A method and apparatus for in-situ LDED atmosphere reaction based on ultrasonic composite

Abstract

This application discloses an in-situ atmosphere reaction method and equipment for LDED based on ultrasonic composite deposition. The method includes the following steps: designing the reaction zone of the forming material and atmosphere components; preparing powder material; configuring a forming substrate, atmosphere mixing device, powder conveying device, ultrasonic device, and laser forming device for forming; controlling the output of the protective atmosphere and reaction atmosphere, and the amount of powder conveyed by the powder conveying device; the laser forming device melts the material to form a molten pool, ultrasonic waves act on the molten pool, and the laser moves along a trajectory to form the part. By designing the reaction between the powder and the atmosphere, reinforcing components are synthesized to enhance the material. Ultrasonic waves strengthen the reaction between the atmosphere and the melt, resulting in a uniform distribution of the reinforcing components. The atmosphere supply and ultrasonic action are controlled to adjust the atmosphere synthesis reaction and component content. Combined with the deposition trajectory, the material composition, microstructure, and properties of the part are spatially distributed according to the design, achieving dual optimization gains in structure and material.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing technology, and in particular to an in-situ atmosphere reaction method and equipment for LDED based on ultrasonic composite. Background Technology

[0002] Laser Directed Energy Deposition (LDED) is a relatively efficient laser additive manufacturing technology that can rapidly deposit and form metal parts. However, its disadvantages include poor dimensional accuracy and surface quality. Furthermore, due to the extremely high forming speed of LDED, the overall forming temperature of the part is high, resulting in greater internal stress and a higher likelihood of cracking and other defects. Moreover, due to coarse grains and numerous porosity defects, the forming performance of the parts is inferior to that of laser selective melting and other laser additive manufacturing technologies. Therefore, it is necessary to improve the forming material properties through techniques and methods. Summary of the Invention

[0003] The purpose of this application is to at least solve one of the technical problems existing in the prior art. To this end, this application proposes an in-situ atmosphere reaction method for LDED based on ultrasonic composite, which can achieve the shaping of the material composition, microstructure and properties of the part according to the design in space by controlling the reaction, component content and deposition trajectory movement, thereby achieving dual optimization gains in structure and materials.

[0004] This application also proposes an apparatus for using the above-described ultrasonic-based LDED in-situ atmosphere reaction method.

[0005] The LDED in-situ atmosphere reaction method based on ultrasonic composite according to the first aspect of this application includes the following steps:

[0006] Design of chemical reaction synthesis for LDED forming materials and atmosphere composition;

[0007] The design of the three-dimensional structure of the part is completed based on the difference between the forming material and the material after reaction forming, and the area for ultrasonic composite atmosphere reaction is determined.

[0008] The powder material is added to the powder conveying device;

[0009] The device is equipped with a forming substrate, an atmosphere mixing device, a powder conveying device, an ultrasonic device, and a laser forming device for forming processing.

[0010] Specifically, the output amounts of the protective atmosphere and the reactive atmosphere are controlled to make the atmosphere mixing device 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;

[0011] The laser nozzle of the laser forming device outputs laser light, which melts the powder material at the focal point to form a molten pool. The molten pool is then subjected to an ultrasonic device, which causes the melt in the molten pool to come into contact with the mixed atmosphere and undergo an atmospheric synthesis reaction.

[0012] The laser nozzle is controlled to move along a predetermined trajectory until the part is fully formed.

[0013] The ultrasonic composite LDED in-situ atmosphere reaction method according to the first aspect of this application has at least the following beneficial effects: Chemical reaction synthesis design is performed on the LDED forming material and atmosphere components, allowing certain elements in the forming material to chemically react with certain components in the conveying atmosphere to synthesize strengthening components. Simultaneously, ultrasound acts on the molten pool, using ultrasonic waves to stir the atmosphere reaction, making the interaction between the atmosphere and the molten metal more complete, enhancing the reaction effect, increasing the reaction rate and degree, and generating more strengthening components. Furthermore, the ultrasonic stirring action makes the distribution of strengthening components more uniform, enhancing its strengthening effect. Compared with existing technologies, the "ultrasonic composite atmosphere reaction" can achieve the spatially designed distribution of the part material composition, microstructure, and properties by controlling the reaction, component content, and deposition trajectory movement, achieving dual optimization gains in both structure and materials.

