CN118635529B - Three-dimensional manufacturing method - Google Patents

Abstract

The invention relates to a three-dimensional manufacturing method, which comprises the following steps: determining a conversion area of a solid small melting surface and a solid large melting surface of the part; designing a bracket module for a transition area of the part; taking the part and the bracket module as a whole to perform three-dimensional model design of the part, and performing layer cutting design; and setting printing parameters according to the cutting design parameters, preheating paved powder according to the printing parameters, then scanning and melting, and finally finishing printing of the parts. The support module comprises the upper support module and the lower support module, and the lower support module comprises the positioning support, the basic support and the tip support, so that a good supporting effect is achieved on the printing of the parts, an effect of assisting the complete forming of the parts is achieved, the fact that the size melting surface of the parts does not deviate or shrink is guaranteed, the support module is removed in post-treatment, collapse or buckling deformation of the parts is prevented, and the appearance and performance of the manufactured three-dimensional parts are more excellent.

Description

A three-dimensional manufacturing method

Technical Field

The present invention relates to the technical field of additive manufacturing, and in particular to a three-dimensional manufacturing method.

Background Art

3D printing is an additive manufacturing technology that can realize the direct formation of various structures. It mainly includes three major processes: three-dimensional model design, model segmentation and model printing, and finally completes the printing of parts. 3D printed parts are solidified layer by layer from a two-dimensional plane, and finally form a three-dimensional object with a certain height. Compared with other 3D printing technologies, the heat input of electron beam 3D printing technology is mainly the heat energy provided by the electron beam, and then selective melting is performed according to the structure of the part. The manufacture of physical parts through 3D printing can reduce the preparation process of parts, and can reduce the problems of part deformation, performance degradation or dimensional deviation caused by machining, welding and other processes, so that the parts can be fully formed.

Generally speaking, parts in the fields of civil, military, automobile manufacturing, and aerospace are usually solid, so these fields have higher requirements for the physical properties of parts. In addition, parts in the medical field may include porous structures, so these fields have stricter requirements for the compression properties of parts, especially orthopedic implants.

For parts that only contain entities, higher dimensional accuracy is often required. For example, the dimensional accuracy requirement for the surface that needs to be processed may be ±0.5mm, and the dimensional accuracy requirement for the surface that does not need to be processed must reach ±0.05mm. However, the actual printed parts face the transformation of the large and small melting surfaces of the entity, resulting in poor actual forming effects, and usually the small melting surface will partially shrink or shift. The main reason is that the transformation of the melting surface causes the thermal field of the part to fluctuate, and the energy of the large melting surface continues to extend, resulting in the phenomenon that the small melting surface shifts toward the center of the large melting surface, or the large melting surface attracts the small melting surface to move closer to the center.

In the related art, the performance of parts can be improved by thickening the thickness of the solid part, but the material of the thickened part needs to be machined, and the remaining material after machining can only be scrapped.

The preparation of parts is achieved through 3D printing technology, and the parts need to be provided with a support module to realize the forming of the parts to prevent the parts from collapsing or warping. However, the structure of the support model designed in the prior art can only solve part of the problem and cannot solve the above problems well.

Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

It should be noted that this section is intended to provide background or context for the technical solutions of the present invention stated in the claims. The description herein is not admitted to be prior art by inclusion in this section.

Summary of the invention

An object of the present invention is to provide a three-dimensional manufacturing method, thereby solving one or more problems caused by limitations and defects of the related art at least to a certain extent.

