Method of additive manufacturing of regular non-uniform porous structures

Abstract

The application provides an additive manufacturing method of regular non-uniform porous structure, comprising: (1) establishing a 3D solid model of a target part; (2) dividing different regions of the 3D solid model of the target part according to different characteristic parameters of the porous structure; (3) customizing corresponding additive manufacturing process parameters for the characteristic parameters of different regions of the 3D solid model of the target part; (4) segmenting the solid 3D model of the target part into several independent sub-models according to the boundaries of different regions in step (2); (5) assigning the additive manufacturing process parameters of different regions obtained in step (3) to the corresponding sub-models in step (4); (6) performing process planning and slicing; (7) performing additive manufacturing of the target part. The application has the advantages that: the porous structure does not need to be three-dimensionally modeled, the regular non-uniform porous structure can be formed at one time, the forming quality is high, and there is no distortion problem.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of additive manufacturing, and relates to an additive manufacturing method of regular non-uniform porous structure. BACKGROUND

[0002] The porous structure has the characteristics of low relative density, high specific strength, large specific surface area, wave resistance, heat insulation, permeability, etc., and has a wide range of application scenarios. For example, the porous structure has great weight reduction advantage in the fields of aerospace and aviation due to its high specific strength; the porous structure can be used as sound insulation material, vibration reduction material and anti-explosion impact material due to its wave resistance; the porous structure is used for preparing separation filter membrane due to its permeability.

[0003] However, for some parts, not only do they have porous structures, but their performance can be significantly improved when the pores are regularly and non-uniformly distributed. For example, the porous structure can be used as the surface layer of the pressure hull of an underwater vehicle. Studies have shown that when the part near the outer wall is a porous structure and the part near the inner wall is a solid structure, the underwater vehicle can not only withstand underwater pressure, but also effectively change the fluid characteristics of the surface layer of the vehicle and reduce the sailing resistance under certain working conditions, which is conducive to improving the endurance. For example, the heat pipe or heat plate components widely used in the fields of aerospace, new energy vehicles, electronic devices, superconductivity, etc. have solid outer walls and large specific surface area capillary porous structures attached to the inner walls, which make them have good heat dissipation characteristics.

[0004] Traditional porous structure preparation methods include foam metal method, powder metallurgy method, template method, etc., but the above methods cannot well control the shape, size and uniformity of the pores, and cannot prepare regular non-uniform porous structures. The popular additive manufacturing method in recent years can be used to prepare porous structures and accurately control the size and size of the pores, so that the porous structure can be customized as needed, but a three-dimensional model of the complex porous structure needs to be established, and when the pore structure is complex, problems such as structure collapse and change of pore characteristic parameters are likely to occur, resulting in distortion of the prepared porous structure. In addition, due to the existence of a limit minimum value of the beam spot size of the additive manufacturing equipment, when the minimum feature size of the three-dimensional geometric model is smaller than the limit minimum value of the beam spot, the prepared porous structure will also be distorted. Therefore, it is urgent to develop a preparation process of regular non-uniform porous structure which can be accurately controlled and accurately shaped. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides an additive manufacturing method of regular non-uniform porous structure, which does not need to establish a three-dimensional model of the porous structure, can shape the regular non-uniform porous structure at one time, has high shaping quality, and does not have the problem of distortion.

[0006] The application provides an additive manufacturing method of regular non-uniform porous structure, comprising the following specific steps:

[0007] (1) establishing a 3D solid model of a target part;

[0008] (2) dividing different regions of the 3D solid model of the target part according to different characteristic parameters of the porous structure;

[0009] (3) customizing corresponding additive manufacturing process parameters for the characteristic parameters of different regions of the 3D solid model of the target part;

[0010] (4) segmenting the solid 3D model of the target part into several independent sub-models according to the boundaries of different regions in step (2).

[0011] (5) assigning the additive manufacturing process parameters of different regions obtained in step (3) to the corresponding sub-models in step (4).

