A method of additive manufacturing a stable formation

Abstract

The application discloses a kind of methods for the stable forming of additive manufacturing, the grid framework model is constructed, and the printing part model is established, and based on the grid framework model and printing part model, additive manufacturing is carried out to realize stable forming.The method uses a grid framework model covering preheating forming area, and the powder bed is solidified by electron beam outer contour point scanning mode, solves the problems of powder bed cracking, powder bed peeling and other problems in the processing process of traditional process, enhances the stability of powder bed, and helps to realize the stable forming of high-temperature alloy electron beam additive manufacturing.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature alloys and additive manufacturing technology, and relates to a method for achieving stable forming in additive manufacturing. Background Technology

[0002] High-temperature alloys are materials used in aerospace power systems, energy generation systems, and other high-temperature and harsh environments. They play a crucial role in the research and development of aero-engines, often referred to as the "crown jewel" of industry. The manufacturing of turbine blades, the most important hot-end component, is considered the "jewel in the crown" of industry due to its stringent process requirements and demanding service conditions. Currently, the manufacturing of high-temperature alloy turbine blades mainly relies on directional solidification casting and subsequent heat treatment. This process is cumbersome, time-consuming, and yields low success rates. Furthermore, directional solidification high-temperature alloys obtained through casting suffer from severe dendritic element segregation, and achieving microstructure homogenization through heat treatment is difficult. The mechanical properties of directional solidification columnar materials obtained through traditional manufacturing processes are also difficult to further improve.

[0003] Electron beam powder-layout additive manufacturing technology boasts a short forming cycle, high production efficiency, and a high degree of freedom in process design, enabling near-net-shape forming of complex components. This provides more possibilities for manufacturing high-temperature alloy materials with superior performance. The manufacturing process primarily relies on "layer-by-layer melting and deposition." A three-dimensional component is sliced ​​to obtain layered two-dimensional planes. Electron beam selective melting is then performed on the laid metal powder layers. Finally, the deposition of these two-dimensional molten planes yields a three-dimensional part with the desired shape and size.

[0004] In electron beam additive manufacturing, a stable powder bed is crucial for the successful formation of 3D components. Problems such as powder bed deformation, cracking, and peeling during processing can adversely affect the forming process. These adverse effects are mainly manifested in two aspects: First, the uneven distribution of powder in the preheating forming area will directly affect the quality of electron beam selective melting, ultimately leading to a decrease in the material properties of the printed part model; Second, powder bed cracking and peeling will cause localized accumulation of metal powder in the preheating forming area during subsequent powder laying. These areas are prone to powder blowing during subsequent electron beam processing, leading to equipment arcing failures and processing failures.

[0005] Therefore, there is an urgent need for a suitable method to solve problems such as powder bed cracking and powder bed peeling that occur during the processing, so as to ensure the stability of the powder bed and achieve stable forming of high-temperature alloy electron beam additive manufacturing. Summary of the Invention

[0006] The purpose of this invention is to stably achieve electron beam powder-layout selective melting additive manufacturing of high-temperature alloys. A method for stable additive manufacturing is disclosed, which constructs a mesh framework model and establishes a printed part model. Additive manufacturing is performed based on the mesh framework model and the printed part model to achieve stable forming. This method utilizes a mesh framework model covering the preheating forming area and solidifies the powder bed through electron beam outer contour point scanning. This solves problems such as powder bed cracking and delamination that occur during traditional processes, enhances the stability of the powder bed, and helps achieve stable forming of high-temperature alloys in electron beam additive manufacturing, thus completing this invention.

[0007] Specifically, the purpose of this invention is to provide a method for stable additive manufacturing, the method comprising:

[0008] Step 1, construct the mesh framework model;

[0009] Step 2: Create a model of the printed part;

[0010] Step 3: Perform additive manufacturing based on the mesh frame model and the printed part model to achieve stable forming.

[0011] Optionally, step 1 includes the following steps:

[0012] Step 1-1: Create the inner mesh frame and the outer mesh frame respectively;

[0013] Steps 1-2: Construct a mesh frame model based on the internal mesh frame and the external mesh frame.

