Support form, printing parameters and forming method for 3D printing of high-temperature alloy bionic structure
Technical Field
The invention relates to the technical field of 3D printing, in particular to a support form, printing parameters and a forming method for 3D printing of a high-temperature alloy bionic structure.
Background
SLM (selective laser melting) is a major technical approach in the additive manufacturing of metallic materials. The technology selects laser as an energy source, scans a metal superalloy powder bed layer by layer according to a planned path in a three-dimensional CAD slicing model, and the scanned metal superalloy powder achieves the effect of metallurgical bonding through melting and solidification, so as to finally obtain a metal part designed by the model.
The core components of the aerospace engine are all in service under the high-temperature condition, the heat dissipation design of the components is particularly important, the designed high-efficiency heat dissipation self-growing type heat dissipation structure can be attached to a heat transfer path to conduct heat effectively, but the structure is complex and special, the size is fine, the local characteristic is only 0.1mm, the conventional manufacturing difficulty is high, the period is long, and 3D printing is undoubtedly the manufacturing method which is most suitable for forming the complex structure.
But the existing 3D printing technology can not realize the fine manufacturing of the structure, only the structural design can be changed, and the heat dissipation efficiency and the research and development index are reduced to cater to the existing 3D printing technology. Therefore, a support form, printing parameters and a forming method for 3D printing of the high-temperature alloy bionic structure are provided.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects of the prior art, the invention provides a support form, printing parameters and a forming method for 3D printing of a high-temperature alloy bionic structure, overcomes the defects of the prior art, is reasonable in design and compact in structure, and aims to solve the problem that the conventional 3D printing technology cannot realize the manufacture of a high-efficiency heat dissipation self-growing heat dissipation structure of an aerospace engine core component.
(II) technical scheme
In order to achieve the purpose, the invention is realized by the following technical scheme:
a forming method for 3D printing of a high-temperature alloy bionic structure comprises the following steps:
s1, determining the placing angle of the 3D printed part, and performing simulation by using simulation software according to the determined placing angle;
s2, determining a support adding part according to the simulation result, wherein the judgment of the support adding part is determined as that the part needs to be supported and added when the formula <1> is satisfied according to the judgment of the support adding part shown as the formula <1 >;
σs≥R <1>
in the formula: sigmas-Mise equivalent stress; in the R-3D printing process, the three-point bending strength of the material at the temperature is obtained;
s3, adding a support structure at the support adding part to form a printing model;
s4, slicing and subdividing by using the forming parameters, forming a printing program and importing the printing program into a 3D printer;
and S5, starting the 3D printer after high-temperature alloy powder is filled and the flexible scraper is installed, and spreading the powder by the printer for printing.
Preferably, in the step S4, the formed section has a thickness of 0.015 to 0.03 mm.
Preferably, in the step S5, the particle size of the superalloy powder raw material is 10 to 55 μm.
Preferably, in step S5, the flexible scraper is made of a wear-resistant plastic material.
The invention also provides a support form for 3D printing of the high-temperature alloy bionic structure, wherein the 3D printing support form is that a hollow rod-shaped support structure is used at the support adding part.
Preferably, the outer diameter phi of the hollow rod-shaped supporting structure is 0.6 mm-0.8 mm, and the wall thickness is 0.08 mm-0.11 mm.
Preferably, the support adding part is a stress concentration area obtained by simulation with simulation software.
The invention also provides printing parameters for the 3D printing forming method of the high-temperature alloy bionic structure, wherein the printing parameters comprise the printing parameters of the support structure and the printing parameters of the part body;
the support structure printing parameter indexes comprise: laser power, laser scanning speed, laser path, scanning strategy, scanning track interval and spot diameter;
the part body printing parameter indexes comprise: filling laser power, filling laser scanning speed, track spacing, outer ring number, scanning path, outer ring laser power, outer ring scanning speed and spot diameter.
Preferably, in the printing parameters of the supporting structure, the laser power is 80-120W, the laser scanning speed is 850-1100 mm/s, the laser path is spiral, the scanning strategy is one period of three layers each time, the middle layer is designed to be not scanned, the front layer and the rear layer are designed to be scanned in the period, the distance between laser scanning tracks is 0.04-0.06 mm, and the diameter of a light spot is 0.6-0.75 mm.
Preferably, in the printing parameters of the part body, the power of the filling laser is 130-160W, the scanning speed of the filling laser is 950-1200 mm/s, the track pitch is 0.1-0.13 mm, the diameter of a light spot is 0.6-0.75 mm, and the number of outer rings is 2;
the laser power of the outer ring of the first layer is 80-105W, and the laser scanning speed is 290-350 mm/s;
the laser power of the second outer ring is 70-85W, and the laser scanning speed of the outer ring is 900-1150 mm/s.
(III) advantageous effects
The embodiment of the invention provides a support form, printing parameters and a forming method for 3D printing of a high-temperature alloy bionic structure, which have the following beneficial effects:
1. the hollow rod-shaped support structure suitable for 3D printing is adopted, the strength is lower than that of the existing solid conical support structure, the support structure is easier to remove without damaging parts, and meanwhile, because the support structure is hollow, the support weight is reduced, and the consumption of printing raw materials is greatly reduced.
2. According to the invention, a stress concentration area is obtained through simulation of the forming process, the support adding position is reduced to the maximum extent, and the forming stability is improved.
3. The special 3D printing laser forming sintering parameters adopted by the invention enable the refined bionic structure to be manufactured by adopting a 3D printing technology.