[0014] According to the ultrasonic composite-based in-situ atmosphere reaction method for LDED as described in the first aspect of this application, the design of LDED forming material and atmosphere composition includes the design of component types and component content.

[0015] According to the first aspect of the present application, the LDED in-situ atmosphere reaction method based on ultrasonic composite is wherein the reaction atmosphere is selected according to the composition of the powder material, wherein the powder material is a raw alloy powder suitable for atmosphere reaction, or the powder material is a mixed modified powder containing atmosphere reaction elements.

[0016] According to the first aspect of the present application, the LDED in-situ atmosphere reaction method based on ultrasonic composite 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 ball milling to obtain a fully mixed modified powder.

[0017] According to the ultrasonic composite-based LDED in-situ atmosphere reaction method according to the first aspect of this application, the protective atmosphere is Ar;

[0018] And / or the powder material is a raw alloy powder suitable for atmospheric reaction, wherein the raw alloy powder is a titanium alloy powder and the reaction atmosphere is N2; or the raw alloy powder is an aluminum alloy powder and the reaction atmosphere is O2;

[0019] And / or the powder material is a mixed modified powder containing atmospheric reactive elements, wherein the mixed modified powder comprises a raw powder and a modified powder mixed in a certain mass ratio, the raw powder being GH5188 high-temperature alloy and the modified powder being pure titanium Ti powder.

[0020] According to the first aspect of the embodiment of the present application, the LDED in-situ atmosphere reaction method based on ultrasonic composite is provided in two atmosphere mixing devices. One of the atmosphere mixing devices is connected to the powder conveying device and conveys the powder material to the forming substrate through the mixed atmosphere. The other atmosphere mixing device cooperates with the laser forming device to form a protective gas barrier at the laser nozzle.

[0021] According to the ultrasonic composite LDED in-situ atmosphere reaction method described in the first aspect of this application, the process parameters are adjusted before forming and processing. The process parameters include at least one of the following: laser power, scanning spacing, scanning speed, layer thickness, powder supply speed, flow rate of protective atmosphere and reaction atmosphere, or ultrasonic working parameters.

[0022] According to the first aspect of the present application, the ultrasonic composite LDED in-situ atmosphere reaction method is used to control the timing of the opening of the atmosphere mixing device and the ultrasonic device during the forming process, so as to perform at least one of ultrasonic action forming, atmosphere reaction forming, ultrasonic composite atmosphere reaction forming or LDED forming on the part.

[0023] During the forming process, at least one of the following is adjusted in real time: the content of the reaction atmosphere, the content of the powder material, or the ultrasonic working parameters.

[0024] The ultrasonic-based LDED in-situ atmosphere reaction apparatus according to a second aspect of this application includes: using the ultrasonic-based LDED in-situ atmosphere reaction method described in the first aspect of this application.

[0025] It is easy to understand that the LDED in-situ atmosphere reaction device based on ultrasonic composite in the second aspect embodiment of this application has the same technical effects as the LDED in-situ atmosphere reaction method based on ultrasonic composite in the first aspect embodiment, and therefore will not be described again.

[0026] The LDED in-situ atmosphere reaction device based on ultrasonic composite according to the second aspect of this application includes:

[0027] An atmosphere mixing device includes a plurality of gas input components and an atmosphere mixer, the atmosphere mixer being connected to at least a portion of the gas input components;

[0028] An ultrasonic device includes 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.

[0029] A laser forming apparatus includes 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;

[0030] Powder conveying device;

[0031] A shaped substrate is disposed 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 shaped substrate.

[0032] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0033] The present application will be further described below with reference to the accompanying drawings and embodiments;

[0034] Figure 1 This is a system schematic diagram of an embodiment of this application.

[0035] Figure label:

[0036] 100. Molten substrate; 110. Molten pool;

[0037] 210. Ultrasonic generator; 220. Ultrasonic stirrer; 230. Ultrasonic vibration platform;

[0038] 310. Laser; 320. Laser nozzle;

[0039] 400. Atmosphere mixing device; 410. Gas input component; 420. Atmosphere mixer;

[0040] 500. Powder conveying device. Detailed Implementation

[0041] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0042] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0043] In the description of this application, "several" means one or more, "more than" means at least two, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0044] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly. Those skilled in the art can reasonably determine the specific meaning of the above terms in this application after considering the specific content of the technical solution.