[0014] Optionally,

[0015] In step 1-1, creating the internal mesh framework includes the following steps:

[0016] Step 1-1-1: Create the internal filling primitive;

[0017] Step 1-1-2: Array copy the internal filling primitives to obtain the internal mesh frame.

[0018] Optionally,

[0019] In step 1-1-1, the internal filling primitive is obtained by creating a first cuboid model with length, width, and height of N4, N5, and N6, respectively, and a second cuboid model with length, width, and height of N5, N4, and N6, respectively. The center coordinates of the first and second cuboid models are consistent and they are arranged perpendicularly to each other.

[0020] Optionally,

[0021] In step 1-1-2, there are no gaps between the internal filling elements.

[0022] Optionally,

[0023] In step 1-1, creating the outer mesh frame includes the following steps:

[0024] Step 1-1-1': Create the peripheral reinforcement primitive;

[0025] Step 1-1-2': Around the inner mesh frame, the outer reinforcement primitives are arrayed and copied to obtain the outer mesh frame.

[0026] Optionally,

[0027] Step 1-1-1' includes the following steps:

[0028] Establish three cuboid models, where the length, width, and height of cuboid model M1 are N7, N8, and N9, respectively; the length, width, and height of cuboid model M2 are N8, N7, and N9, respectively; and the length, width, and height of cuboid model M3 are N7, N7, and N9, respectively.

[0029] The three cuboid models are merged to obtain the outer reinforcement element.

[0030] Optionally, N7 > N8.

[0031] Optionally,

[0032] In steps 1-2, the inner mesh frame is placed inside the outer mesh frame to obtain the mesh frame model.

[0033] Optionally,

[0034] Step 3 includes the following steps:

[0035] Step 3-1: Import the mesh frame model and the printed part model into the slicing software to generate the printing file;

[0036] Step 3-2: Import the print file into the printing operation software and set the processing parameters for the mesh frame model and the print part model;

[0037] Step 3-3: Perform additive manufacturing based on the processing parameters to achieve stable forming.

[0038] The beneficial effects of this invention include:

[0039] (1) The present invention provides a method for stable forming of additive manufacturing. The grid frame model makes the powder bed stable and does not crack during the forming process, which fundamentally solves the problems of powder blowing failure, arcing failure and processing failure caused by powder bed cracking, and realizes the successful printing of high temperature alloy materials.

[0040] (2) The present invention provides a method for stable forming of additive manufacturing, which uses a network frame model and a printed part model to process the network frame on the substrate by means of electron beam “outer contour point scanning” and the printed part by means of “internal scanning filling”, and then directly lays powder on the substrate for additive manufacturing, providing a new idea for additive repair of high temperature alloy blade materials.

[0041] (3) The method for achieving stable forming of alloy electron beam additive manufacturing provided by the present invention will not greatly reduce the printing efficiency due to the introduction of the mesh frame model. Attached Figure Description

[0042] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0043] In the attached diagram:

[0044] Figure 1 This diagram illustrates a preferred embodiment of the present invention for constructing an internally filled primitive structure.

[0045] Figure 1 (a) shows a schematic diagram of a first cuboid model structure for constructing an internally filled primitive structure according to a preferred embodiment of the present invention;

[0046] Figure 1 (b) shows a schematic diagram of a second cuboid model structure for constructing an internally filled primitive structure according to a preferred embodiment of the present invention;

[0047] Figure 1 (c) A schematic diagram of the internal filling element structure of a preferred embodiment of the present invention is shown;

[0048] Figure 2 This diagram illustrates an internal grid frame structure according to a preferred embodiment of the present invention.

[0049] Figure 3 This diagram illustrates a preferred embodiment of the present invention for constructing a peripheral mesh frame structure.

[0050] Figure 3 (a) shows a structural schematic diagram of a cuboid model M1 for constructing an outer mesh frame structure according to a preferred embodiment of the present invention;

[0051] Figure 3 (b) shows a structural schematic diagram of a cuboid model M2 for constructing an outer mesh frame structure according to a preferred embodiment of the present invention;

[0052] Figure 3 (c) shows a structural schematic diagram of a cuboid model M3 for constructing an outer mesh frame structure according to a preferred embodiment of the present invention;

[0053] Figure 3 (d) shows a schematic diagram of the peripheral mesh frame structure of a preferred embodiment of the present invention;

[0054] Figure 4 This diagram illustrates a preferred embodiment of the mesh frame model structure of the present invention.

