CN114769615B - Metal 3D printing method without supporting structure - Google Patents
Metal 3D printing method without supporting structure Download PDFInfo
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- CN114769615B CN114769615B CN202210070184.3A CN202210070184A CN114769615B CN 114769615 B CN114769615 B CN 114769615B CN 202210070184 A CN202210070184 A CN 202210070184A CN 114769615 B CN114769615 B CN 114769615B
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- transition layer
- printing
- workpiece
- transition
- thickness
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- 239000002184 metal Substances 0.000 title claims abstract description 25
- 238000000034 method Methods 0.000 title claims abstract description 25
- 238000010146 3D printing Methods 0.000 title claims abstract description 24
- 230000007704 transition Effects 0.000 claims abstract description 114
- 238000007639 printing Methods 0.000 claims abstract description 48
- 238000009825 accumulation Methods 0.000 claims abstract description 7
- 238000005245 sintering Methods 0.000 claims abstract description 5
- 239000000725 suspension Substances 0.000 claims abstract description 5
- 230000000750 progressive effect Effects 0.000 claims abstract description 3
- 239000000758 substrate Substances 0.000 claims description 10
- 238000010438 heat treatment Methods 0.000 claims description 4
- 238000003754 machining Methods 0.000 abstract description 3
- 230000035882 stress Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 230000008646 thermal stress Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
- B22F10/20—Direct sintering or melting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
- B22F10/30—Process control
- B22F10/36—Process control of energy beam parameters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y10/00—Processes of additive manufacturing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y80/00—Products made by additive manufacturing
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Automation & Control Theory (AREA)
- Mechanical Engineering (AREA)
- Powder Metallurgy (AREA)
Abstract
The invention relates to a method for printing a non-support structure by metal 3D, which comprises the steps of designing a transition layer for overcoming stress accumulation at a suspension structure position according to suspension structure characteristics of a workpiece and progressive stress accumulation in a printing process, wherein the transition layer is used as a part of a printing workpiece, and the printing workpiece comprises a workpiece body and the transition layer; and (3) adjusting the printing sequence of each region of the workpiece through the 3D printing equipment, and sequentially forming according to the sequence of the workpiece body and the transition layer, wherein the transition layer printing mode adopts a long vector sintering mode. The addition of the support is canceled, the printing cost is reduced, the support is not required to be removed after the printing is finished, and the process of removing the support is omitted. In addition, the existing part which cannot be additionally supported for one-step forming can be directly formed, the printing cost is reduced, the machining allowance is reduced, and the delivery period of the workpiece is shortened.
Description
Technical Field
The invention relates to a 3D printing technology, in particular to a metal 3D printing method without a supporting structure.
Background
The 3D printing technology is currently widely used in various aspects such as medical treatment, fashion, industry, aerospace, etc. Metal 3D printing technology has found deep application in the field of the mold industry. Metal 3D printing requires complete melting of the metal powder, direct molding of the metal part, and thus requires a high power laser as an energy source. Before the laser starts scanning, metal powder is paved on a printing substrate, and then the laser beam selectively melts the powder on the substrate according to the contour information of the current layer to process the shape of the current layer. And finishing the printing task of the next layer thickness by the current layer, and processing the next layer by layer until the whole part is processed. Because of this particular forming process, the workpiece undergoes multiple rapid cooling and rapid heating during the forming process, and the residual thermal stress within the workpiece is significant.
According to the gravity principle, if the angle between a certain surface of an object and a vertical line is larger than 45 degrees and the object is suspended, the falling is likely to happen. For 3D printing, the 45 ° rule still exists. Although the metal material is melted in the printing process, certain adhesiveness can appear, but the thermal stress and deformation of the workpiece per se aggravate the printing difficulty of the 45 DEG overhang structure, and when the cantilever structure is collapsed and deformed seriously in the printing process, the forming is failed. At present, aiming at collapse in the cantilever structure process, a supporting structure is added below the cantilever to assist forming. And (5) after the forming of the workpiece is finished, removing the supporting structure. The addition of the support can greatly ensure the forming of the part, but also increases the printing cost of the workpiece. In addition, the removal of the support takes a considerable time and cost. The final point is that some cantilever structures are not supported, and these non-supported features must be discarded or modified according to the 45 rule, such as by adjusting the feature angle to 50, and finally modifying the part feature by machining.
Disclosure of Invention
Aiming at the structural workpiece with the cantilever angle smaller than 45 degrees in the metal 3D printing structure, the forming requirement is met by adopting a mode of adding a support or modifying the characteristic angle of the cantilever, the time and the material consumption are reduced, and the metal 3D printing method without the support structure is provided.
