A method, device, equipment and medium for determining the protective gas outlet structure of a 3D powder bed

Abstract

The present invention discloses a method, device, equipment and medium for determining the protective gas outlet structure of a 3D powder bed. The method comprises: establishing an outlet structure simulation model according to the structural parameters of the protective gas outlet structure; inputting the inlet air volume parameters into the simulation model to output the critical simulation speed of the 3D powder bed powder blowing; determining the critical theoretical speed of the 3D powder bed powder blowing; judging whether the deviation between the critical simulation speed and the critical theoretical speed is less than the preset deviation, and whether the critical simulation speed is greater than the minimum splash speed; if so, determining the protective gas outlet structure according to the structural parameters of the protective gas outlet structure; if not, adjusting the structural parameters of the protective gas outlet structure, and returning to the loop execution according to the adjusted structural parameters of the outlet structure until the deviation between the critical simulation speed and the critical theoretical speed is less than the preset deviation, and the critical simulation speed is greater than the minimum splash speed; determining the protective gas outlet structure according to the adjusted structural parameters of the protective gas outlet structure.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of 3D printing technology, and in particular to a method, device, equipment and medium for determining a protective gas outlet structure of a 3D powder bed. Background Art

[0002] Additive Manufacturing (AM) is an advanced manufacturing technology that manufactures parts by stacking materials layer by layer, also known as 3D printing. Compared with traditional subtractive manufacturing methods such as milling or casting, additive manufacturing has the following advantages: 1. Increased design freedom: Additive manufacturing can achieve more complex geometric shapes without considering the limitations of traditional manufacturing processes; 2. Resource conservation: Additive manufacturing can reduce material waste because only the actual required materials need to be used. 3. Rapid manufacturing: Additive manufacturing is usually faster than traditional manufacturing methods and is particularly suitable for small batch production or personalized customization. 4. Prototype manufacturing: Additive manufacturing can quickly produce product prototypes and accelerate the product development cycle.

[0003] In additive manufacturing, powder bed technology is a commonly used method, in which materials are deposited layer by layer in the form of powder, and then melted and solidified by laser beam or electron beam in the environment of protective gas (such as inert gas argon) to form parts. However, powder bed electron beam additive manufacturing technology faces a problem in the forming process, namely "powder blowing", that is, the powder will deviate from its original position under the action of laser beam or electron beam. The surface of the powder is an electrically insulating oxide layer, and the powders are deposited through point contact. After the electron beam is irradiated on the surface of the metal powder, the charge accumulates on the oxide layer on the surface of the powder and waits for redistribution. If the accumulated charge is not discharged in time, the Coulomb repulsion between the powders will be too large, causing "powder blowing"; the powder bed being blown away will cause various adverse effects such as reduced part quality, dimensional deviation, structural instability, printing failure, and difficulty in subsequent processing: since the flow rate of the protective gas (such as inert gas argon) will affect the amount of accumulated charge, it will affect the "powder blowing" phenomenon; therefore, in order to avoid the powder blowing phenomenon, determining the appropriate flow rate of the protective gas plays a key role. Summary of the invention

[0004] The present invention provides a method, device, equipment and medium for determining the protective gas outlet structure of a 3D powder bed, so as to ensure that powder is not blown away during the additive manufacturing process, thereby improving the quality and efficiency of part manufacturing.

[0005] To achieve the above objectives, in a first aspect, an embodiment of the present invention provides a method for determining a protective gas outlet structure of a 3D powder bed, the method comprising:

[0006] Establish an air outlet structure simulation model according to the structural parameters of the protective gas air outlet structure;

[0007] Inputting the inlet air volume parameter into the simulation model to output the critical simulation speed of 3D powder bed powder blowing;

[0008] Determine the critical theoretical speed of 3D powder bed blowing;

[0009] Determine whether the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, and whether the critical simulation speed of the 3D powder bed powder blowing is greater than a minimum splashing speed;

[0010] If not, adjust the structural parameters of the protective gas outlet structure, and return to the loop to execute according to the adjusted structural parameters of the outlet structure until the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than the preset deviation, and the critical simulation speed of the 3D powder bed powder blowing is greater than the minimum splashing speed;

[0011] If so, the protective gas outlet structure is determined according to the structural parameters of the protective gas outlet structure.