[0055] Figure 5 The image shows a printed representation of the mesh frame in Example 1.

[0056] Figure 6 The image shows the effect of the stainless steel substrate and the printed parts in Example 1;

[0057] Figure 7 The image shows the printed effect of the mesh frame in Comparative Example 1;

[0058] Figure 8 The image shows the printed effect of the grid frame in Comparative Example 2. Detailed Implementation

[0059] The following will refer to the appendix. Figures 1 to 8 Specific embodiments of the invention will be described in more detail below. While specific embodiments of the invention are shown in the accompanying drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0060] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0061] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0062] According to the present invention, an additive manufacturing method for stable forming includes:

[0063] Step 1, construct the mesh framework model;

[0064] Step 2: Create a model of the printed part;

[0065] Step 3: Perform additive manufacturing based on the mesh frame model and the printed part model to achieve stable forming.

[0066] The above-mentioned additive manufacturing stable forming method is described in detail below.

[0067] Step 1, constructing the mesh framework model. According to a preferred embodiment, Step 1 includes the following steps:

[0068] Step 1-1: Create the inner mesh frame and the outer mesh frame respectively;

[0069] Steps 1-2: Construct a mesh frame model based on the internal mesh frame and the external mesh frame.

[0070] In step 1-1, creating the internal mesh framework includes the following steps:

[0071] Step 1-1-1: Create the internal filling primitive.

[0072] In a preferred embodiment, such as Figure 1 As shown, a first cuboid model with length, width, and height of N4, N5, and N6 respectively is created in the modeling software (e.g., ...). Figure 1 (a) shows), and a second cuboid model with length, width, and height of N5, N4, and N6 is created (as shown in the image). Figure 1 (b) shows the internal filling primitives, where the center coordinates of the first and second cuboid models are consistent and they are arranged perpendicularly to each other, as shown. Figure 1 As shown in (c).

[0073] Step 1-1-2: Array copy the internal filling primitives to obtain the internal mesh frame.

[0074] In a preferred embodiment, the model obtained by arraying and replicating the internal filling primitives in the XY plane is the internal mesh framework, such as... Figure 2 As shown. There are no gaps between the internal filling elements to ensure that the internal mesh frame is a connected body.

[0075] In step 1-1, creating the outer mesh frame includes the following steps:

[0076] Step 1-1-1': Create the peripheral reinforcement primitive.

[0077] In a preferred embodiment, such as Figure 3 As shown, three cuboid models are established. The length, width, and height of cuboid model M1 are N7, N8, and N9, respectively (as shown in the figure). Figure 3 (a) shows that the length, width, and height of the cuboid model M2 are N8, N7, and N9, respectively (as shown in the figure). Figure 3 (b) As shown, the length, width, and height of the cuboid model M3 are N7, N7, and N9 respectively (as shown in the figure). Figure 3 (c) shows that N7 > N8. The three cuboid models are merged to obtain the outer reinforcement element, as shown. Figure 3 As shown in (d).

[0078] According to the present invention, the "outer" part of the mesh frame model, namely the outer mesh frame, is the part most prone to powder bed breakage leading to powder blowing. Therefore, the basic elements constituting the outer mesh frame, namely the outer reinforcement basic elements, adopt a nested arrangement of three cuboid models. Among them, the cuboid model M3 constitutes the outer contour of the outer reinforcement basic element. In order to further strengthen the powder bed inside the outer reinforcement basic element, the simplest and fastest way is to have the electron beam process the outer perimeter of the outer reinforcement basic element and then scan a "+" shape inside. However, if it is just drawn as a line, that is, N8 is set to 0, the electron beam cannot be recognized and will not be processed by default. Therefore, the cuboid model M2 or cuboid model M1 nested inside the cuboid model M3 is preferably a rectangle with a high aspect ratio, which ensures that the electron beam can smoothly process the outer contour and meets the requirement of the "+" shape.