The present invention provides a three-dimensional manufacturing method, comprising the following steps:

Determine a transition region between a solid small melting surface and a solid large melting surface of a part, wherein a section area of the solid small melting surface is smaller than a section area of the solid large melting surface, a connection structure is provided between the solid small melting surface and the solid large melting surface, the solid large melting surface has a suspended structure, and the transition region includes the connection structure and the suspended structure;

A support module is designed for the conversion area of the part, wherein the support module includes: an upper support module and a lower support module; the upper support module is located above the entity large melting surface corresponding to the connection structure; the lower support module includes: a positioning support, a basic support and a tip support, the positioning support and part of the basic support are located below the entity small melting surface, the tip support and part of the basic support are located below the suspended structure of the entity large melting surface, and the upper end of the tip support is connected to the lower surface of the entity large melting surface, and the lower end of the tip support is connected to the basic support;

Taking the part and the bracket module as a whole, designing a three-dimensional model of the part and performing a layer design;

The printing parameters are set according to the layer design parameters, the laid powder is preheated according to the printing parameters, and then scanned and melted to finally complete the printing of the part.

In the present invention, the step of determining the transition area between the solid small melting surface and the solid large melting surface of the part comprises:

The slice areas of the part are compared and analyzed, and when the areas of two adjacent slices reach a preset condition, the part where the two adjacent slices are located is determined to be the conversion area.

In the present invention, the preset condition is that the area of one of the slices is greater than or equal to twice the area of the other slice.

In the present invention, the cross-sectional areas of the upper bracket module and the positioning bracket decrease in a step-like manner; the cross-sectional areas of the upper bracket module and the positioning bracket are 0.1-100 mm ² , and the heights are 1-50 mm.

In the present invention, the cross-sections of the upper bracket module and the positioning bracket are circular or polygonal.

In the present invention, the cross-sectional area of the tip support is 0.1-0.5 mm ² , and the height is 0.1-2 mm; the cross-sectional area of the base support is 0.1-30 mm ² , and the height is 0.1-50 mm ² .

In the present invention, the step of setting printing parameters according to the slice design parameters and preheating the laid powder according to the printing parameters includes:

The powder is laid after preheating the substrate;

The powder on the substrate is preheated, wherein the powder within a preset range of the support module and its periphery is not preheated.

In the present invention, the preset range around the bracket module is a range of 5 to 20 mm from the outer side of the bracket module.

In the present invention, a thermal compensation process is performed during the scanning and melting process of the parts, and the parameters of the thermal compensation process are: a high-energy beam current of 10-50 mA and a compensation time of 1-20 s.

In the present invention, the thermal compensation process is to scan and melt the powder outside the range of 5 to 20 mm on the outer side of the support module.

The technical solution provided by the present invention may include the following beneficial effects:

In the present invention, through the above method, a support module is designed for the conversion area between the solid small melting surface and the solid large melting surface of the part, and the support module includes an upper support module and a lower support module, and the lower support module includes a positioning support, a base support and a tip support. The support module designed in this application not only plays a good supporting role in the printing of parts, but also plays a role in assisting the complete forming of parts, ensuring that the large and small melting surfaces of the parts do not deviate or shrink, but also realizes the removal of the support module in post-processing, preventing the parts from collapsing or warping, and the appearance and performance of the obtained three-dimensional parts are more excellent.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

FIG1 is a schematic flow chart showing a three-dimensional manufacturing method in an exemplary embodiment of the present invention;

FIG2 is a schematic diagram showing the positional relationship between the physical size melting surface and the support module in an exemplary embodiment of the present invention;

FIG. 3 shows a flow chart of setting printing parameters according to slice design parameters and preheating the laid powder according to the printing parameters in an exemplary embodiment of the present invention.

Reference numerals:

100. small solid melting surface; 200. large solid melting surface; 201. suspended structure; 300. bracket module; 301. upper bracket module; 302. lower bracket module; 3021. positioning bracket; 3022. basic bracket; 3023. tip bracket.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present invention will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In addition, the accompanying drawings are only schematic illustrations of embodiments of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and their repeated descriptions will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

The technical solution of this application aims to change the shrinkage and deformation problem of parts during the cooling process. Specifically, during the cooling process, the parts will shrink toward the center of the thermal field energy, which is consistent with the principle of thermal expansion and contraction. For parts whose melting surfaces do not change much, they will shrink evenly during the cooling process, and the shrinkage sizes of multiple surfaces are almost the same. The appearance after cooling is no different from the appearance at high temperature. During the electron beam 3D printing process, such parts only need to scale the model to obtain parts consistent with the model size.