[0012] Optionally, determine the critical theoretical velocity of 3D powder bed blowing, including:

[0013] Determine the critical speed of 3D powder bed boundary movement;

[0014] Determine the first expression for the logarithm of the turbulent velocity;

[0015] The critical theoretical speed of 3D powder bed powder blowing is determined according to the critical speed of 3D powder bed boundary movement and the first expression of the logarithm of turbulent velocity.

[0016] Optionally, determining a critical speed of movement of a boundary of a 3D powder bed includes: obtaining a diameter parameter of splashing particles on the powder bed and a density parameter of splashing particles on the powder bed;

[0017] Get the density parameters of the shielding gas;

[0018] The critical speed of the boundary movement of the 3D powder bed is determined according to the diameter parameter of the flying particles on the powder bed, the density parameter of the flying particles on the powder bed and the density parameter of the shielding gas.

[0019] Optionally, the first expression of the logarithm of the turbulent velocity is specifically:

[0020] ;

[0021] in, is the critical speed of movement of the 3D powder bed boundary; is the critical theoretical speed of powder blowing of the 3D powder bed; is a height parameter of the 3D powder bed boundary from the air outlet structure; is the dynamic viscosity parameter of the protective gas flow; is the van der Waals constant; is the logarithmic integration constant of the near-wall layer of fully turbulent flow.

[0022] Optionally, the critical speed of the 3D powder bed boundary movement is determined according to the diameter parameter of the flying particles on the powder bed, the density parameter of the flying particles on the powder bed and the density parameter of the shielding gas, specifically:

[0023] ;

[0024] in, is the critical speed of movement of the 3D powder bed boundary; is the diameter parameter of the splashing particles on the powder bed; is the density parameter of the protective gas; is the ratio of the density parameter of the splashing particles on the powder bed to the density parameter of the shielding gas; is the acceleration due to gravity; is a constant; is a constant.

[0025] Optionally, the minimum splash velocity is determined by the material properties of the 3D powder bed.

[0026] In a second aspect, an embodiment of the present invention further provides a device for determining a protective gas outlet structure of a 3D powder bed, the device comprising:

[0027] A model building module is used to build a simulation model of the air outlet structure according to the structural parameters of the protective gas air outlet structure;

[0028] A simulation speed output module, used for inputting the inlet air volume parameter into the simulation model to output the critical simulation speed of 3D powder bed powder blowing;

[0029] Theoretical speed determination module, used to determine the critical theoretical speed of 3D powder bed powder blowing;

[0030] A judgment module, used to judge whether the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, and whether the critical simulation speed of the 3D powder bed powder blowing is greater than a minimum splashing speed;

[0031] an adjusting module, for adjusting the structural parameters of the protective gas outlet structure when the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, or the critical simulation speed of the 3D powder bed powder blowing is less than a minimum splashing speed, and returning to loop execution according to the adjusted structural parameters of the outlet structure until the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, and the critical simulation speed of the 3D powder bed powder blowing is greater than a minimum splashing speed;

[0032] A shielding gas outlet structure determination module is used to determine the shielding gas outlet structure according to the structural parameters of the adjusted shielding gas outlet structure; or to directly determine the shielding gas outlet structure according to the structural parameters of the shielding gas outlet structure when the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, and the critical simulation speed of the 3D powder bed powder blowing is greater than the minimum splashing speed.

[0033] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for determining the protective gas outlet structure of the 3D powder bed described in the first aspect.

[0034] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the method for determining the protective gas outlet structure of a 3D powder bed described in the first aspect.