[0079] Step 1-1-2': Around the inner mesh frame, the outer reinforcement primitives are arrayed and copied to obtain the outer mesh frame.

[0080] In this invention, steps 1-2' can be understood as: Arraying and replicating the peripheral reinforcement elements around the internal mesh frame in the XY plane; the resulting model is the peripheral mesh frame. The outer dimensions of the internal mesh frame are the same as the inner dimensions of the peripheral mesh frame.

[0081] There are no gaps between the peripheral reinforcement units.

[0082] In step 1-1, the outer dimensions of the outer mesh frame are usually the same as those of the preheating forming area; the preheating forming area is determined according to the size of the substrate.

[0083] Furthermore, the length, width, and height dimensions of the outer mesh frame, i.e., the preheating and forming area, are set to N1, N2, and N3, respectively. The length N1 of the outer mesh frame is (8~10) mm smaller than the length of the substrate, and the width N2 of the outer mesh frame is (8~10) mm smaller than the width of the preheating and forming area. For example, the length and width of the substrate are 120 mm and 120 mm, respectively; the length N1 and width N2 of the outer mesh frame are 110 mm and 110 mm, respectively.

[0084] According to the present invention, when the substrate is filled with metal powder during electron beam additive manufacturing, the electron beam cannot directly sweep the metal powder during preheating, otherwise powder blowing will occur. If the preheating forming area and the substrate are the same size, the lower beam of the electron beam may sweep the powder outside the metal substrate due to the error of the substrate placement or the instability of the electron beam deflection, which will lead to powder blowing and be detrimental to the processing. Therefore, a certain margin should be left between the preheating forming area and the substrate, but the margin should not be too large, otherwise the preheating area will become smaller, the substrate preheating will be slower, and the processing efficiency will be reduced. It is more appropriate for the length N1 of the outer grid frame to be (8~10) mm smaller than the length of the substrate, and the width N2 of the outer grid frame to be (8~10) mm smaller than the width of the preheating forming area.

[0085] Furthermore, the value of N3 depends on the height at which the powder bed tends to stabilize. The significance of the mesh frame model is to solve the problem of powder bed instability. In alloy electron beam additive manufacturing experiments, the powder bed thickness usually stabilizes after reaching 2 mm. Therefore, the value of N3 is set to be no less than 2 mm, for example, 2 mm.

[0086] In step 1-1, the values ​​of N1:N4:N5 are typically (90~110):(9~11):1, for example, 110:10:1. For instance, when N1 is 110 mm, N4 can be 10 mm, and N5 can be 1 mm. This is because: a value of 1 mm for N5 is generally sufficient, and the values ​​of N1:N4 are controlled within (90~110):(9~11). Taking an N1:N4 value of 100:10 as an example, this is equivalent to the internal mesh frame being a 10x10 array composed of 100 internal filling elements. If the value of N4 is too small, the number of internal filling elements increases, prolonging the processing time of the mesh frame model and negatively impacting production efficiency. If the value of N4 is too large, the effect of solidifying the powder bed is poor, and the problem of powder bed cracking cannot be solved. The optimal effect is achieved when N1, N4, and N5 are within the aforementioned ranges.

[0087] In step 1-1, the value of N6 is preferably the same as that of N3.

[0088] In step 1-1, the length, width, and height of the internal grid frame in step 1-2 are set to W1, W2, and W3, respectively, and the value of W3 is preferably the same as that of N3.

[0089] In step 1-1, the N1:N7 value is usually (18~22):1, preferably 22:1. For example, when the N1 value is 110mm, the N7 value can be 5mm. A slightly smaller N7 value can increase the density of the peripheral reinforcing units, resulting in more complete powder bed curing and less cracking on the periphery of the powder bed. However, if the value is too small, the processing time of the mesh frame model will be extended, which is detrimental to production efficiency.

[0090] In step 1-1, the preferred value of N7:N4 is 1:(2~3), for example, 1:2.

[0091] In step 1-1, the N7:N8 value is usually (4~6):1, for example 5:1. When the N7 value is 5mm, the N8 value can be 1mm.