However, for parts with transitions between large and small melting surfaces, the small melting surface will shift toward the center of the large melting surface. The small melting surface is affected by the large melting surface. The closer the small melting surface is to the large melting surface, the greater the impact, and the greater the corresponding shrinkage during the cooling process. The farther the small melting surface is from the large melting surface, the less impact it has, and the smaller the shrinkage during the cooling process, which eventually leads to partial distortion of the part. In the prior art, such parts cannot be printed by setting a certain scale, and can only be printed by adding a lot of processing allowances during the model processing process, and finally the final product is prepared by mechanical processing, but this method is extremely wasteful.

In view of the above problems, a three-dimensional manufacturing method is provided in this exemplary embodiment. Referring to FIG. 1 , the three-dimensional manufacturing method includes the following steps:

Step S101: Determine the transition area between the physical small melting surface 100 and the physical large melting surface 200 of the part. The cross-sectional area of the physical small melting surface 100 is smaller than the cross-sectional area of the physical large melting surface 200. The cross-sectional area here is the cross-sectional area of the part in the horizontal direction after the part is printed and placed.

Please refer to FIG2 , the transition area between the entity small melting surface 100 and the entity large melting surface 200 is also the entity large and small melting surface transition area. The size of the entity melting surface is determined according to the section area. The entity small melting surface 100 has a smaller section area, and the entity large melting surface 200 has a larger section area. There is a connection structure between the entity small melting surface 100 and the entity large melting surface 200, that is, the entity small melting surface 100 and the entity large melting surface 200 are connected together, and there is an overlap between them. The entity large melting surface 200 has a suspended structure 201, and the conversion area includes the connection structure and the suspended structure 201.

Step S102: Designing a support module 300 for the conversion area of the part.

Wherein, please continue to refer to FIG. 2 , the support module 300 includes: an upper support module 301 and a lower support module 302. The upper support module 301 is located above the entity large melting surface 200 corresponding to the connection structure. The lower support module 302 includes: a positioning support 3021, a basic support 3022 and a tip support 3023. The positioning support 3021 and part of the basic support 3022 are located below the entity small melting surface 100, the tip support 3023 and part of the basic support 3022 are located below the suspended structure 201 of the entity large melting surface 200, and the upper end of the tip support 3023 is connected to the lower surface of the entity large melting surface 200, and the lower end of the tip support 3023 is connected to the basic support 3022.

It should be noted that in order to show the positional relationship between the positioning bracket 3021 and the basic bracket 3022 below the small physical melting surface 100, the relative positional relationship between the positioning bracket 3021 and the basic bracket 3022 below the small physical melting surface 100 is not blocked in FIG. 2.

Step S103: Design a three-dimensional model of the part and the support module 300 as a whole, and perform slice design.

Step S104: setting printing parameters according to the slice design parameters, preheating the laid powder according to the printing parameters, and then scanning and melting it to finally complete the printing of the part.

Through the above method, a support module 300 is designed for the conversion area of the small solid melting surface 100 and the large solid melting surface 200 of the part, and the support module 300 includes an upper support module 301 and a lower support module 302, and the lower support module 302 includes a positioning support 3021, a base support 3022 and a tip support 3023. The support module 300 designed in the present application not only plays a good supporting role in the printing of the part, but also plays a role in assisting the complete forming of the part, which not only ensures that the large and small melting surfaces of the part do not deviate or shrink, but also realizes the removal of the support module 300 in the post-processing, prevents the part from collapsing or warping, and the appearance and performance of the obtained three-dimensional part are more excellent.