[0045] Understandably, laser-directed energy deposition (LDED) is a major technical approach in laser additive manufacturing. This technology uses a laser beam as the main energy source, forms the motion trajectory of the laser nozzle 320 based on 3D model slice data, sets deposition parameters, and focuses the metal powder and laser at the same focal point to form a molten pool 110. With the motion trajectory of the metal nozzle and the interaction between the laser and the metal powder, the metal powder is eventually melted and solidified into a solid part.

[0046] Reference Figure 1 The first aspect of this application relates to an ultrasonic composite LDED in-situ atmosphere reaction method, which relates to ultrasonic composite laser directional energy deposition technology in the field of composite laser additive manufacturing technology, and particularly to an ultrasonic composite LDED in-situ atmosphere reaction synthesis enhancement method. The ultrasonic composite LDED in-situ atmosphere reaction method includes the following steps:

[0047] Design of chemical reaction synthesis for LDED forming materials and atmosphere composition;

[0048] The design of the three-dimensional structure of the part is completed based on the difference between the forming material and the material after reaction forming, and the area for ultrasonic composite atmosphere reaction is determined.

[0049] The device is equipped with a forming substrate 100, an atmosphere mixing device 400, a powder conveying device 500, an ultrasonic device, and a laser forming device for forming processing.

[0050] The powder material is added to the powder conveying device 500;

[0051] Among them, the output of protective atmosphere and reactive 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 onto the forming substrate 100;

[0052] The laser nozzle 320 of the laser forming device outputs laser light, which melts the powder material at the focal point to form a molten pool 110. The ultrasonic device acts on the molten pool 110, so that the melt in the molten pool 110 comes into contact with the mixed atmosphere and undergoes an atmospheric synthesis reaction.

[0053] Control the laser nozzle 320 to move along a predetermined trajectory until the part is fully formed.

[0054] Understandably, in the laser-directed energy deposition (LDED) system of related technologies, during the step-by-step accumulation forming process following the laser nozzle's 320-degree trajectory, metal powder is typically transported to the laser focal point by argon gas. Simultaneously, argon gas acts as a protective atmosphere, filling the forming cavity or forming a gas barrier near the forming nozzle to prevent oxidizing gases in the atmosphere from reacting with the molten metal and causing oxidation. However, this can negatively impact material properties. Therefore, in some embodiments of this application, the composition of the powder material formed by LDED and the composition of the gas transporting the powder are designed so that they undergo a chemical reaction under laser irradiation to generate substances that enhance the properties of the raw materials, thereby strengthening the material's performance.

[0055] It should be noted that ultrasound can generate cavitation, acoustic flow, and vibration effects in liquid metal and stir the melt. Therefore, ultrasound can be used to enhance the chemical reaction between the metal material and the atmosphere in the molten pool 110 during LDED (Laser-Directed Energy Deposition) process, thereby using ultrasound to uniformly synthesize the distribution of material composition. Simultaneously, ultrasound also has the effects and benefits in LDED forming, such as refining grains, homogenizing material composition, homogenizing the temperature field, reducing stress and temperature gradients, and disrupting preferred grain orientation.

[0056] In some embodiments, the method of configuring the forming substrate 100, atmosphere mixing device 400, powder conveying device 500, ultrasonic device, and laser forming device includes: setting the deposition control program, mainly setting the switching timing of the reaction gas conveying and the ultrasonic device, that is, turning on the ultrasonic device and gas conveying switch when forming the "ultrasonic composite atmosphere reaction" area of ​​LDED. At the same time, parameters such as the gas conveying flow rate and ultrasonic amplitude can be set or controlled in real time. After completing the program configuration, the program is imported into the controller. After testing and running the program without errors, the forming substrate 100 is installed, the device is turned on, and the atmosphere mixing device 400, powder conveying device 500, ultrasonic device (acting on the LEDE molten pool 110), and laser forming device (including laser nozzle 320, laser 310, controller, drive component for driving the spindle movement of laser nozzle 320, water cooling device, etc.) are configured, and then forming processing is performed.

