Selective laser melting process printing parameter optimization method and system

Abstract

The invention discloses a method and a system for optimizing printing parameters of a selective laser melting process. The method comprises the following steps: establishing a geometric model of a target formed part; setting material attributes and boundary conditions, and establishing a three-dimensional finite element model according to the three-dimensional model, the material attributes and the boundary conditions; setting printing parameters; performing thermal analysis on the three-dimensional finite element model according to the printing parameters to obtain a thermal analysis result; performing stress deformation analysis on the three-dimensional finite element model according to a thermal analysis result to obtain a stress deformation distribution result; judging whether the stress deformation distribution result meets a preset condition or not according to the stress deformation distribution result and the preset condition; if yes, the printing parameters corresponding to the stress deformation distribution result meeting the preset condition serve as target printing parameters of the target formed part; and if not, the printing parameters are adjusted until the stress deformation distribution result meets the preset condition. The forming precision of the finally printed target forming part is improved, the operation process is simple, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a method and system for optimizing printing parameters of a selective laser melting process. Background Art

[0002] As an advanced metal additive manufacturing method, Selective Laser Melting (SLM) technology has attracted widespread attention because it can directly manufacture complex geometries and high-performance materials. SLM technology melts and solidifies metal powder layer by layer, and can quickly produce highly customized parts without the need for traditional molds.

[0003] However, the precision of metal parts formed by SLM technology is easily affected by many factors, such as printing parameters and material properties. In the prior art, parts with different printing parameters are often printed and then analyzed, which is cumbersome and easy to cause waste and high cost. Summary of the invention

[0004] In order to solve the technical problems existing in the background technology, the present invention proposes a method and system for optimizing printing parameters of a selective laser melting process.

[0005] In a first aspect, the present invention provides a method for optimizing printing parameters of a selective laser melting process, comprising:

[0006] Establish the geometric model of the target molded part;

[0007] Set material properties and boundary conditions, and build a three-dimensional finite element model based on the three-dimensional model, material properties and boundary conditions;

[0008] Set printing parameters;

[0009] According to the printing parameters, the three-dimensional finite element model is thermally analyzed to obtain the thermal analysis results;

[0010] According to the thermal analysis results, the stress-deformation analysis is performed on the three-dimensional finite element model to obtain the stress-deformation distribution results;

[0011] According to the stress-strain distribution results and preset conditions, judging whether the stress-strain distribution results meet the preset conditions;

[0012] If so, the printing parameters corresponding to the stress-strain distribution results meeting the preset conditions are used as the target printing parameters of the target molded part;

[0013] If not, adjust the printing parameters until the stress-deformation distribution results meet the preset conditions.

[0014] Preferably, the thermal analysis results include a temperature distribution diagram, and the stress-deformation distribution results include an equivalent stress distribution cloud diagram and a deformation distribution cloud diagram.

[0015] Preferably, the printing parameters include laser power, scanning speed, layer thickness, laser spot diameter, scanning spacing and inter-layer dwell time.

[0016] Preferably, the material properties include Young's modulus, Poisson's ratio, thermal conductivity, specific heat capacity, density, yield strength, thermal expansion coefficient and dielectric constant.

[0017] Preferably, the boundary conditions include displacement boundary conditions, convection / radiation boundary conditions and symmetry boundary conditions.

[0018] In a second aspect, the present invention further proposes a system for optimizing printing parameters of a selective laser melting process, comprising:

[0019] A first model building module is used to build a geometric model of a target molded part;

[0020] The second model building module is used to set material properties and boundary conditions, and build a three-dimensional finite element model based on the three-dimensional model, material properties and boundary conditions;

[0021] Optimization module, used to set printing parameters;

[0022] According to the printing parameters, the three-dimensional finite element model is thermally analyzed to obtain the thermal analysis results;

[0023] According to the thermal analysis results, the stress-deformation analysis is performed on the three-dimensional finite element model to obtain the stress-deformation distribution results;

[0024] According to the stress-strain distribution results and preset conditions, judging whether the stress-strain distribution results meet the preset conditions;

[0025] If so, the printing parameters corresponding to the stress-strain distribution results meeting the preset conditions are used as the target printing parameters of the target molded part;

[0026] If not, adjust the printing parameters until the stress-deformation distribution results meet the preset conditions.

