified powder in a certain mass ratio, first performing ultrasonic dispersion, and then performing ball milling to obtain a fully mixed mixed modified powder.

5. The LDED in-situ atmosphere reaction method based on ultrasonic compounding according to claim 3 is characterized in that: The protective atmosphere is Ar; And / or the powder material is an original alloy powder suitable for atmosphere reaction, the original alloy powder is a titanium alloy powder, and the reaction atmosphere is N2; or the original alloy powder is an aluminum alloy powder, and the reaction atmosphere is O2; And / or the powder material is a mixed modified powder containing atmosphere reaction elements, the mixed modified powder includes original powder and modified powder mixed in a certain mass ratio, the original powder is GH5188 high temperature alloy, and the modified powder is pure titanium Ti powder.

6. The LDED in-situ atmosphere reaction method based on ultrasonic compounding according to claim 1, characterized in that: Two atmosphere mixing devices are provided, one of which is connected to the powder conveying device to convey the powder material to the forming substrate through the mixed atmosphere, and the other atmosphere mixing device cooperates with the laser forming device to form a protective gas barrier at the laser nozzle.

7. The LDED in-situ atmosphere reaction method based on ultrasonic compounding according to claim 1 is characterized in that: The process parameters are adjusted before the forming process, and the process parameters include laser power, scanning spacing, scanning speed, layer thickness, powder supply speed, flow rate of protective atmosphere and reaction atmosphere or at least one of ultrasonic working parameters.

8. The LDED in-situ atmosphere reaction method based on ultrasonic compounding according to claim 7 is characterized in that: During the forming process, the opening timing of the atmosphere mixing device and the ultrasonic device is controlled to perform at least one of ultrasonic effect forming, atmosphere reaction forming, ultrasonic composite atmosphere reaction forming or LDED forming on the parts; During the forming process, at least one of the content of the reaction atmosphere, the amount of the powder material or the ultrasonic working parameters is adjusted in real time.

9. An LDED in-situ atmosphere reaction device based on ultrasonic compounding, characterized in that: include: The LDED in-situ atmosphere reaction method based on ultrasonic compounding as described in any one of claims 1 to 8 is used.

10. The LDED in-situ atmosphere reaction equipment based on ultrasonic compounding according to claim 9, characterized in that: include: An atmosphere mixing device, comprising a plurality of gas input components and an atmosphere mixer, wherein the atmosphere mixer is connected to at least part of the gas input components; An ultrasonic device, comprising an ultrasonic generator, an ultrasonic stirrer and an ultrasonic vibration platform, wherein the ultrasonic generator is connected to the ultrasonic stirrer and the ultrasonic vibration platform respectively; A laser forming device, comprising a driving component, a laser and a laser nozzle, wherein the laser nozzle is connected to the laser, and the driving component is used to drive the laser nozzle to move along a predetermined trajectory; Powder conveying device; The forming substrate is arranged on the ultrasonic vibration platform, and the ultrasonic agitator, the powder conveying device, the laser nozzle and the atmosphere mixing device act on the material of the forming substrate.

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