[0035] In the embodiment of the present invention, a simulation model of an air outlet structure is established according to the structural parameters of the protective gas air outlet structure; the inlet air volume parameters are input into the simulation model to output the critical simulation speed of 3D powder bed powder blowing; the critical theoretical speed of 3D powder bed powder blowing is determined; it is determined whether the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than a preset deviation, and whether the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed; if so, the actual protective gas outlet structure is determined according to the structural parameters of the protective gas outlet structure; if not, the structural parameters of the protective gas outlet structure are adjusted, and the cycle is returned to execute according to the adjusted air outlet structure. The structural parameters are adjusted until the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than the preset deviation, and the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed; the shielding gas outlet structure is determined according to the structural parameters of the adjusted shielding gas outlet structure; the actual shielding gas outlet structure determined in this way outputs a 3D powder bed powder blowing critical actual speed close to the 3D powder bed powder blowing critical theoretical speed under the same inlet air volume parameter conditions, which can prevent the powder bed from being blown away; at the same time, the critical actual speed of 3D powder bed powder blowing is greater than the minimum splashing speed, which also ensures that the splash generated during laser melting of powder is taken away. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of a method for determining a protective gas outlet structure of a 3D powder bed provided by an embodiment of the present invention;

[0037] Figure 2 It is a flow chart of another method for determining the protective gas outlet structure of a 3D powder bed provided by an embodiment of the present invention;

[0038] Figure 3 It is a structural schematic diagram of a device for determining a protective gas outlet structure of a 3D powder bed provided by an embodiment of the present invention;

[0039] Figure 4 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0041] Figure 1is a flow chart of a method for determining a protective gas outlet structure of a 3D powder bed provided by an embodiment of the present invention. This embodiment can be applied to determining the actual protective gas outlet structure of a 3D powder bed. The method can be executed by a protective gas outlet structure determination device for a 3D powder bed, such as Figure 1 As shown, the method specifically comprises the following steps:

[0042] S110, establishing an air outlet structure simulation model according to the structural parameters of the protective gas air outlet structure.

[0043] The shielding gas outlet structure is a structure for discharging shielding gas (such as inert gas argon) to protect the powder material during the process of melting and solidifying the 3D powder bed by laser beam or electron beam to form parts; the shielding gas outlet structure can be a body structure type; the structural parameters of the shielding gas outlet structure include the height parameter and the cross-sectional area parameter of the shielding gas outlet structure;

[0044] An air outlet structure simulation model is established according to the height parameters and cross-sectional area parameters of the protective gas air outlet structure, and the corresponding air outlet structure simulation model may be a body structure simulation model.

[0045] S120, inputting the inlet air volume parameter into the simulation model to output the critical simulation speed of 3D powder bed powder blowing.

[0046] Among them, the inlet air volume parameter is the standard inlet air volume parameter when the shielding gas outlet structure is at a certain height Z; the inlet air volume parameter is input into the simulation model to output the critical simulation speed of 3D powder bed powder blowing; the critical simulation speed of 3D powder bed powder blowing is the simulation speed at which the shielding gas outlet structure discharges shielding gas at a certain height Z without causing the powder to be blown away.

[0047] S130, determining the critical theoretical speed of 3D powder bed powder blowing.

[0048] Among them, the critical theoretical speed of 3D powder bed powder blowing is the theoretical speed at which the protective gas outlet structure discharges the protective gas at a certain height Z without causing the powder to be blown away; the critical theoretical speed of 3D powder bed powder blowing can be determined by the powder flow properties and aerodynamic characteristics.

[0049] S140. Determine whether the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than the preset deviation, and whether the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed; if not, execute S150-160; if yes, directly execute S160.

[0050] Among them, the preset deviation t is the allowable deviation value of the critical simulation speed of 3D powder bed powder blowing close to the critical theoretical speed of 3D powder bed powder blowing; exemplarily, the preset deviation t is 10-20%; that is, |critical simulation speed of 3D powder bed powder blowing-critical theoretical speed of 3D powder bed powder blowing| / critical theoretical speed of 3D powder bed powder blowing=t; the minimum splashing speed is the minimum speed at which the splashes generated during laser melting of powder are carried away; the minimum splashing speed is determined by the properties of the 3D powder bed material.