Drawings
The above features, technical features, advantages and implementations of a support format, printing parameters and forming method for 3D printing of a superalloy biomimetic structure will be further described in the following description of preferred embodiments in a clearly understandable manner with reference to the accompanying drawings.
FIG. 1 is a flow chart of a 3D printing forming method of a high-temperature alloy bionic structure in the invention;
FIG. 2 is a schematic view of a hollow bar support structure according to the present invention;
FIG. 3 is a drawing of a part of the biomimetic structure of the present invention;
FIG. 4 is a three-dimensional simulation bottom view of the biomimetic structure in the present invention;
FIG. 5 is an additional view of the biomimetic structural support of the present invention.
Detailed Description
The invention will be further illustrated with reference to the following figures 1 to 5 and examples:
example 1
A forming method for 3D printing of a superalloy biomimetic structure, with reference to fig. 3-5, the forming method comprising the steps of:
s1, selecting a placing mode with the bottom facing downwards and the bionic structure facing upwards, and performing simulation by using simulation software according to the determined placing angle;
s2, determining a support adding part according to the simulation result, wherein the judgment of the support adding part is determined as that the part needs to be supported and added when the formula <1> is satisfied according to the judgment of the support adding part shown as the formula <1 >;
σs≥R <1>
in the formula: sigmas-Mise equivalent stress; in the R-3D printing process, the three-point bending strength of the material at the temperature is obtained;
s3, adding a hollow rod-shaped support structure at the support adding part to form a printing model;
s4, slicing and subdividing by using the forming parameters, forming a printing program and importing the printing program into a 3D printer;
s5, the 3D printer is started after high-temperature alloy powder is filled and the flexible scraper is installed, and the printer spreads the powder for printing;
referring to the three-dimensional simulation diagram of the bionic structure shown in fig. 3, the characteristic dimension is 0.1mm, referring to fig. 4 and 5, fig. 4 is a support adding part (light gray display part) determined according to a simulation result after simulation is performed by using simulation software, and fig. 5 is a three-dimensional diagram for supporting and adding a hollow rod-shaped support structure selected and designed.
In this embodiment, in the step S4, the thickness of the formed slice is 0.015 to 0.03 mm.
In this embodiment, in the step S5, the particle size of the superalloy powder raw material is 10 to 55 μm.
In this embodiment, in step S5, the flexible scraper is made of a wear-resistant plastic material.
Example 2
The invention also provides a support form for 3D printing of the high-temperature alloy bionic structure, wherein the 3D printing support form is that a hollow rod-shaped support structure is used at a support adding part, and as shown in figure 2, the hollow rod-shaped support structure is a strip-column-shaped structure with one conical end and hollow inside.
In this embodiment, as shown in fig. 2, the outer diameter Φ of the hollow rod-like support structure is 0.6mm to 0.8mm, and the wall thickness is 0.08mm to 0.11 mm.
In this embodiment, as shown in fig. 3 and 4, the support adding portion is a stress concentration region obtained by simulation using simulation software.
Other undescribed structures refer to example 1.
Example 3
The invention also provides printing parameters for the 3D printing forming method of the high-temperature alloy bionic structure, wherein the printing parameters comprise the printing parameters of the support structure and the printing parameters of the part body;
the support structure printing parameter indexes comprise: laser power, laser scanning speed, laser path, scanning strategy, scanning track interval and spot diameter;
the part body printing parameter indexes comprise: filling laser power, filling laser scanning speed, track spacing, outer ring number, scanning path, outer ring laser power, outer ring scanning speed and spot diameter.
In the embodiment, among the printing parameters of the supporting structure, the laser power is 80-120W, the laser scanning speed is 850-1100 mm/s, the laser path is spiral, the scanning strategy is one period of three layers each time, the middle layer is designed not to be scanned, and the front layer and the rear layer are designed to be scanned in the period, the laser scanning track interval is 0.04-0.06 mm, and the spot diameter is 0.6-0.75 mm.
In the embodiment, in the printing parameters of the part body, the power of the inner filling laser is 130-160W, the scanning speed of the inner filling laser is 950-1200 mm/s, the track pitch is 0.1-0.13 mm, the diameter of a light spot is 0.6-0.75 mm, and the number of outer rings is 2;
the laser power of the outer ring of the first layer is 80-105W, and the laser scanning speed is 290-350 mm/s;
the laser power of the second outer ring is 70-85W, and the laser scanning speed of the outer ring is 900-1150 mm/s.
Other undescribed structures refer to examples 1 and 2.
According to the supporting form, the printing parameters and the forming method for the 3D printing of the high-temperature alloy bionic structure, a hollow rod-shaped supporting structure suitable for the 3D printing is adopted, compared with the existing solid conical supporting structure, the strength is low, the removal is easier without damaging parts, and meanwhile, because the supporting structure is hollow, the supporting weight is reduced, and the consumption of printing raw materials is greatly reduced;
the existing 3D printing technology requires that the bottom of a structure with a forming angle smaller than 45 degrees needs to be additionally supported, but due to the complexity and the particularity of a bionic heat dissipation structure, if the support is additionally arranged at the bottom of an area with the forming angle smaller than 45 degrees, the supporting volume is large, and a refined structure fails to form; according to the method, a stress concentration area is obtained through simulation of a forming process, the number of support adding parts is reduced to the maximum extent, and forming stability is improved;
by combining the special 3D printing laser forming sintering parameters, the refined bionic structure can be manufactured by adopting a 3D printing technology, and powerful support is provided for the development of engines in the aerospace field.
The embodiments of the present invention are disclosed as the preferred embodiments, but not limited thereto, and those skilled in the art can easily understand the spirit of the present invention and make various extensions and changes without departing from the spirit of the present invention.