[0092] In step 1-1, under normal circumstances, the dimensions of the peripheral reinforcement unit meet the following requirements: (2N7+W1) = N1, (2N7+W2) = N2, N9 = N3.

[0093] Steps 1-2: Based on the internal mesh frame and the external mesh frame, obtain the mesh frame model.

[0094] In steps 1-2, the inner mesh frame is placed within the outer mesh frame to obtain the mesh frame model, as shown below. Figure 4 As shown.

[0095] In this invention, the grid frame serves to strengthen the powder bed in the preheating and forming area, preventing problems such as powder bed cracking and peeling during processing.

[0096] In step 1, the mesh framework model can be established using any technique in the art, such as general modeling software like Solidworks or Materialise Magics.

[0097] Step 2: Create a model of the printed part.

[0098] In step 2, the printed part model can be established using any technique in the art. For example, the required dimensions and center coordinates can be set using general modeling software such as Solidworks or Materialise Magics to establish the printed part model.

[0099] In this invention, electron beam additive manufacturing technology can meet the manufacturing and forming needs of alloy components of various shapes. It achieves the manufacturing of three-dimensional components by selectively melting powder layers on a two-dimensional plane with an electron beam and then stacking layers perpendicular to the melting plane. Creating a printed part model is a fundamental step in electron beam additive manufacturing. For example, to obtain a 10x10x10 mm cube alloy part, a 10x10x10 mm printed part model must first be created, and then imported into the additive manufacturing equipment for processing.

[0100] In this invention, a grid frame model is used to solidify the powder bed in the preheating and molding area. The printed part model can be set at any position in the preheating and molding area, or the printed part model can be arranged at any position in the grid frame model. It is preferred to arrange it according to certain rules, such as arranging it at the "top", "bottom", "left", "right" and center positions of the grid frame model.

[0101] Step 3: Perform additive manufacturing based on the mesh frame model and the printed part model to achieve stable forming.

[0102] According to a preferred embodiment, step 3 includes the following steps:

[0103] Step 3-1: Import the mesh frame model and the printed part model into the slicing software to generate the print file.

[0104] In step 3-1, the mesh frame model and the printed part model are imported into the slicing software, and the slicing thickness, melting spacing and rotation angle between slices are set.

[0105] Furthermore, the slice thickness is the thickness of the additive manufacturing process established after completing one printing cycle. Typically, the slice thickness is 0.05~0.1mm, for example, 0.07mm. The set melting gap is the distance between the "lines" formed by the molten powder when the electron beam scans the powder along a straight line during one printing cycle. The melting gap is typically 0.08~0.12mm, for example, 0.10mm. The rotation angle between the slices is the angle difference between the slices during the printing process. The rotation angle is generally 90°.

[0106] Step 3-2: Import the print file into the printing operation software and set the processing parameters for the mesh frame model and the print part model.

[0107] In step 3-2, the mesh frame model is preferably processed using the electron beam "outer contour point scanning" method, with the following parameter settings: electron beam power 200~300W, scanning speed 500~700 mm / s, for example, electron beam power 240W, scanning speed 600 mm / s; the printed part model is processed using the "internal scanning and filling" method, with processing parameters of scanning speed 500~4000 mm / s and electron beam power 200~1000 W. Of course, since there are usually multiple printed part models, typically 3~5, the processing parameters are as follows. Taking five as an example, in one implementation, the processing settings for the five printed part models are set to "internal scan and fill", and the parameter settings are as follows: (electron beam power 1000W, scan speed 4000 mm / s), (electron beam power 750 W, scan speed 2500 mm / s), (electron beam power 450 W, scan speed 1500 mm / s), (electron beam power 300 W, scan speed 1000 mm / s), (electron beam power 200 W, scan speed 500 mm / s).

[0108] The mesh frame model is selected using "outer contour point scanning" to ensure both powder bed curing and powder bed cracking, while also ensuring the mesh frame model's strength is not too high to minimize thermal deformation to the substrate and facilitate subsequent processing. Based on this, the electron beam power should be as low as possible, ideally between 200 and 300 W. Lower power may result in insufficient heat input, failing to melt the powder. Simultaneously, the scanning speed should not be too fast, as excessive speed leads to severe powder splatter, reduced melting efficiency, and is detrimental to subsequent part processing. A scanning speed of 500–700 mm / s is optimal.