[0012] (6) process planning and slicing;

[0013] (7) additive manufacturing of the target part.

[0014] Further, the method for dividing different regions in step (2) is: using simulation software to perform numerical simulation of physical fields on the 3D solid model of the target part, mapping the field variable cloud diagram obtained by simulation onto the 3D solid model of the target part, and dividing different regions according to the isosurface of the field variable cloud diagram.

[0015] Further, the physical field includes one or more of stress field, strain field, flow field and acoustic field.

[0016] Further, the specific method of step (3) is:

[0017] ① determining the value range P min ~P max of the energy beam power P and the value range v min ~v max of the scanning speed v;

[0018] ② respectively designing and implementing the response surface test of the energy beam power P and the scanning speed v on any two pore characteristic parameters of porosity φ, pore diameter D, specific surface area S, hardness H and permeability K, and respectively fitting the linear regression model of the above two pore characteristic parameters on P and v;

[0019] ③ constructing an equation group and solving P and v according to the above two pore characteristic parameters required by the target part.

[0020] Another further scheme, the specific method of step (3) is:

[0021] ①determining the value range P of the energy beam power P min ~P max , the value range v of the scanning speed v min ~v max , the value range h of the filling interval h min ~h max ;

[0022] ②designing and implementing the response surface test of the energy beam power P, the scanning speed v and the filling interval h on any three of the porosity φ, the pore size D, the specific surface area S, the hardness H and the permeability K respectively, and fitting the linear regression model of the above three porosity parameters about P, v and h respectively;

[0023] ③constructing the equation group, and solving P, v and h according to the above three porosity parameters required by the target part.

[0024] Another further scheme, the specific method of step (3) is:

[0025] ①determining the value range P of the energy beam power P min ~P max , the value range v of the scanning speed v min ~v max , the value range F of the energy beam defocusing amount F min ~F max ;

[0026] ②designing and implementing the response surface test of the energy beam power P, the scanning speed v and the energy beam defocusing amount F on any three of the porosity φ, the pore size D, the specific surface area S, the hardness H and the permeability K respectively, and fitting the linear regression model of the above three porosity parameters about P, v and F respectively;

[0027] ③constructing the equation group, and solving P, v and F according to the above three porosity parameters required by the target part.

[0028] Another further scheme, the specific method of step (3) is:

[0029] ①determining the value range P of the energy beam power P min ~P max , the value range v of the scanning speed v min ~v max , the value range h of the filling interval h min ~h max , and the value range F of the energy beam defocusing amount F min ~F max ;

[0030] ②Design and implement the response surface test of energy beam power P, scanning speed v, filling interval h and energy beam defocusing amount F about any four pore characteristic parameters of porosity φ, pore size D, specific surface area S, hardness H, permeability K respectively, and linear regression models of the above four pore characteristic parameters about P, v, h, F are fitted respectively;

[0031] ③Construct an equation group, and solve P, v, h, F according to the above four pore characteristic parameters required by the target part.

[0032] The beneficial effects of the present application are:

[0033] By adjusting one or more of the energy beam power P, the scanning speed v, the filling interval h and the energy beam defocusing amount F, the present application can not only adjust the gap between adjacent deposition paths, but also adjust the stability of the molten pool, so that small pores are generated inside the deposition path, and the minimum feature size of the porous structure prepared can be much smaller than the lower limit value of the equipment resolution.

[0034] The present application can form a regular non-uniform porous structure at one time, has high forming quality, and does not have the problems of collapse, change of pore structure and distortion caused by low equipment resolution in traditional additive manufacturing processes, and does not need to model the large number of complex lattice type porous structures inside the part, but only needs to model the geometric shape of the part, greatly simplifying the modeling complexity, improving the modeling efficiency, and reducing the influence of the three-dimensional geometric model on the quality of the formed part. DETAILED DESCRIPTION

[0035] The specific implementation of the present application is further described below in conjunction with examples, but the implementation and protection of the present application are not limited thereto. It should be noted that if the following processes are not specifically described in detail, they can be implemented or understood by referring to the prior art.