The technical scheme of the invention is as follows: the metal 3D printing method without the support structure specifically comprises the following steps of:
1) Structural design: according to the suspended structural characteristics of the workpiece and progressive stress accumulation in the printing process, designing a transition layer for overcoming the stress accumulation at the suspended structural position, wherein the transition layer is used as a part of the printed workpiece, and the printed workpiece comprises a workpiece body and the transition layer;
2) Setting printing parameters:
the printing power of the transition layer is 100-300W, the printing speed is 1000-2000 mm/s, and the scanning interval is 0.06-0.12 mm;
3) Forming a workpiece:
adjusting the printing sequence of each region of the workpiece through 3D printing equipment, and sequentially forming according to the sequence of the workpiece body and the transition layer, wherein the heating temperature of the substrate is 150-200 ℃;
the transition layer printing mode adopts a long-vector sintering mode.
The included angle between the suspended structure and the printing substrate in the suspended workpiece is theta, the number of transition layers is more than or equal to 1, and the smaller the suspension angle is, the more the number of transition layers is;
when the number of the transition layers is more than 1, the transition layers at the farthest end of the cantilever are sequentially printed from inside to outside, and finally the first transition layer closest to the edge structure is printed.
The metal 3D printing support-free structure part is obtained by printing a metal 3D printing method without a support structure, and the metal 3D printing support-free structure part comprises a printing workpiece body, and further comprises transition layers, wherein an included angle between a suspended structure and a printing substrate in the suspended workpiece is theta, the number of transition layers is more than or equal to 1 along with the design of the body structure, and the thickness range of the transition layers is 0.5-3 mm.
Preferably, when the overhang angle is more than or equal to 30 degrees, the number of the transition layers is 1, and the thickness is 0.5-1.5 mm.
Preferably, when the overhang angle is less than or equal to 30 degrees and less than or equal to 20 degrees, the number of the transition layers is set to 2-3, the transition layer closest to the edge is a first transition layer, the transition layers far away from the edge of the cantilever are sequentially a second transition layer and a third transition layer; the thickness of the first transition layer is 0.5-1.0 mm, the thickness of the second transition layer is set to be 1.0-1.5 mm, and the thickness of the third transition layer is set to be 1.0-1.5 mm.
Preferably, when the overhang angle is less than 20 degrees and less than or equal to 10 degrees, the number of the transition layers is set to be 4-5, the transition layer closest to the edge is a first transition layer, and the transition layers far away from the edge of the cantilever are sequentially a second transition layer, a third transition layer, a fourth transition layer and a fifth transition layer; the thickness of the first transition layer is 0.5-1.0 mm, the thickness of the second transition layer is set to 0.5-1.0 mm, the thickness of the third transition layer is set to 1.0-1.5 mm, the thickness of the fourth transition layer is set to 1.0-1.5 mm, and the thickness of the fifth transition layer is set to 1.0-1.5 mm.
The invention has the beneficial effects that: according to the metal 3D printing method without the support structure, the addition of the support is canceled, the printing cost is reduced, the support is not required to be removed after printing is finished, and the process of removing the support is omitted. In addition, the existing part which cannot be additionally supported for one-step forming can be directly formed, the printing cost is reduced, the machining allowance is reduced, and the delivery period of the workpiece is shortened.
Drawings
FIG. 1 is a flow chart of a method of metal 3D printing without a support structure according to the present invention;
fig. 2 is a schematic diagram-front view of a transition layer in a metal 3D printing method without a supporting structure according to the present invention.
Detailed Description
The invention will now be described in detail with reference to the drawings and specific examples. The present embodiment is implemented on the premise of the technical scheme of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following examples.
The metal 3D printing method flow chart without the supporting structure shown in fig. 1 specifically comprises the following steps:
1. structural design:
according to the structural characteristics of the suspended piece, a transition layer with a certain thickness is designed. The workpiece as described in fig. 2, the suspended structure and the printing substrate have an included angle θ, and in order to ensure that the workpiece is shaped normally, the suspended position is divided into a multi-part transition structure, and the transition layer is used as a part of the printing workpiece. The transition layer has a certain thickness, and the thickness range is 0.5 mm-3 mm. The number of the transition layers is more than or equal to 1, and the smaller the overhang angle is, the more the number of the transition layers is.
The transition layer reduces the accumulation of printing stress while ensuring self-forming in order to reduce the influence of printing stress on the formed entity of the lower layer. The structure of the transition layers is designed according to the shape of the workpiece, and when the overhang angle is more than or equal to 30 degrees, the number of the transition layers is 1, and the thickness is 0.5-1.5 mm; when the overhang angle is less than 30 degrees and less than or equal to 20 degrees, the number of transition layers can be set to be 2-3, the transition layer closest to the edge is transition layer 1, the transition layers far away from the edge of the cantilever are sequentially set to be 2,3, the thickness of the transition layer 1 is 0.5-1.0 mm, the thickness of the transition layer 2 is set to be 1.0-1.5 mm, and the thickness of the transition layer 3 is set to be 1.0-1.5 mm; when the overhang angle is less than 20 degrees and less than or equal to 10 degrees, the number of transition layers can be set to be 4-5, the transition layer closest to the edge is transition layer 1, the transition layers far away from the edge of the cantilever are sequentially set to be 2,3,4 and 5, the thickness of the transition layer 1 is 0.5-1.0 mm, the thickness of the transition layer 2 is set to be 0.5-1.0 mm, the thickness of the transition layer 3 is set to be 1.0-1.5 mm, the thickness of the transition layer 4 is set to be 1.0-1.5 mm, and the thickness of the transition layer 5 is set to be 1.0-1.5 mm; when the number of the transition layers is more than 1, the overlapping area between the transition layers is 0.1-0.4 mm.