[0109] Furthermore, the parameters of the printed part model need to focus on energy density, i.e., the ratio of scanning speed to electron beam power. Generally, a ratio of 2.5 to 4 is suitable; in other words, low scanning speed requires low electron beam power, and high scanning speed requires high electron beam power. If a low scanning speed and high electron beam power are selected, such as a scanning speed of 500 mm / s and an electron beam power of 1000 W, severe overheating and burning will occur, and the processed part will not conform to the expected shape. If a high scanning speed and low electron beam power are selected, such as a scanning speed of 4000 mm / s and a high electron beam power of 200 W, the heat input will be too low to melt the powder, making processing impossible. In step 3-2, when performing an OR operation between the mesh frame model and the printed part model, the mesh frame model needs to be set as model number 1 to ensure that the mesh frame is processed first, followed by the printed part.

[0110] Step 3-3: Perform additive manufacturing based on the processing parameters to achieve stable forming.

[0111] In step 3-3, before additive manufacturing, the substrate is preheated to 1000~1100°C, for example, 1050°C. Preheating the substrate improves the conductivity of the powder deposited on it, thereby preventing powder bursting or blowing; it also increases the stress on the substrate to prevent cracking.

[0112] In step 3-3, the additive manufacturing includes the following steps: using a scraper to pick up powder, spreading the powder on the substrate, pre-sintering after powder spreading, then processing the grid frame by electron beam "outer contour point scanning", processing the printed parts by "internal scanning filling", thermal compensation before powder spreading, and finally lowering the substrate to a set height to complete one printing process; repeating the operation until the processing height reaches the set printing model height, thus completing the stable forming of the additive manufacturing.

[0113] Furthermore, the pre-sintering process setting requires enabling two functions: "pre-sintering after powder spreading" and "thermal compensation before powder spreading". The parameter settings are as follows: current (35~45) mA, decoking amount (0.4~0.8) V, and time (30~50) s. For example, the parameter settings are as follows: current 40 mA, decoking amount 0.8 V, and time 40 s.

[0114] In this invention, the powder bed is a powder layer formed by melting powder laid on a substrate under the action of an electron beam. The powder used is usually an alloy powder.

[0115] In this invention, the purpose of pre-sintering is to perform preliminary melting of the powder before processing, giving the powder bed a certain strength. The purpose of pre-powder spreading thermal compensation is to keep the powder bed warm after processing, preventing powder blowing due to temperature drop during direct powder spreading. If the current is too high, the decoking amount is too small, and the time is too long, severe powder bed peeling occurs during pre-sintering. Conversely, if the current is too low, the decoking amount is too large, and the time is too short, improper sintering results in severe powder splashing during processing, making subsequent powder spreading extremely prone to powder blowing. The parameters within the above range are suitable.

[0116] Example

[0117] The present invention is further described below through specific examples; however, these examples are merely exemplary and do not constitute any limitation on the scope of protection of the present invention.

[0118] Example 1

[0119] (1) DZ125 alloy powder (particle size between 75~100µm) was kept at 120℃ in a vacuum environment for 10 hours, and a stainless steel substrate with a size of 120 × 120 × 10 mm was prepared. The surface of the stainless steel substrate was polished by a surface grinder, and then ultrasonically cleaned and dried for later use.

[0120] (2) Next, fill the forming chamber of the printing equipment with DZ125 alloy powder, then place the stainless steel substrate in, and adjust the bolts under the stainless steel substrate to keep the upper surface level. Close the equipment door and the vent valve, and start vacuuming. When the vacuum value of the forming chamber of the printing equipment is less than or equal to 5.0 × 10 -3 The vacuum value of the electron beam gun chamber in the forming chamber of the printing equipment is 5.0 × 10⁻⁶ Pa. -4 At Pa, high-purity helium gas is introduced;

[0121] (3) Turn on the high voltage power supply and perform electron beam alignment to ensure that the lower position of the electron beam is in the center of the stainless steel substrate (mark the center position with a marker in advance), and then preheat the stainless steel substrate to 1050°C by electron beam defocusing.