[0057] In some embodiments, the laser emitted from the laser nozzle 320 melts the metal powder at the focal point, forming a molten pool 110. The molten metal in the molten pool 110 comes into contact with the mixed atmosphere and undergoes an atmospheric 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 flow enhance the convection within 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 flow effect makes the molten metal tend to be uniform, further homogenizing the distribution of the synthesized strengthening substance, making its subsequent strengthening effect more uniform and improving the consistency of material properties.

[0058] Simultaneously, the drive unit moves the laser nozzle 320 along a predetermined trajectory, melting and solidifying it step by step into the designed part. Finally, when processing reaches the non-atmosphere reaction zone designed for the part, the output of the mixed atmosphere is stopped, and the ultrasonic device can be programmed to turn on and off as needed.

[0059] Reference Figure 1 The first aspect of this application describes an in-situ atmosphere reaction method for LDED based on ultrasonic composite technology. This method involves chemically reacting and synthesizing the LDED forming material and atmosphere components. Certain elements in the forming material react with certain components in the transport atmosphere to synthesize strengthening components. Simultaneously, ultrasound is applied to the molten pool 110, stirring the atmosphere reaction and enhancing the interaction between the atmosphere and the molten metal. This strengthens the reaction, increases the reaction rate, and makes it more thorough, resulting in more strengthening components. Furthermore, the ultrasonic stirring action ensures a more uniform distribution of the strengthening components, further enhancing the strengthening effect. Compared to existing technologies, this "ultrasonic composite atmosphere reaction" can achieve spatially designed distribution of the part's material composition, microstructure, and properties by controlling the reaction, component content, and deposition trajectory movement, thus achieving dual optimization gains in both structure and materials.

[0060] It is understood that this invention combines ultrasonic composite stirring, material-atmosphere interaction reaction, and three-dimensional structural design and customization of material composition to optimize the microstructure, composition, and material structure properties of LDED forming.

[0061] In some embodiments of this application, the design of the LDED forming material and atmosphere composition includes the design of the types and amounts of components. It is understood that the LDED forming material and atmosphere composition are designed for chemical reaction synthesis, so that certain elements in the forming material can chemically react with certain components in the transport atmosphere to synthesize reinforcing components such as metal ceramics.

[0062] In some embodiments, based on the material properties and microstructure composition characteristics after the "ultrasonic composite atmosphere reaction," the material composition and microstructure of the laser-directed energy deposition (LDED) shaped parts are spatially designed, and the LDED process is set. Only in certain designed spatial forming areas is the "ultrasonic composite atmosphere reaction" used to customize the composition and crystal structure of the part's spatial region. Under such spatial structure-material design and forming, the part's performance and spatial stress distribution characteristics can be optimized through a dual composite optimization of structure and materials.

[0063] In some embodiments of this application, the reaction atmosphere is selected based on the composition of the powder material. The powder material is either a raw alloy powder suitable for atmospheric reactions or a mixed modified powder containing atmospheric reaction elements. In some embodiments, when designing the chemical reaction synthesis of the LDED forming material and the atmosphere composition, the composition of the transport gas needs to be designed based on the composition of the base material for LDED forming. For example, if a titanium alloy contains Ti, it can react with nitrogen to generate titanium nitride, a reinforcing component. If an aluminum alloy contains Al, it can react with oxygen to generate alumina. If the base material composition does not contain any components that can react with the gas, or in order not to damage the original material composition, certain powder particles that can react with the atmosphere, such as pure titanium or pure zirconium powder particles, can be added to the base forming material composition according to the actual reaction requirements. The reaction atmosphere can then be oxygen, nitrogen, etc.

[0064] In some embodiments of this application, the method for preparing 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 modified powder, which can then be added to the powder conveying device 500.

[0065] In some embodiments of this application, the protective atmosphere is Ar, but other inert gases may also be used as the protective atmosphere.

[0066] In some embodiments of this application, the original alloy powder is titanium alloy powder, and the reaction atmosphere is N2. In other embodiments of this application, the original alloy powder is aluminum alloy powder, and the reaction atmosphere is O2.