[0051] When the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than the preset deviation, the critical simulation speed of 3D powder bed powder blowing can ensure that the powder will not be blown away when the shielding gas is discharged at a certain height Z; at the same time, the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed, so that the critical simulation speed of 3D powder bed powder blowing also ensures that the splash generated during laser melting of powder is taken away.

[0052] S150, adjusting the structural parameters of the protective gas outlet structure, and returning to the loop to execute according to the adjusted structural parameters of the outlet structure until the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than the preset deviation, and the critical simulation speed of the 3D powder bed powder blowing is greater than the minimum splashing speed.

[0053] Among them, when the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is greater than the preset deviation, or the critical simulation speed of 3D powder bed powder blowing is less than the minimum splashing speed, the structural parameters of the protective gas outlet structure can be adjusted. Specifically, the cross-sectional parameters of the outlet structure can be adjusted, and the loop execution is returned to establish an updated outlet structure simulation model according to the adjusted structural parameters of the outlet structure; the inlet air volume parameters are input into the updated simulation model to output the updated critical simulation speed of 3D powder bed powder blowing; until the deviation between the updated critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than the preset deviation, and the updated critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed, so that the updated critical simulation speed of 3D powder bed powder blowing can ensure that the powder will not be blown away when the protective gas is discharged at a certain height Z, and at the same time ensure that the splash generated by laser melting the powder is taken away.

[0054] S160. Determine a protective gas outlet structure according to structural parameters of the protective gas outlet structure.

[0055] Among them, the structural parameters of the updated shielding gas outlet structure corresponding to the updated critical simulation speed of 3D powder bed powder blowing can determine the actual shielding gas outlet structure. Under the same inlet air volume parameter conditions, the actual shielding gas outlet structure outputs the 3D powder bed powder blowing critical actual speed close to the 3D powder bed powder blowing critical theoretical speed, which can prevent the powder bed from being blown away by the shielding gas and ensure that the splashes generated during laser melting of the powder are taken away, solving the problem of powder blowing in the prior art.

[0056] When the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than the preset deviation, and the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed, the actual shielding gas outlet structure is determined directly according to the structural parameters of the shielding gas outlet structure. Under the same inlet air volume parameter conditions, the actual shielding gas outlet structure determined in this way outputs a critical actual speed of 3D powder bed powder blowing close to the critical theoretical speed of 3D powder bed powder blowing, which can prevent the powder bed from being blown away by the shielding gas and ensure that the splashing generated by laser melting the powder is taken away.

[0057] Optionally, based on the above embodiment, step S130 is further refined. Figure 2 FIG. 1 is a flow chart of another method for determining the protective gas outlet structure of a 3D powder bed provided by an embodiment of the present invention. Figure 2 As shown, the method comprises the following steps:

[0058] S210, establishing an air outlet structure simulation model according to the structural parameters of the protective gas air outlet structure.

[0059] S220, input the inlet air volume parameter into the simulation model to output the critical simulation speed of 3D powder bed powder blowing.

[0060] S230, determining the critical speed of movement of the 3D powder bed boundary.

[0061] Among them, determining the critical speed of the 3D powder bed boundary movement includes: obtaining the diameter parameters of the flying particles on the powder bed and the density parameters of the flying particles on the powder bed; obtaining the density parameters of the shielding gas; and determining the critical speed of the 3D powder bed boundary movement according to the diameter parameters of the flying particles on the powder bed, the density parameters of the flying particles on the powder bed and the density parameters of the shielding gas.