[0027] Preferably, the thermal analysis results include a temperature distribution diagram, and the stress-deformation distribution results include an equivalent stress distribution cloud diagram and a deformation distribution cloud diagram.

[0028] Preferably, the printing parameters include laser power, scanning speed, layer thickness, laser spot diameter, scanning spacing and inter-layer dwell time.

[0029] Preferably, the material properties include Young's modulus, Poisson's ratio, thermal conductivity, specific heat capacity, density, yield strength, thermal expansion coefficient and dielectric constant.

[0030] Preferably, the boundary conditions include displacement boundary conditions, convection / radiation boundary conditions and symmetry boundary conditions.

[0031] In the present invention, the proposed method and system for optimizing the printing parameters of the selective laser melting process simulates and thermodynamically analyzes the target molded part through the finite element method, and can optimize the printing parameters whose stress and deformation distribution results meet the preset conditions, thereby improving the molding accuracy of the target molded part finally printed, with a simple operation process and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic flow chart of a method for optimizing printing parameters of a selective laser melting process in one embodiment of the present invention.

[0033] Figure 2 It is a schematic structural diagram of a geometric model of a target molded part in an embodiment of the present invention.

[0034] Figure 3 Schematic diagram of boundary conditions in an embodiment of the present invention; wherein (a) represents displacement boundary conditions, (b) represents convection / radiation conditions, and (c) represents symmetry boundary conditions.

[0035] Figure 4 FIG. 1 is a schematic diagram of thermal analysis results according to an embodiment of the present invention.

[0036] Figure 5 It is a schematic diagram of stress-strain distribution results in one embodiment of the present invention. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] Reference Figure 1 The present invention proposes a method for optimizing printing parameters of a selective laser melting process, comprising:

[0039] Establish the geometric model of the target molded part;

[0040] Set material properties and boundary conditions, and build a three-dimensional finite element model based on the three-dimensional model, material properties and boundary conditions;

[0041] Set printing parameters;

[0042] According to the printing parameters, the three-dimensional finite element model is thermally analyzed to obtain the thermal analysis results;

[0043] According to the thermal analysis results, the stress-deformation analysis is performed on the three-dimensional finite element model to obtain the stress-deformation distribution results;

[0044] According to the stress-strain distribution results and preset conditions, judging whether the stress-strain distribution results meet the preset conditions;

[0045] If so, the printing parameters corresponding to the stress-strain distribution results meeting the preset conditions are used as the target printing parameters of the target molded part;

[0046] If not, adjust the printing parameters until the stress-deformation distribution results meet the preset conditions.

[0047] The present invention performs simulation and analysis through the finite element method, and can optimize the printing parameters whose stress deformation distribution results meet the preset conditions, thereby improving the molding accuracy of the target molded parts finally printed, and the operation process is simple and the cost is low.

[0048] In this embodiment, the preset condition is that the deformation amount meets the preset deformation amount.

[0049] It should be understood that thermal analysis is a transient thermal analysis that uses the temperature field distribution cloud diagram to determine the uneven thermal expansion caused by temperature differences.

[0050] In this embodiment, the thermal analysis results include a temperature distribution map.

[0051] This embodiment can identify potential heat concentration areas according to the temperature distribution map.

[0052] In this embodiment, the stress-deformation distribution results include: an equivalent stress distribution cloud diagram and a deformation distribution cloud diagram.

[0053] With such a setting, the deformation condition of each area can be judged by checking the stress release condition and the deformation amount according to the equivalent stress distribution cloud map and the deformation distribution cloud map, without having to print out the target molded part before making a judgment.

[0054] In this embodiment, the printing parameters include laser power, scanning speed, layer thickness, laser spot diameter, scanning spacing and inter-layer dwell time.