[0067] Understandably, during the forming process, the protective atmosphere Ar gas and the forming reaction atmosphere (nitrogen, oxygen, etc.) are output from the storage device to the mixing chamber for mixing. A flow valve is installed between the storage device and the mixing chamber to control the flow rate of the two gases and thus control the composition content of the mixed atmosphere.

[0068] In some embodiments of this application, the mixed modified powder includes a mixture of original powder and modified powder in a certain mass ratio, wherein the original powder is GH5188 high-temperature alloy and the modified powder is pure titanium (Ti) powder.

[0069] In some embodiments, the modified powder includes the original powder: GH5188 high-temperature alloy powder and the modified powder: pure titanium Ti powder. Before forming and processing, the GH5188 high-temperature alloy powder and pure titanium Ti powder are mixed in a certain mass ratio, first ultrasonically dispersed, and then ball-milled to fully mix. The resulting mixed modified powder is added to the powder conveying device 500.

[0070] Understandably, the Ti element in the GH5188 high-temperature alloy + pure titanium Ti reacts with N2 under laser irradiation to generate titanium nitride TiN, which can enhance the tensile strength, microhardness and other mechanical properties of the matrix material, and refine the microstructure.

[0071] It is understandable that the example of GH5188 high-temperature alloy is just one specific embodiment and is not specifically intended for any particular application. The specific applications of this patent are very broad.

[0072] In some embodiments of this application, two atmosphere mixing devices 400 are provided. One atmosphere mixing device 400 is connected to the powder conveying device 500 and conveys powder material to the forming substrate 100 through a mixed atmosphere. The other atmosphere mixing device 400 cooperates with the laser forming device to form a protective gas barrier at the laser nozzle 320. It can be understood that two atmosphere mixing devices 400 are provided, one connected to the powder conveying device 500 and the other located near the laser forming device. 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 adjustment of composition and the modified powder with added reactive components. After the mixed atmosphere is introduced, the powder is conveyed to the focusing point of the laser by gas conveying.

[0073] In some embodiments, the modified powder mainly refers to metal powder added to the reactants according to a certain mass percentage and then mixed. Preferably, the mixture is made by ultrasonic dispersion followed by ball milling to ensure thorough and uniform mixing.

[0074] In other embodiments, the modified powder may also be prepared from other metal powders with reinforcing effects by a similar mixing method.

[0075] In some embodiments of this application, process parameters are adjusted before forming. These parameters include at least one of the following: laser power, scanning spacing, scanning speed, layer thickness, powder supply speed, flow rate of the protective atmosphere and the reaction atmosphere, or ultrasonic operating parameters. It is understood that laser power, scanning spacing, scanning speed, layer thickness, powder supply speed, etc., are part of the LDED process parameters, and LDED forming is performed by adjusting these parameters. Adjusting the flow rates of the protective atmosphere and the reaction atmosphere can be used to control the content of the mixed atmosphere. Adjusting the ultrasonic operating parameters mainly involves the amplitude, and the ultrasonic frequency can also be changed by replacing the ultrasonic device.

[0076] In some embodiments of this application, during forming processes, the timing of the activation of the atmosphere mixing device 400 and the ultrasonic device is controlled to perform at least one of ultrasonic forming, atmosphere reaction forming, ultrasonic composite 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 waves, whether the N2 nitrogen supply is on, and the supply flow rate to digitally control the atmosphere reaction and ultrasonic action.

[0077] Based on the actual process, it can be roughly divided into the following four situations: ultrasonically formed parts, atmospheric reaction formed parts, ultrasonically combined atmospheric reaction formed parts, and ordinary LDED formed parts. At the same time, depending on the different ultrasonic and atmospheric supply parameters, it can be further divided into more composition situations. Due to the different forming conditions, the composition, internal microstructure and material properties of the parts in the four situations will be different.

[0078] Therefore, parts formed by ultrasonic action, parts formed by atmospheric reaction, parts formed by ultrasonic composite atmospheric 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.

[0079] In some embodiments of this application, during the forming process, at least one of the following is adjusted in real time: the content of the reaction atmosphere, the amount of powder material, or the ultrasonic operating parameters. It is understood that when the base material components react with the atmosphere, the content of the reactant can be adjusted by regulating the content of the reaction atmosphere.