[0062] Specifically, the critical speed of the 3D powder bed boundary movement is determined according to the diameter parameter of the splashing particles on the powder bed, the density parameter of the splashing particles on the powder bed, and the density parameter of the shielding gas:

[0063] ; (1)

[0064] in, Critical speed for 3D powder bed boundary movement; is the diameter parameter of the splashing particles on the powder bed; is the density parameter of the shielding gas; It is the ratio of the density parameter of the splashing particles on the powder bed to the density parameter of the shielding gas; is the acceleration due to gravity; is a constant; is a constant; it should also be noted that in the above formula (1), it can be assumed that the splashing particles on the powder bed are dry and relatively regular circles; the particles are loosely distributed on the powder bed; and the splashing particles on the powder bed are distributed on a dry surface.

[0065] S240, determining a first expression of the logarithm of the turbulent velocity;

[0066] Among them, constructing the first expression of the logarithm of turbulent velocity includes: obtaining the dynamic viscosity parameters of the protective gas flow; obtaining the height parameters of the 3D powder bed boundary from the air outlet structure; and constructing the first expression of the logarithm of turbulent velocity according to the dynamic viscosity parameters, height parameters, the critical speed of 3D powder bed boundary movement and the critical theoretical speed of 3D powder bed powder blowing.

[0067] Specifically, the first expression of the logarithm of turbulent velocity is:

[0068] ; (2)

[0069] in, Critical speed for 3D powder bed boundary movement; The critical theoretical speed of 3D powder bed powder blowing; It is the height parameter of the 3D powder bed boundary from the air outlet structure; is the dynamic viscosity parameter of the shielding gas flow; is the van der Waals constant; is the logarithmic integral constant of the near-wall layer of complete turbulence; it should be noted that for the area 1 to 3 mm above the powder bed where the boundary layer transitions to the turbulent region, the first expression of the logarithm of the turbulent velocity is satisfied in this region; Within 1~3mm.

[0070] S250, determining the critical theoretical speed of powder blowing of the 3D powder bed according to the critical speed of the 3D powder bed boundary movement and the first expression of the logarithm of the turbulent velocity.

[0071] Among them, the critical theoretical speed of 3D powder bed powder blowing The critical velocity for the movement of the 3D powder bed boundary is obtained by substituting the first expression of the logarithm of the turbulent velocity.

[0072] S260. Determine whether the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than the preset deviation, and whether the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed; if not, execute S270-S280; if yes, directly execute S280.

[0073] S270, adjusting the structural parameters of the protective gas outlet structure, and returning to the loop to execute according to the adjusted structural parameters of the outlet structure until the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than the preset deviation, and the critical simulation speed of the 3D powder bed powder blowing is greater than the minimum splashing speed.

[0074] S280. Determine a protective gas outlet structure according to structural parameters of the protective gas outlet structure.

[0075] In this embodiment, a process for determining the critical theoretical speed of 3D powder bed powder blowing is specifically given, so that when judging whether the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than the preset deviation, and whether the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed; an accurate judgment result can be given, and the structural parameters of the shielding gas outlet structure can be precisely adjusted, so that the shielding gas outlet structure can be accurately determined according to the structural parameters of the shielding gas outlet structure.

[0076] The embodiment of the present invention also provides a device for determining the protective gas outlet structure of a 3D powder bed.

[0077] A method for determining the protective gas outlet structure of a 3D powder bed provided by any embodiment of the present invention can be executed, and has corresponding functional modules and beneficial effects of the execution method; Figure 3 is a schematic diagram of a structure of a device for determining a protective gas outlet structure of a 3D powder bed provided by an embodiment of the present invention, such as Figure 3 As shown, the device comprises:

[0078] A model building module 10 is used to build a simulation model of the air outlet structure according to the structural parameters of the protective gas air outlet structure;

[0079] A simulation speed output module 20 is used to input the inlet air volume parameter into the simulation model to output the critical simulation speed of 3D powder bed powder blowing;

[0080] Theoretical speed determination module 30 is used to determine the critical theoretical speed of 3D powder bed powder blowing;

[0081] A judgment module 40 is used to judge whether the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than a preset deviation, and whether the critical simulation speed of 3D powder bed powder blowing is greater than a minimum splashing speed;