[0055] In this embodiment, the three-dimensional modeling software is Solidworks software, UG software or PRO-E software.

[0056] In this embodiment, the material properties include Young's modulus, Poisson's ratio, thermal conductivity, specific heat capacity, density, yield strength, thermal expansion coefficient, and dielectric constant.

[0057] In this embodiment, the boundary conditions include displacement boundary conditions, convection / radiation boundary conditions and symmetry boundary conditions.

[0058] The present invention also proposes a system for optimizing printing parameters of a selective laser melting process, comprising:

[0059] A first model building module is used to build a geometric model of a target molded part;

[0060] The second model building module is used to set material properties and boundary conditions, and build a three-dimensional finite element model based on the three-dimensional model, material properties and boundary conditions;

[0061] Optimization module, used to set printing parameters;

[0062] According to the printing parameters, the three-dimensional finite element model is thermally analyzed to obtain the thermal analysis results;

[0063] According to the thermal analysis results, the stress-deformation analysis is performed on the three-dimensional finite element model to obtain the stress-deformation distribution results;

[0064] According to the stress-strain distribution results and preset conditions, judging whether the stress-strain distribution results meet the preset conditions;

[0065] If so, the printing parameters corresponding to the stress-strain distribution results meeting the preset conditions are used as the target printing parameters of the target molded part;

[0066] If not, adjust the printing parameters until the stress-deformation distribution results meet the preset conditions.

[0067] The present invention uses the finite element method to perform thermodynamic simulation and analysis on the target molded part, and can optimize the printing parameters whose stress and deformation distribution results meet the preset conditions, thereby improving the molding accuracy of the target molded part finally printed. The operation process is simple and the cost is low, and it has a good application prospect in the field of additive manufacturing.

[0068] In this embodiment, the thermal analysis results include a temperature distribution diagram, and the stress-deformation distribution results include an equivalent stress distribution cloud diagram and a deformation distribution cloud diagram.

[0069] In this embodiment, the printing parameters include laser power, scanning speed, layer thickness, laser spot diameter, scanning spacing and inter-layer dwell time.

[0070] In this embodiment, the material properties include Young's modulus, Poisson's ratio, thermal conductivity, specific heat capacity, density, yield strength, thermal expansion coefficient, and dielectric constant.

[0071] In this embodiment, the boundary conditions include displacement boundary conditions, convection / radiation boundary conditions and symmetry boundary conditions.

[0072] The present invention will be described below with reference to specific embodiments.

[0073] Example 1

[0074] The present embodiment provides a method for optimizing printing parameters of a selective laser melting process, including:

[0075] Establish the geometric model of the target molded part; the geometric model is a cuboid with a length of 80 mm, a width of 40 mm, and a thickness of 5 mm, such as Figure 2 As shown;

[0076] Set material properties and boundary conditions, and establish a three-dimensional finite element model based on the three-dimensional model, material properties and boundary conditions; the material used in the three-dimensional finite element model is AlSi10Mg, and the material properties include: Young's modulus is 70GPa, Poisson's ratio is 0.33, thermal conductivity is 150W / mK, specific heat capacity is 900J / kg·K, density is 2.65g / cm, yield strength is 250MPa, thermal expansion coefficient is 22×10-6 / K, and dielectric constant is 8.5; the displacement boundary condition is the bottom surface of the substrate, such as Figure 3 As shown in (a) of , the convection / radiation boundary condition is the side of the cuboid, such as Figure 3 As shown in (b) in the figure, the symmetry boundary conditions are the two sides of the cuboid, such as Figure 3 As shown in (c);

[0077] Set the printing parameters; the printing parameters include: laser power 850W, scanning speed 1200m / s, layer thickness 0.04μm, laser spot diameter 0.1mm, scanning interval 0.1mm, and interlayer dwell time 10s;

[0078] According to the printing parameters, the three-dimensional finite element model is thermally analyzed to obtain the thermal analysis results; among them, the thermal analysis results are as follows: Figure 4 As shown;

[0079] According to the thermal analysis results, the stress-deformation analysis is performed on the three-dimensional finite element model to obtain the stress-deformation distribution results. Figure 5 As shown;

[0080] According to the stress-strain distribution results and preset conditions, judging whether the stress-strain distribution results meet the preset conditions;

[0081] according to Figure 5 It can be seen that the maximum deformation of this embodiment is 0.25 mm, which meets the preset conditions;

[0082] Therefore, the printing parameters in this embodiment are used as the target printing parameters of the target molded part.