[0036] Example 1

[0037] The present application provides an additive manufacturing method of a regular non-uniform porous structure, comprising the following specific steps:

[0038] (1) Establish a 3D solid model of the target part;

[0039] (2) According to different characteristic parameters of the porous structure, the 3D solid model of the target part is divided into different regions; the method of dividing different regions is: using simulation software to perform numerical simulation of physical field on the 3D solid model of the target part, mapping the field variable cloud map obtained by simulation to the 3D solid model of the target part, and dividing different regions according to the isosurface of the field variable cloud map; the physical field includes one or more of stress field, strain field, flow field and sound field;

[0040] (3) Customizing the corresponding additive manufacturing process parameters for the characteristic parameters of different regions of the 3D solid model of the target part; the specific method is:

[0041] ① Determine the value range of the energy beam power P min ~ P max , the value range of the scanning speed v min ~ v max ;

[0042] ② Design and implement the response surface test of the energy beam power P and the scanning speed v with respect to any two of the porosity φ, the pore size D, the specific surface area S, the hardness H, and the permeability K, respectively, and fit the linear regression model of the above two porosity characteristic parameters with respect to P and v;

[0043] ③ Construct an equation group, and solve P and v according to the above two porosity characteristic parameters required by the target part;

[0044] (4) According to the division surface of different regions in step (2), the solid 3D model of the target part is divided into several independent sub-models.

[0045] (5) Assign the additive manufacturing process parameters of different regions obtained in step (3) to the corresponding sub-models in step (4).

[0046] (6) Process planning and slicing;

[0047] (7) Additive manufacturing of the target part.

[0048] Example 2

[0049] The present application provides an additive manufacturing method of regular non-uniform porous structure, compared with example 1, only the specific method of step (3) is different from example 1, which is:

[0050] ① Determine the value range of the energy beam power P min ~ P max , the value range of the scanning speed v min ~ v max , and the value range of the filling interval h min ~ h max ;

[0051] ② Design and implement the response surface test of the energy beam power P, the scanning speed v, and the filling interval h with respect to any three of the porosity φ, the pore size D, the specific surface area S, the hardness H, and the permeability K, respectively, and fit the linear regression model of the above three porosity characteristic parameters with respect to P, v, and h;

[0052] ③ Constructing equation group, according to the above three porosity characteristic parameters required by the target part, P, v and h are solved.

[0053] Example 3

[0054] The application provides a regular non-uniform porous structure additive manufacturing method, compared with example 1, only the specific method of step (3) is different from example 1, specifically:

[0055] ① Determine the value range P of the energy beam power P min ~ P max , the value range v of the scanning speed v min ~ v max , the value range F of the energy beam defocusing amount F min ~ F max ;

[0056] ② Respectively design and implement the response surface test of the energy beam power P, the scanning speed v and the energy beam defocusing amount F on any three porosity characteristic parameters of porosity φ, pore size D, specific surface area S, hardness H and permeability K, and linear regression models of the above three porosity characteristic parameters on P, v and F are fitted respectively;

[0057] ③ Constructing equation group, according to the above three porosity characteristic parameters required by the target part, P, v and F are solved.

[0058] Example 4

[0059] The application provides a regular non-uniform porous structure additive manufacturing method, compared with example 1, only the specific method of step (3) is different from example 1, specifically:

[0060] ① Determine the value range P of the energy beam power P min ~ P max , the value range v of the scanning speed v min ~ v max , the value range h of the filling interval h min ~ h max , and the value range F of the energy beam defocusing amount F min ~ F max ;

[0061] ② Respectively design and implement the response surface test of the energy beam power P, the scanning speed v, the filling interval h and the energy beam defocusing amount F on any four porosity characteristic parameters of porosity φ, pore size D, specific surface area S, hardness H and permeability K, and linear regression models of the above four porosity characteristic parameters on P, v, h and F are fitted respectively;

[0062] ③ Constructing equation group, according to the above four porosity characteristic parameters required by the target part, P, v, h and F are solved.