[0082] The regulating module 50 is used for adjusting the structural parameters of the protective gas outlet structure when the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than a preset deviation, or the critical simulation speed of 3D powder bed powder blowing is less than a minimum splashing speed, and returning to the loop to execute according to the adjusted structural parameters of the outlet structure until the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than a preset deviation, and the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed;

[0083] The shielding gas outlet structure determination module 60 is used to determine the shielding gas outlet structure according to the structural parameters of the adjusted shielding gas outlet structure; or to directly determine the shielding gas outlet structure according to the structural parameters of the shielding gas outlet structure when the deviation between the critical simulation speed of 3D powder bed powder blowing and the critical theoretical speed of 3D powder bed powder blowing is less than a preset deviation, and the critical simulation speed of 3D powder bed powder blowing is greater than the minimum splashing speed.

[0084] An embodiment of the present invention further provides an electronic device, Figure 4 1 is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0085] like Figure 4 As shown, the electronic device 100 includes at least one processor 11, and a memory connected to the at least one processor 11 in communication, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by the at least one processor 11, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the random access memory (RAM) 13, various programs and data required for the operation of the electronic device 100 can also be stored. The processor 11, the read-only memory (ROM) 12, and the random access memory (RAM) 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0086] A number of components in the electronic device 100 are connected to an input / output (I / O) interface 15, including an input unit 16, such as a keyboard, a mouse, etc., an output unit 17, such as various types of displays, speakers, etc., a storage unit 18, such as a disk, an optical disk, etc., and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 100 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0087] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a method for determining a protective gas outlet structure of a 3D powder bed.

[0088] In some embodiments, a method for determining a protective gas outlet structure of a 3D powder bed may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 100 via a read-only memory (ROM) 12 and / or a communication unit 19. When the computer program is loaded into a random access memory (RAM) 13 and executed by the processor 11, one or more steps of the method for determining a protective gas outlet structure of a 3D powder bed described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to execute a method for determining a protective gas outlet structure of a 3D powder bed in any other appropriate manner (e.g., by means of firmware).

[0089] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0090] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0091] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, device, or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0092] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0093] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0094] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0095] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0096] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0097] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for determining a protective gas outlet structure of a 3D powder bed, characterized in that: include: Establish an air outlet structure simulation model according to the structural parameters of the protective gas air outlet structure; Inputting the inlet air volume parameter into the simulation model to output the critical simulation speed of 3D powder bed powder blowing; Determine the critical theoretical speed of 3D powder bed powder blowing; wherein, the critical theoretical speed of 3D powder bed powder blowing is the critical theoretical speed at which the protective gas outlet structure discharges the protective gas at a certain height Z without causing the powder to be blown away; the critical theoretical speed of 3D powder bed powder blowing is determined by the powder flow properties and the aerodynamic characteristics; Determine whether the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, and whether the critical simulation speed of the 3D powder bed powder blowing is greater than a minimum splashing speed; If yes, determine the protective gas outlet structure according to the structural parameters of the protective gas outlet structure; If not, adjust the structural parameters of the protective gas outlet structure, and return to the loop to execute according to the adjusted structural parameters of the outlet structure until the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than the preset deviation, and the critical simulation speed of the 3D powder bed powder blowing is greater than the minimum splashing speed.

2. The method for determining the protective gas outlet structure of a 3D powder bed according to claim 1, characterized in that: Determine the critical theoretical velocity of 3D powder bed blowing, including: Determine the critical speed of 3D powder bed boundary movement; Determine the first expression for the logarithm of the turbulent velocity; The critical theoretical speed of powder blowing of the 3D powder bed is determined according to the critical speed of the 3D powder bed boundary movement and the first expression of the logarithm of the turbulent velocity.

3. The method for determining the protective gas outlet structure of a 3D powder bed according to claim 2, characterized in that: Determine the critical speed of 3D powder bed boundary movement, including: obtaining the diameter parameter of the splashing particles on the powder bed and the density parameter of the splashing particles on the powder bed; Get the density parameters of the shielding gas; The critical speed of the boundary movement of the 3D powder bed is determined according to the diameter parameter of the flying particles on the powder bed, the density parameter of the flying particles on the powder bed and the density parameter of the shielding gas.