It should be noted that the steps for determining the transition area between the physical small melting surface 100 and the physical large melting surface 200 of the part are specifically as follows:

Compare and analyze the slice areas of the part, and when the areas of two adjacent slices reach a preset condition, the part where the two adjacent slices are located is determined to be a solid size melting surface conversion area. The preset condition is that the area of one slice is greater than or equal to twice the area of the other slice.

In this embodiment, the entity size melting surface conversion area of the part is specifically defined. When the area difference between the two slices is large, that is, the area of one slice is greater than or equal to twice the area of the other slice, the parts of the part corresponding to the two layers are identified as the entity size melting surface conversion area. For example, the part corresponding to the entity large melting surface 200 is a flat rectangular parallelepiped, and the part corresponding to the entity small melting surface 100 is a higher rectangular parallelepiped or cube, but the slice area of the entity large melting surface 200 is more than twice the slice area of the entity small melting surface 100. It should be noted that the determination of the size melting surface does not require the determination of the height of the part parts to which they correspond, but only requires the comparison of the areas of the two interconnected slices.

It can be understood that the cross-sectional areas of the upper support module 301 and the positioning support 3021 involved in the above embodiment decrease in a step-like manner; the cross-sectional area of the upper support module 301 and the positioning support 3021 is 2.5 mm ² and the height is 10 mm.

Optionally, in some embodiments, the cross-section of the upper bracket module 301 and the positioning bracket 3021 is circular or polygonal, for example, may be composed of a plurality of cylinders, a plurality of cuboids, or a plurality of cubes.

In addition, optionally, the cross-sectional area of the tip bracket 3023 is 0.1-0.5 mm ² and the height is 0.1-2 mm; the cross-sectional area of the base bracket 3022 is 1.5 mm ² and the height is 10 mm. The tip bracket 3023 is connected to the parts and has a small cross-sectional area, which is easy to remove during post-processing.

Based on the above embodiment, the step of setting the printing parameters according to the slice design parameters and preheating the laid powder according to the printing parameters, please refer to FIG. 3, includes:

S201, preheating the substrate and then laying powder;

S202, preheating the powder on the substrate, wherein the powder within a preset range of the support module 300 and its periphery is not preheated.

The preset range around the bracket module 300 is 5 to 20 mm from the outer side of the bracket module 300. The bracket module 300 and the powder around it are not preheated in order to reduce the strength of the bracket module 300 and the connection strength between the bracket module 300 and the parts, so as to facilitate the removal of the bracket module 300 during post-processing and reduce damage to the surface of the parts.

On the basis of the above embodiments, a thermal compensation process is performed during the scanning and melting of the parts, and the parameters of the thermal compensation process are: a high energy beam current of 10-50 mA, such as 20 mA, 30 mA, etc., and a compensation time of 1-20 s, such as 5 s, 10 s, 15 s, etc. Further, the thermal compensation process is to scan and melt the powder outside the range of 5-20 mm of the outer side surface of the support module 300, such as 10 mm, 15 mm, etc., but it is not limited thereto.

The three-dimensional manufacturing method of the present application is described in more detail below.

1. Determine the specific structure of the part, focusing on the location of the entity size melting surface conversion area.

2. Bracket module 300 design

The corresponding support module 300 is designed according to the placement position of the parts, and the support module 300 includes an upper support module 301 and a lower support module 302. Among them, the lower support module 302 includes: a positioning support 3021, a basic support 3022 and a tip support 3023.

The design of the structural parameters of the support module 300 can ensure that it is easy to remove during post-processing and will not stick to the entity. The upper support module 301 mainly plays a connecting and positioning role and is set at the conversion position of the entity's large and small melting surface. The upper support module 301 can be composed of multiple columns with different cross-sectional areas, such as a cylinder and a cube. The lower support module 302 mainly plays a supporting role. The lower support module 302 needs to be set with a cutting thickness, and 0.01~1mm is the preferred range.