[0080] Meanwhile, the newly added reactive particles can adjust the content of reactive substances by adjusting the content of the modified powder and the atmosphere, thereby adjusting the content of the reinforcing components.

[0081] Ultrasonic waves are applied during the atmospheric reaction process. The cavitation, acoustic flow, and vibration effects generated by ultrasound in liquid metal are used to stir the melt, making the atmospheric reaction more efficient, rapid, and thorough. Furthermore, ultrasound has the effect of homogenizing the composition of the fluid. Therefore, by adding ultrasound and adjusting its operating parameters, the previously unevenly mixed modified powder can be melted into a fluid within the molten pool 110 and further homogenized. During ultrasonic vibration, the temperature difference and temperature gradient within the molten pool 110 can also be reduced, homogenizing and refining the grain structure, disrupting texture orientation, eliminating microscopic defects, reducing residual stress, and improving anisotropy.

[0082] Reference Figure 1 The apparatus of the second aspect of this application may be an apparatus for in-situ LDED reaction based on ultrasonic composite, and the apparatus of the second aspect of this application uses the in-situ LDED reaction method based on ultrasonic composite of the first aspect of this application, wherein the apparatus includes a forming substrate 100, an atmosphere mixing device 400, an ultrasonic device, a laser forming device, and a powder conveying device 500.

[0083] The atmosphere mixing device 400 includes multiple gas input components 410 and an atmosphere mixer 420, with the atmosphere mixer 420 connected to at least a portion of the gas input components 410; the ultrasonic device includes an ultrasonic generator 210, an ultrasonic stirrer 220, and an ultrasonic vibration platform 230, with the ultrasonic generator 210 connected to both the ultrasonic stirrer 220 and the ultrasonic vibration platform 230; the laser forming device includes a driving component, a laser 310, and a laser nozzle 320, with the laser nozzle 320 connected to the laser 310, and the driving component driving the laser nozzle 320 to move along a predetermined trajectory; the forming substrate 100 is disposed on the ultrasonic vibration platform 230, and the ultrasonic stirrer 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.

[0084] Reference Figure 1The apparatus of the second aspect of this application is designed to chemically react and synthesize LDED forming materials and atmosphere components, enabling certain elements in the forming material to chemically react with certain components in the conveying atmosphere to synthesize strengthening components such as metal ceramics. During the LDED forming process, ultrasound is applied to the molten pool 110, and the atmosphere reaction is stirred using ultrasound, making the interaction between the atmosphere and the molten metal more complete, enhancing the reaction effect, increasing the reaction rate and degree, and generating more strengthening components. Furthermore, the ultrasonic stirring effect makes the distribution of strengthening components more uniform, enhancing its strengthening effect. Utilizing the differences in composition, microstructure, and properties between the LDED-formed part material and the part material produced by traditional LDED forming under the action of "ultrasonic composite atmosphere reaction," the distribution of the part's material composition, microstructure, and properties in a three-dimensional spatial region is digitally designed. By controlling the reaction and deposition process, the part's material composition, microstructure, and properties are formed according to the designed spatial distribution, achieving dual optimization gains in both structure and material.

[0085] Reference Figure 1 The specific experimental embodiments of this application are as follows:

[0086] The specific embodiments mainly introduce the reaction between Ti element and N2 nitrogen gas, but are not limited to this. Any synthesis reaction in which powder material and atmosphere can undergo a not very violent reaction under laser action can be carried out using the method of this invention. However, it is not suitable if deflagration or explosion occurs.

[0087] First experimental example: Ti in TC4 (Ti6Al4V) reacts with N2 under laser irradiation to form titanium nitride (TiN). The metal material and gas involved in this example are TC4 (Ti6Al4V) titanium alloy and N2 nitrogen gas, respectively.