[0122] (4) Establish a mesh frame model

[0123] like Figure 1 As shown, the internal filling primitives are first obtained, and then a first cuboid model with length N4, width N5, and height N6 of 10 mm, 1 mm, and 2 mm respectively is created in the modeling software Solidworks (e.g., Figure 1 (as shown in (a)), then create a second cuboid model with length N5, width N4, and height N6 of 1mm, 10mm, and 2mm respectively (as shown in (a)). Figure 1 (b) As shown, the center coordinates of the two cuboid models are consistent, and they are arranged perpendicularly to each other to obtain the internal filling primitives (such as...). Figure 1 (as shown in (c))

[0124] like Figure 2 As shown, the internal filling primitive array is copied and merged to obtain the internal mesh frame. The internal mesh frame has a length W1, a width W2, and a height W3 of 100 mm, 100 mm, and 2 mm, respectively.

[0125] like Figure 3 As shown, three cuboid models are established. The length N7, width N8, and height N9 of cuboid model M1 are 5, 1, and 2 mm respectively (e.g., ...). Figure 3 (a) As shown, the length N8, width N7, and height N9 of the cuboid model M2 are 1, 5, and 2 mm respectively (as shown in the figure). Figure 3 (b) As shown, the length N7, width N7, and height N9 of the cuboid model M3 are 5, 5, and 2 mm respectively (as shown in the figure). Figure 3 (c) As shown, the three cuboid models are merged to obtain the outer reinforcement element. The outer reinforcement element has external length, width, and height dimensions of 5, 5, and 2 mm, respectively (as shown in Figure 1). Figure 3 (d)

[0126] The outer reinforcement element array is copied to obtain the outer mesh frame, and the inner edge dimensions of the outer mesh frame are consistent with those of the inner mesh frame.

[0127] like Figure 4 As shown, the inner mesh frame is placed inside the outer mesh frame to obtain the mesh frame model;

[0128] (5) Import the mesh frame model and printed part model (built using Solidworks software) established in step (4) into the slicing software. Set the size of the preheating and forming area to 110×110mm. The length and width of the mesh frame model are both 110mm, and the height is 2mm. The length and width of the five printed part models are both 10mm, and the height is 2mm. Their positions are located in the middle of the mesh frame model and are arranged regularly, such as... Figure 6 The location of the printed part model is shown in the figure;

[0129] (6) Set the slice thickness of both the mesh frame model and the printed part model to 0.07 mm, set the melting gap to 0.10 mm, set the rotation angle between slices during printing to 90°, and generate the print file;

[0130] (7) Import the generated print file into the printing operation software. Select "External Contour Point Scan" for the processing settings of the mesh frame model. The parameter settings are as follows: electron beam power 240W, scanning speed 600 mm / s; select "Internal Scan Fill" for the processing settings of the 5 printed part models. The parameter settings are as follows: (electron beam power 1000W, scanning speed 4000 mm / s), (electron beam power 750W, scanning speed 2500 mm / s), (electron beam power 450W, scanning speed 1500 mm / s), (electron beam power 300W, scanning speed 1000 mm / s), (electron beam power 200W, scanning speed 500 mm / s).

[0131] (8) The pre-sintering process settings need to enable the two functions of "pre-sintering after powder spreading" and "thermal compensation before powder spreading". The parameter settings are: current 40mA, decoking amount 0.8V, time 40s;

[0132] (9) Click to start processing. The equipment starts to spread powder, pre-sinter after spreading powder, and then uses DZ125 alloy powder to process the grid frame, print parts and perform thermal compensation before spreading powder. Finally, the forming platform drops by 0.07mm. Among them, it takes about 5 seconds to process a single layer and complete one printing processing cycle. The cycle time is about 100 seconds.

[0133] (10) Repeat step (9), and printing will be completed in about 2 hours. The equipment will automatically stop to cool down, the high voltage power supply will be turned off, the inert gas will be turned off, and the vacuum will be turned off, thus completing the stable forming of alloy electron beam additive manufacturing.