The height of the upper support module 301 can be designed according to the height of the positioning support 3021 in the lower support module 302. The upper support module 301 and the positioning support 3021 are preferably cubes, and the three-dimensional dimensions (x, y, z) of the cube are calculated by the large and small melting surfaces. If the entity small melting surface 100 is a rectangular structure, wherein the length and width of the entity small melting surface 100 are respectively a ₁ and b ₁ , and the length and width of the entity large melting surface 200 are respectively a ₂ and b ₂ , and the offsets in the length and width directions are α and β, then:

x=α/10, α=(a ₂ -a ₁ )/2

y=β/10, β=(b ₂ -b ₁ )/2

z=e×µ

µ = (c × d) / 10 ⁴ × λ ₁

Where, e is the continuous printing height of the solid large melting surface 200, c is the distance in the long direction of the molding area, d is the distance in the wide direction of the molding area, all in mm, λ ₁ is the empirical parameter of the bracket, the empirical parameter of the bracket of the electron beam 3D printing equipment is 0.5, and µ is the shrinkage. If the calculated value of (x, y, z) is less than 1 mm, it is set as 1 mm.

3. Parts printing

(1) The parts and the support module 300 are combined into an assembly, and finally the printing process is set according to the cutting result.

During the assembly process, the model details need to be repaired to prevent gaps or discontinuities, and finally the printing process is set according to the segmentation results. The printing process parameters need to be designed according to the part process parameters, and the printing process needs to set the powder thickness, defocus, and preheating process. The powder thickness is preferably in the range of 0.01~0.30mm, and the defocus is preferably in the range of -0.4~0V.

(2) Cut the 3D model of the assembly into pieces and import it into the printing control software, setting up the pre-printing preparations, including vacuum degree, inert gas, preheating temperature, etc.

(3) Printing process parameters are set according to the structure of the assembly, wherein the powder within the preset range of the support module 300 and its surroundings is not preheated.

(4) The substrate is preheated to the set temperature and printing begins. The powder thickness, defocus amount and thermal compensation process need to be set. The lower beam is focused for selective melting, and the powder is spread and the lower beam is maintained at the temperature. Thermal compensation is performed during the printing process, and the parameters of the thermal compensation process need to be designed according to the data of the large and small melting surfaces.

If the area of the small melting surface 100 of the entity is less than 10mm ² , the thermal compensation amount needs to be reduced, and the thermal compensation parameters are 10-15mA and 1-5s as the optimal range; if the area of the small melting surface 100 of the entity is 10-50mm ² , the thermal compensation amount needs to be appropriately reduced, and the thermal compensation parameters are 15-25mA and 5-8s as the optimal range; if the area of the small melting surface 100 of the entity is 100-500mm ² , the thermal compensation amount needs to be slightly reduced, and the thermal compensation parameters are 25-50mA and 8-12s as the optimal range. The smaller the small melting surface 100 of the entity is, the more quenching is required, that is, fixing is performed through less thermal compensation.

If the area of the large solid melting surface 200 is 500-1000mm ² , the thermal compensation parameters are 25-50mA and 8-12s as the optimal range; if the area of the large solid melting surface 200 is 1000-3000mm ² , the thermal compensation parameters are 15-25mA and 5-8s as the optimal range; if the area of the large solid melting surface 200 is greater than 3000mm ² , the thermal compensation parameters are 10-15mA and 1-5s as the optimal range. The larger the large solid melting surface 200 is, the less quenching is needed. During the melting process of the large solid melting surface 200, the smaller the thermal compensation is, the better.

In the process of defocusing and beam lowering, the thermal compensation parameters are 10-50mA and 1-20s as the optimization interval. The thermal compensation methods are mainly divided into two groups, one group is the area far away from the part support module 300, which is preheated; the other group is the area close to the part support module 300, and the non-support area is preheated, and the lowest preheating parameters should be used. The preheating method is designed according to the shape of the support module 300. The areas with a distance of 5-20mm on both sides of the support module 300 are all non-preheating areas. The non-support areas can overlap at corners. If the support module 300 is dot-shaped, the non-support area is circular with a diameter of 5-20mm.