2. Setting printing parameters:
the printing power of the transition layer is 100-300W, the printing speed is 1000-2000 mm/s, and the scanning interval is 0.06-0.12 mm.
When the number of the transition layers is 1, the printing power of the transition layers is 150-220W, the printing speed is 1200-2000 mm/s, and the scanning interval is 0.08-0.10 mm; when the number of the transition layers is more than 1, the energy density of the transition layer 1 needs to be the lowest, the energy density of the transition layer 2 is higher than that of the transition layer 1, the energy density of the transition layer 3 is higher than that of the transition layer 2, and so on.
The transition layer parameters are printed by adopting a long-vector sintering mode.
3. Workpiece forming
And (3) adjusting the printing sequence of each region of the workpiece through the 3D printing equipment, and sequentially realizing forming according to the sequence of the first workpiece body and the later transition layer. The heating temperature of the substrate is 150-200 ℃.
The transition layer sintering sequence, when the transition layer quantity is more than 1, the printing sequence starts from the farthest end of the cantilever to the transition layer 1 in sequence.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (5)
1. The metal 3D printing method without the support structure is characterized by comprising the following steps of:
1) Structural design: according to the suspended structural characteristics of the workpiece and progressive stress accumulation in the printing process, designing a transition layer for overcoming the stress accumulation at the suspended structural position, wherein the transition layer is used as a part of the printed workpiece, and the printed workpiece comprises a workpiece body and the transition layer;
2) Setting printing parameters:
the printing power of the transition layer is 100-300W, the printing speed is 1000-2000 mm/s, and the scanning interval is 0.06-0.12 mm;
3) Forming a workpiece: adjusting the printing sequence of each region of the workpiece through 3D printing equipment, and sequentially forming according to the sequence of the workpiece body and the transition layer, wherein the heating temperature of the substrate is 150-200 ℃;
the transition layer printing mode adopts a long vector sintering mode;
the included angle between the suspended structure in the workpiece and the printing substrate is a suspension angleθThe number of the transition layers is more than or equal to 1, and the smaller the overhang angle is, the more the number of the transition layers is;
when the number of the transition layers is more than 1, the transition layer at the farthest end of the cantilever of the suspended structure starts to print sequentially from outside to inside, and finally the first transition layer closest to the edge of the cantilever of the suspended structure is printed.
2. A metal 3D printed unsupported structural part obtained by printing using a metal 3D printing method of a unsupported structure as claimed in claim 1, the unsupported structural part comprising a transition in addition to a printed workpiece bodyThe included angle between the suspended structure in the workpiece and the printing substrate is a suspension angleθThe position of the suspended structure is internally provided with more than or equal to 1 transition layer along with the structure of the body, and the thickness range of the transition layer is 0.5 mm-3 mm.
3. The metal 3D printed unsupported structural part of claim 2, wherein the number of transition layers is 1 and the thickness is 0.5-1.5 mm when the overhang angle is equal to or greater than 30 °.
4. The metal 3D printed unsupported structural part of claim 2, wherein the number of the transition layers is 2-3, the transition layer closest to the cantilever edge of the suspended structure is a first transition layer, and the transition layer far from the cantilever edge of the suspended structure is a second transition layer and a third transition layer in sequence when the overhang angle is less than 30 degrees and is less than 20 degrees; the thickness of the first transition layer is 0.5-1.0 mm, the thickness of the second transition layer is set to be 1.0-1.5 mm, and the thickness of the third transition layer is set to be 1.0-1.5 mm.
5. The metal 3D printed unsupported structural part of claim 2, wherein the number of transition layers is set to 4-5 when the overhang angle is less than 20 ° and less than 10 °; the thickness of the first transition layer is 0.5-1.0 mm, the thickness of the second transition layer is set to 0.5-1.0 mm, the thickness of the third transition layer is set to 1.0-1.5 mm, the thickness of the fourth transition layer is set to 1.0-1.5 mm, and the thickness of the fifth transition layer is set to 1.0-1.5 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210070184.3A CN114769615B (en) | 2022-01-21 | 2022-01-21 | Metal 3D printing method without supporting structure |
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|---|---|---|---|
| CN202210070184.3A CN114769615B (en) | 2022-01-21 | 2022-01-21 | Metal 3D printing method without supporting structure |
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| CN114769615A CN114769615A (en) | 2022-07-22 |
| CN114769615B true CN114769615B (en) | 2024-01-30 |
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-
2022
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Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109420761A (en) * | 2017-08-28 | 2019-03-05 | 深圳市银宝山新科技股份有限公司 | The 3D printing method of hanging structure metalwork |
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| CN114769615A (en) | 2022-07-22 |
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