4. The method for determining the protective gas outlet structure of a 3D powder bed according to claim 3, characterized in that: Determine the first expression for the logarithm of the turbulent velocity, including: Obtain the dynamic viscosity parameters of the shielding gas flow; Obtaining a height parameter of the 3D powder bed boundary from the air outlet structure; A first expression for the logarithm of turbulent velocity is constructed according to the dynamic viscosity parameter, the height parameter, the critical velocity of the 3D powder bed boundary movement and the critical theoretical velocity of the 3D powder bed powder blowing.

5. The method for determining the protective gas outlet structure of a 3D powder bed according to claim 4, characterized in that: The first expression of the logarithm of the turbulent velocity is specifically: ； in, is the critical speed of movement of the 3D powder bed boundary; is the critical theoretical speed of powder blowing of the 3D powder bed; is a height parameter of the 3D powder bed boundary from the air outlet structure; is the dynamic viscosity parameter of the protective gas flow; is the van der Waals constant; is the logarithmic integration constant of the near-wall layer of fully turbulent flow.

6. The method for determining the protective gas outlet structure of a 3D powder bed according to claim 4, characterized in that: The critical speed of the 3D powder bed boundary movement is determined according to the diameter parameter of the flying particles on the powder bed, the density parameter of the flying particles on the powder bed and the density parameter of the shielding gas, specifically: ； in, is the critical speed of movement of the 3D powder bed boundary; is the diameter parameter of the splashing particles on the powder bed; is the density parameter of the shielding gas; is the ratio of the density parameter of the splashing particles on the powder bed to the density parameter of the shielding gas; is the acceleration due to gravity; is a constant; is a constant.

7. The method for determining the protective gas outlet structure of a 3D powder bed according to claim 1, characterized in that: The minimum splash velocity is determined by the 3D powder bed material properties.

8. A device for determining the protective gas outlet structure of a 3D powder bed, characterized in that: include: A model building module is used to build a simulation model of the air outlet structure according to the structural parameters of the protective gas air outlet structure; A simulation speed output module, used for inputting the inlet air volume parameter into the simulation model to output the critical simulation speed of 3D powder bed powder blowing; Theoretical speed determination module is used to determine the critical theoretical speed of 3D powder bed powder blowing; wherein, the critical theoretical speed of 3D powder bed powder blowing is the critical theoretical speed at which the protective gas outlet structure discharges the protective gas at a certain height Z without causing the powder to be blown away; the critical theoretical speed of 3D powder bed powder blowing is determined by the powder flow properties and the airflow dynamics characteristics; A judgment module, used to judge whether the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, and whether the critical simulation speed of the 3D powder bed powder blowing is greater than a minimum splashing speed; an adjusting module, for adjusting the structural parameters of the protective gas outlet structure when the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, or the critical simulation speed of the 3D powder bed powder blowing is less than a minimum splashing speed, and returning to loop execution according to the adjusted structural parameters of the outlet structure until the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, and the critical simulation speed of the 3D powder bed powder blowing is greater than a minimum splashing speed; A shielding gas outlet structure determination module is used to determine the shielding gas outlet structure according to the structural parameters of the adjusted shielding gas outlet structure; or to directly determine the shielding gas outlet structure according to the structural parameters of the shielding gas outlet structure when the deviation between the critical simulation speed of the 3D powder bed powder blowing and the critical theoretical speed of the 3D powder bed powder blowing is less than a preset deviation, and the critical simulation speed of the 3D powder bed powder blowing is greater than the minimum splashing speed.

9. An electronic device, characterized in that: The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for determining the protective gas outlet structure of the 3D powder bed described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the method for determining the protective gas outlet structure of a 3D powder bed according to any one of claims 1 to 7 when executed.

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