(5) Repeat the process of focusing the beam to select the melting area, spreading the powder, and defocusing the beam to maintain the temperature for printing layer by layer, and finally complete the printing of the part.

(6) After printing is completed, the vacuum needs to be maintained for a certain period of time and then slowly filled with inert gas.

The vacuum maintenance time t is calculated by the following formula:

t ₁ =a/50×µ

_t2 =b/24×µ

µ = (c × d) / 10 ⁴ × λ ₂

Where _t1 is the vacuum maintenance time determined by the printing height, _t2 is the vacuum maintenance time determined by the printing time, and the vacuum maintenance time t is the smaller value of _t1 and _t2 , in h. Where a is the total printing height of the part, in mm, b is the total printing time of the part, in h, c is the long distance of the molding area, d is the wide distance of the molding area, in mm, _λ2 is the cooling experience parameter, and the cooling experience parameter of the electron beam 3D printing equipment is 5.

Maintaining the vacuum for a certain period of time prevents the parts from shifting out of position during the cooling process.

A suitable printing process can not only complete the forming of the parts, but also ensure that the forming quality inside the parts is good, without pores, cracks and inclusions.

The three-dimensional manufacturing method of the present application is described below through a specific test example.

A model is designed for a platform (hereinafter referred to as the platform) used in the communications industry and its performance is improved through electron beam 3D printing. The printing material is titanium alloy with a powder particle size of 50-150μm.

Step 1: First determine the structure of the platform and whether there are large and small melting surfaces.

Step 2: The support module 300 is divided into an upper support module 301 and a lower support module 302, both of which need to be set with corresponding heights and cutting thicknesses. The tip support 3023 is linear, and the diameter of the linear support from the top of the base support 3022 to the part support surface is 0.1 mm and the height is 1 mm; the positioning support 3021 is a cube, in which the solid small melting surface 100 is a rectangular structure, in which the length and width of the solid small melting surface 100 are 5 mm and 10 mm respectively, the length and width of the solid large melting surface 200 are 30 mm and 50 mm respectively, and the height of the solid large melting surface 200 is 20 mm. Therefore, the offsets in the length and width directions are 12.5 mm and 20 mm respectively, and it is obtained that (x, y, z) are (1.2, 2, 20) respectively, and the cutting thickness is 0.05 mm.

The upper bracket module 301 is a columnar or quasi-columnar body and is configured according to the structure of the parts. The upper bracket module 301 is preferably a three-section cube. The (x, y, z) of the first section of the cube is (2.4, 4, 10), the (x, y, z) of the second section of the cube is (2, 3, 5), and the (x, y, z) of the third section of the cube is (1.5, 2, 5). Finally, the lower bracket module 302, the upper bracket module 301 and the positioning bracket 3021 are merged into a whole, and the slice thickness is 0.05 mm.

Step 3: Finally, the parts and the support module 300 are combined as a platform, and the defective parts in the parts are repaired to confirm that the model is complete and defect-free. The platform assembly is cut according to the preset slice thickness and imported into the printing control software, and the pre-printing preparation is set. High-purity helium (≥99.9%) is filled and vacuumed simultaneously. The ultimate vacuum degree is 2.0×10 ^{- 2} Pa, the power supply high voltage is stabilized to 60KV, the substrate preheating temperature is 700℃, and the printing process parameters are set according to the structure of the assembly. The physical process is 27mA, 6m/s, and the defocus is -0.2V.

The substrate is preheated to 700℃ by the lower beam to start printing. The electron beam is focused to achieve selective melting after slicing. After the selective melting, the defocused lower beam is used to maintain the printing temperature. The lower beam power and time are 20mA and 7s. After the powder is spread, the defocused lower beam is used to pre-sinter the powder. The lower beam power and time are 15mA and 10s.