[0083] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for optimizing printing parameters of a selective laser melting process, characterized in that: include: Establish the geometric model of the target molded part; Set material properties and boundary conditions, and build a three-dimensional finite element model based on the three-dimensional model, material properties and boundary conditions; Setting printing parameters, and performing thermal analysis on the three-dimensional finite element model according to the printing parameters to obtain thermal analysis results; According to the thermal analysis results, the stress-deformation analysis is performed on the three-dimensional finite element model to obtain the stress-deformation distribution results; According to the stress-strain distribution results and preset conditions, judging whether the stress-strain distribution results meet the preset conditions; If so, the printing parameters corresponding to the stress-strain distribution results meeting the preset conditions are used as the target printing parameters of the target molded part; If not, adjust the printing parameters until the stress-deformation distribution results meet the preset conditions.

2. The method for optimizing printing parameters of a selective laser melting process according to claim 1, characterized in that: The thermal analysis results include temperature distribution diagrams, and the stress-deformation distribution results include equivalent stress distribution cloud diagrams and deformation distribution cloud diagrams.

3. The method for optimizing printing parameters of a selective laser melting process according to claim 1, characterized in that: Printing parameters include laser power, scanning speed, layer thickness, laser spot diameter, scanning spacing, and inter-layer dwell time.

4. The method for optimizing printing parameters of a selective laser melting process according to claim 1, characterized in that: Material properties include Young's modulus, Poisson's ratio, thermal conductivity, specific heat, density, yield strength, coefficient of thermal expansion, and dielectric constant.

5. The method for optimizing printing parameters of a selective laser melting process according to claim 1, characterized in that: Boundary conditions include displacement boundary conditions, convection / radiation boundary conditions and symmetry boundary conditions.

6. A system for optimizing printing parameters of a selective laser melting process, characterized in that: include: A first model building module is used to build a geometric model of a target molded part; The second model building module is used to set material properties and boundary conditions, and build a three-dimensional finite element model based on the three-dimensional model, material properties and boundary conditions; Optimization module, used to set printing parameters; According to the printing parameters, the three-dimensional finite element model is thermally analyzed to obtain the thermal analysis results; According to the thermal analysis results, the stress-deformation analysis is performed on the three-dimensional finite element model to obtain the stress-deformation distribution results; According to the stress-strain distribution results and preset conditions, judging whether the stress-strain distribution results meet the preset conditions; If so, the printing parameters corresponding to the stress-strain distribution results meeting the preset conditions are used as the target printing parameters of the target molded part; If not, adjust the printing parameters until the stress-deformation distribution results meet the preset conditions.

7. The system for optimizing printing parameters of a selective laser melting process according to claim 6, characterized in that: The thermal analysis results include temperature distribution diagrams, and the stress-deformation distribution results include equivalent stress distribution cloud diagrams and deformation distribution cloud diagrams.

8. The system for optimizing printing parameters of a selective laser melting process according to claim 6, characterized in that: Printing parameters include laser power, scanning speed, layer thickness, laser spot diameter, scanning spacing, and inter-layer dwell time.

9. The system for optimizing printing parameters of a selective laser melting process according to claim 6, characterized in that: Material properties include Young's modulus, Poisson's ratio, thermal conductivity, specific heat, density, yield strength, coefficient of thermal expansion, and dielectric constant.

10. The system for optimizing printing parameters of a selective laser melting process according to claim 1, characterized in that: Boundary conditions include displacement boundary conditions, convection / radiation boundary conditions and symmetry boundary conditions.

Images