[0063] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the application.

Claims

1. An additive manufacturing method for a regularly non-uniform porous structure, characterized in that: Includes the following steps: (1) Establish a 3D solid model of the target part; (2) According to the different characteristic parameters of the porous structure, the 3D solid model of the target part is divided into different regions: the physical field is simulated by the simulation software, the field variable cloud map obtained by simulation is mapped onto the 3D solid model of the target part, and different regions are divided according to the isosurface of the field variable cloud map; the physical field includes one or more of stress field, strain field, flow field and sound field; (3) Customize the corresponding additive manufacturing process parameters for the characteristic parameters of different regions of the 3D solid model of the target part. The specific method is as follows: ① Determine the range of values ​​for the energy beam power P. min ~P max and the range of values ​​for the scanning speed v min ~v max ; ② Design and implement response surface experiments of energy beam power P and scanning speed v with respect to any two of the porosity parameters φ, pore size D, specific surface area S, hardness H, and permeability K, and fit linear regression models of the above two porosity parameters with respect to P and v respectively. ③ Construct a system of equations and solve for P and v based on the two porosity characteristic parameters required for the target part. (4) Based on the interfaces of different regions in step (2), divide the solid 3D model of the target part into several independent sub-models; (5) Assign the additive manufacturing process parameters of different regions obtained in step (3) to the corresponding sub-models in step (4); (6) Conduct process planning and slicing; (7) Perform additive manufacturing of the target part.

2. The additive manufacturing method for regular non-uniform porous structures according to claim 1, characterized in that: The specific method of step (3) is replaced as follows: ① Determine the range of values ​​for the energy beam power P. min ~P max The range of values ​​for the scanning speed v min ~v max The range of values ​​for the fill spacing h min ~h max ; ② Design and implement response surface experiments for energy beam power P, scanning speed v, and filling spacing h with respect to any three pore characteristic parameters among porosity φ, pore size D, specific surface area S, hardness H, and permeability K, and fit linear regression models of the above three pore characteristic parameters with respect to P, v, and h respectively. ③ Construct a system of equations and solve for P, v, and h based on the three porosity characteristic parameters required for the target part.

3. The additive manufacturing method for regular non-uniform porous structures according to claim 1, characterized in that: The specific method of step (3) is replaced as follows: ① Determine the range of values ​​for the energy beam power P. min ~P max The range of values ​​for the scanning speed v min ~v max The range of values ​​for the energy beam defocusing amount F min ~F max ; ② Design and implement response surface experiments of energy beam power P, scanning speed v and energy beam defocusing amount F with respect to any three pore characteristic parameters among porosity φ, pore size D, specific surface area S, hardness H and permeability K, and fit linear regression models of the above three pore characteristic parameters with respect to P, v and F respectively. ③ Construct a system of equations and solve for P, v, and F based on the three porosity characteristic parameters required for the target part.

4. The additive manufacturing method for regular non-uniform porous structures according to claim 1, characterized in that: The specific method of step (3) is replaced as follows: ① Determine the range of values ​​for the energy beam power P. min ~P max The range of values ​​for the scanning speed v min ~v max The range of values ​​for the fill spacing h min ~h max And the range of values ​​for the energy beam defocusing amount F. min ~F max ; ② Design and implement response surface experiments for energy beam power P, scanning speed v, filling spacing h, and energy beam defocusing amount F with respect to any four pore characteristic parameters among porosity φ, pore size D, specific surface area S, hardness H, and permeability K, and fit linear regression models of the above four pore characteristic parameters with respect to P, v, h, and F respectively. ③ Construct a system of equations and solve for P, v, h, and F based on the four porosity characteristic parameters required for the target part.