[0088] Experimental procedure: (Refer to) Figure 1Ti6Al4V metal powder of a certain particle size is added to the powder storage tank of the powder conveying system, and N2 is connected to an additional gas cylinder interface. The pre-prepared control program is input into the control system, adjusting the LDED process parameters (laser power, scanning spacing, scanning speed, layer thickness, powder supply speed, etc.), the flow rate of each gas (controlling the content of the mixed gas), and the ultrasonic operating parameters (mainly amplitude; the ultrasonic device can also be replaced to change the ultrasonic frequency). The device is turned on. At this time, the mixed gas on one side is transmitted to the powder conveying system to transport the metal powder material, while the mixed gas on the other side acts as a protective gas, forming a protective gas barrier at the nozzle to prevent atmospheric influence during the forming process. The ultrasonic device is turned on, and the ultrasonic vibration device is activated. Finally, the LDED system is turned on, the laser emits light, and it interacts with the metal powder, melting the metal powder to form a molten pool 110. The nozzle moves according to the set program until the part is completely formed. During the interaction between the laser and the metal, the N2 nitrogen in the powder conveying gas and protective gas comes into contact with the Ti element of the TC4 (Ti6Al4V) titanium alloy in the molten pool 110, and a reaction occurs. Meanwhile, during the LDED forming process, the ultrasonic system is turned on, and the stirring effect of the ultrasonic waves enhances the flow in the molten pool 110, so that the nitrogen gas in the powder conveying gas and protective gas has more sufficient contact 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 synthesis product titanium nitride TiN more uniformly distributed in the molten pool 110.

[0089] Second experimental example: GH5188 high-temperature alloy + Ti element from pure titanium (Ti) reacts with N2 under laser irradiation to generate titanium nitride (TiN). The metal materials and gases included in this example are a mixed modified powder of GH5188 high-temperature alloy and pure titanium (Ti), and nitrogen gas (N2). The mass content of the pure titanium (Ti) powder can be 0-4%.

[0090] Experimental procedure: (Refer to) Figure 1GH5188 high-temperature alloy powder of a certain particle size is mixed with pure titanium (Ti) powder in a certain mass ratio, ultrasonically dispersed, and ball-milled to obtain a mixed modified powder. This powder is then added to the powder storage tank of the powder conveying system, and N2 is connected to an additional gas cylinder interface. The pre-prepared control program is input into the control system, and the LDED process parameters (laser power, scanning spacing, scanning speed, layer thickness, powder supply speed, etc.), the flow rate of each gas (controlling the content of the mixed gas), and the ultrasonic working parameters (mainly amplitude; the ultrasonic device can also be replaced to change the ultrasonic frequency) are adjusted. The device is then turned on. At this time, the mixed gas on one side is transmitted to the powder conveying system to transport the metal powder material, and the mixed gas on the other side acts as a protective gas to form a protective gas barrier at the nozzle of the nozzle to prevent atmospheric influence during the forming process. The ultrasonic device is turned on, and the ultrasonic vibration device is turned on. Finally, the LDED system is turned on, the laser emits light, and it interacts with the metal powder to melt the metal powder and form a molten pool 110. The nozzle moves according to the set program until the part is completely formed. During the interaction between the laser and the metal, the nitrogen gas (N2) in the powder conveying gas and protective gas comes into contact with the Ti element in the GH5188 high-temperature alloy + pure titanium Ti mixed modified powder in the molten pool 110, and a reaction occurs.

[0091] Due to the limited flowability of powder, even after mixing, ultrasonic dispersion, and ball milling, the composite powder is not completely uniform. The ultrasonic stirring effect of the ultrasonic composite atmosphere reaction can promote the full mixing and flow of the molten metal in the molten pool 110, and can further homogenize the material composition in a local area of ​​the molten pool 110.

[0092] Based on our experimental results of existing atmosphere reactions, the advantages of this invention compared to existing technologies are: TiN was found inside the synthesized sample, which significantly enhanced the tensile strength, microhardness and other mechanical properties of the matrix material, and refined the microstructure.

[0093] Furthermore, the introduction of ultrasound in this invention is mainly to optimize the reaction effect of the LDED forming atmosphere. The main method is to introduce ultrasound into the molten metal pool 110. The main methods include: transmitting ultrasound to the substrate and then to the molten metal pool 110 by vibrating the forming substrate with ultrasound; at the same time, using an ultrasonic stirrer to directly transmit ultrasound to the molten metal pool 110 through the refractory metal.