The thermal compensation method includes two groups. One group is for preheating the area away from the part support module 300; the other group is for preheating the non-support area close to the part support module 300, and the minimum preheating parameters are 15mA and 6s. The preheating method is designed according to the shape of the support module 300. The support module 300 is a block support, and the position about 5mm away from the support module 300 is the non-preheating area. The non-support area can overlap when encountering a corner.

Then, the electron beam is repeatedly focused for selective melting, and after the powder is spread, the beam is defocused to maintain the printing temperature, wherein the powder thickness is 0.05mm and the defocus amount is -0.2V, until the printing process is completed. Automatically cool to room temperature, open the device to take out the parts and remove the bracket module 300, and the corresponding parts can be obtained.

It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like that may appear in the above description indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the embodiments of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present invention are indicated by the appended claims.

Claims (5)

1. A method of three-dimensional manufacturing comprising the steps of:

Determining a conversion area of a solid small melting surface and a solid large melting surface of a part, wherein the tangential area of the solid small melting surface is smaller than that of the solid large melting surface, a connecting structure is arranged between the solid small melting surface and the solid large melting surface, the solid large melting surface is provided with a suspension structure, and the conversion area comprises the connecting structure and the suspension structure;

Designing a bracket module for the transition region of the part, wherein the bracket module comprises: an upper bracket module and a lower bracket module; the upper bracket module is positioned above the solid large melting surface corresponding to the connecting structure; the lower bracket module includes: the device comprises a positioning bracket, a basic bracket and a tip bracket, wherein the positioning bracket and part of the basic bracket are positioned below a solid small melting surface, the tip bracket and part of the basic bracket are positioned below a suspension structure of the solid large melting surface, the upper end of the tip bracket is connected with the lower surface of the solid large melting surface, and the lower end of the tip bracket is connected with the basic bracket;

Taking the part and the bracket module as a whole to perform three-dimensional model design of the part, and performing layer cutting design;

setting printing parameters according to the cutting layer design parameters, preheating paved powder according to the printing parameters, then scanning and melting, and finally finishing printing of the parts;

The step of determining the transition area of the solid small melt surface and the solid large melt surface of the part comprises:

Comparing and analyzing the cut areas of the parts, and judging that the part parts where the two adjacent cut layers are positioned are the conversion areas when the areas of the two adjacent cut layers reach preset conditions;

the preset conditions are as follows: the area of one cutting layer is more than or equal to 2 times of the area of the other cutting layer;

The cross section areas of the upper bracket module and the positioning bracket are decreased in a step manner; the cross section areas of the upper bracket module and the positioning bracket are 0.1-100 mm ², and the height is 1-50 mm;

the cross sections of the upper bracket module and the positioning bracket are circular or polygonal;

The cross section area of the tip support is 0.1-0.5 mm ², and the height of the tip support is 0.1-2 mm; the cross section area of the basic support is 0.1-30 mm ², and the height is 1-50 mm.

2. The three-dimensional manufacturing method according to claim 1, wherein the step of setting printing parameters according to the cut layer design parameters, and preheating the laid powder according to the printing parameters, comprises:

preheating a substrate and then paving powder;

the powder on the substrate is preheated, wherein the powder within the preset range of the bracket module and the periphery thereof is not preheated.

3. The three-dimensional manufacturing method according to claim 2, wherein the preset range of the periphery of the bracket module is a range of 5-20 mm from the outer side surface of the bracket module.

4. A three-dimensional manufacturing method according to any one of claims 1-3, characterized in that a thermal compensation process is performed during the part scanning and melting, the parameters of the thermal compensation process being: the high energy beam current is 10-50 mA, the compensation time is 1-20 s.

5. The method according to claim 4, wherein the thermal compensation treatment is to scan and melt the powder outside the range of 5-20 mm on the outer side of the stent module.