[0134] (11) Opening the warehouse for sampling, the effect of the grid frame printing is as follows Figure 5 As shown, after cleaning the powder bed using high-pressure sandblasting equipment, the effect of the stainless steel substrate and printed parts is displayed as follows. Figure 6 As shown.

[0135] Comparative Example

[0136] Comparative Example 1

[0137] The stable forming of alloy electron beam additive manufacturing was completed in a manner similar to that of Example 1, except that step (4) of establishing the mesh frame model was not performed.

[0138] Finally, the sample was taken from the warehouse, and the printed mesh frame part looked like this. Figure 7 As shown.

[0139] Combination Figure 7 and Figure 5 It is clear that modeling the mesh framework is essential. Without using the mesh framework, directly printing the part model can easily cause the powder bed to crack, leading to powder blowing, ignition failures, and processing failures.

[0140] Comparative Example 2

[0141] The stable forming of alloy electron beam additive manufacturing was completed in a manner similar to that of Example 1, except that in step (4), only the internal grid frame was used as the grid frame model, and its length and width were both 100m.

[0142] Finally, the sample was taken from the warehouse, and the printed mesh frame part looked like this. Figure 8 As shown.

[0143] Combination Figure 8 and Figure 5 It is evident that using only the internal mesh frame as the mesh frame model still results in the problem of powder bed cracking.

[0144] The present invention has been described in detail above with reference to preferred embodiments and exemplary examples. However, it should be noted that these specific embodiments are merely illustrative explanations of the invention and do not constitute any limitation on the scope of protection of the invention. Various improvements, equivalent substitutions, or modifications can be made to the technical content and embodiments of the present invention without departing from the spirit and scope of protection of the invention, and all such modifications fall within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method of additive manufacturing a stable formation, characterized by, The method comprises: Step 1, constructing a grid framework model; Step 2, establishing a printing part model; Step 3, additive manufacturing based on the grid framework model and the printing part model to realize stable forming; the step 1 comprises the following steps: Step 1-1, respectively creating an internal grid framework and a peripheral grid framework; Step 1-2, placing the internal grid framework in the peripheral grid framework to obtain the grid framework model; in step 1-1, the creating of the internal grid framework comprises the following steps: Step 1-1-1, creating an internal filling primitive: by creating a first cuboid model with a length, a width and a height of N4, N5 and N6 respectively, and creating a second cuboid model with a length, a width and a height of N5, N4 and N6, to obtain the internal filling primitive, the center coordinates of the first and second cuboid models are consistent and are arranged perpendicular to each other; Step 1-1-2, array copying the internal filling primitive to obtain the internal grid framework; The creating of the peripheral grid framework comprises the following steps: Step 1-1-1', creating a peripheral strengthening primitive: establishing three cuboid models, wherein the length, width and height of the cuboid model M1 are N7, N8 and N9 respectively, the length, width and height of the cuboid model M2 are N8, N7 and N9 respectively, the length, width and height of the cuboid model M3 are N7, N7 and N9 respectively, and the three cuboid models are combined to obtain the peripheral strengthening primitive; wherein the cuboid model M3 constitutes the outer contour of the peripheral strengthening primitive, and the cuboid model M2 and the cuboid model M1 are cross-nested inside the cuboid model M3; Step 1-1-2', array copying the peripheral strengthening primitive around the internal grid framework to obtain the peripheral grid framework, The peripheral size of the peripheral grid framework is determined according to the size of the substrate, the length of the peripheral grid framework is 8-10mm smaller than the length of the substrate, and the width of the peripheral grid framework is 8-10mm smaller than the width of the substrate.

2. The method of claim 1, wherein, In step 1-1-2, there is no gap between the internal filling primitives.

3. The method of claim 1, wherein, N7> N8.

4. The method of claim 1, wherein, The step 3 comprises the following steps: Step 3-1, importing the grid framework model and the printing part model into slicing software to generate a printing file; Step 3-2, importing the printing file into printing operation software to set the processing parameters of the grid framework model and the printing part model; Step 3-3, additive manufacturing based on the processing parameters to realize stable forming.

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