[0094] The specific steps of the effect of ultrasound on LDED forming are as follows: Before starting LDED forming, turn on the ultrasonic vibration composite device (ultrasonic vibration platform 230 and ultrasonic stirring device, either one or only one can be turned on). After LDED forming begins, the ultrasound is transmitted to the molten pool 110 and acts on the molten pool 110. The nozzle moves according to the set program until the part is completely formed.

[0095] Based on our existing experimental results of ultrasonic composite LDED forming, ultrasonic composite LDED forming of 316L and IN718 has a significant effect on improving their tensile properties. The benefits of grain refinement and disrupting the texture orientation result in a more uniform phase distribution.

[0096] It is understandable that the feasibility and visible enhancement gains of the present invention can be reasonably inferred from the two specific embodiments described above.

[0097] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0098] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A method for in-situ LDED atmosphere reaction based on ultrasonic composite, characterized in that, Includes the following steps: The design of LDED forming materials and atmosphere composition involves the selection and content of components. The design of the three-dimensional structure of the part is completed based on the difference between the forming material and the material after reaction forming, and the area for ultrasonic composite atmosphere reaction is determined. The device is equipped with a forming substrate, an atmosphere mixing device, a powder conveying device, an ultrasonic device, and a laser forming device for forming processing. The powder material is added to the powder conveying device; The output of the protective atmosphere and the reactive atmosphere is controlled to make the atmosphere mixing device suitable for outputting a mixed atmosphere with a specific component content; the reactive atmosphere is selected according to the composition of the powder material, which is either a raw alloy powder suitable for atmospheric reaction or a mixed modified powder containing atmospheric reactive elements; the preparation method of the mixed modified powder includes: adding the raw powder to the modified powder in a certain mass ratio, first performing ultrasonic dispersion, and then ball milling to obtain a fully mixed modified powder; 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, which melts the powder material at the focal point to form a molten pool. The molten pool is then subjected to an ultrasonic device, which causes the melt in the molten pool to come into contact with the mixed atmosphere and undergo an atmospheric synthesis reaction. The laser nozzle is controlled to move along a predetermined trajectory until the part is fully formed.

2. The LDED in-situ atmosphere reaction method based on ultrasonic composite according to claim 1, characterized in that: The protective atmosphere is Ar; Alternatively, the powder material may be a raw alloy powder suitable for atmospheric reaction, wherein the raw alloy powder is titanium alloy powder, and the reaction atmosphere is N2; Alternatively, the powder material may be a raw alloy powder suitable for atmospheric reaction, wherein the raw alloy powder is aluminum alloy powder, and the reaction atmosphere is O2; Alternatively, the powder material may be a mixed modified powder containing atmospheric reactive elements, wherein the mixed modified powder comprises a raw powder and a modified powder mixed in a certain mass ratio, the raw powder being GH5188 high-temperature alloy and the modified powder being pure titanium (Ti) powder.

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

4. The LDED in-situ atmosphere reaction method based on ultrasonic composite according to claim 1, characterized in that: Before forming, adjust the process parameters, including at least one of the following: laser power, scanning spacing, scanning speed, layer thickness, powder supply speed, flow rate of protective atmosphere and reaction atmosphere, or ultrasonic working parameters.

5. The LDED in-situ atmosphere reaction method based on ultrasonic composite according to claim 4, characterized in that: During the forming process, the timing of the activation of the atmosphere mixing device and the ultrasonic device is controlled to perform at least one of ultrasonic action forming, atmosphere reaction forming, ultrasonic composite atmosphere reaction forming, or LDED forming on the part. During the forming process, at least one of the following is adjusted in real time: the content of the reaction atmosphere, the amount of the powder material, or the ultrasonic working parameters.

6. An LDED in-situ atmosphere reaction device based on ultrasonic composite, characterized in that, include: The LDED in-situ atmosphere reaction method based on ultrasonic composite as described in any one of claims 1 to 5 further includes: An atmosphere mixing device includes a plurality of gas input components and an atmosphere mixer, the atmosphere mixer being connected to at least a portion of the gas input components; An ultrasonic device includes 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 apparatus includes 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; A shaped substrate is disposed 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 shaped substrate.

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