Numerical simulation method for microstructure evolution of magnesium alloy selective laser melting

A technology of laser selective melting and microstructure, which is applied in the field of additive manufacturing, can solve problems such as the inability to dynamically describe the microstructure evolution process, and achieve the effects of shortening the research and development cycle, improving quality, and reducing production costs

Inactive Publication Date: 2021-12-17
XI'AN UNIVERSITY OF ARCHITECTURE AND TECHNOLOGY
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  • Application Information

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Problems solved by technology

[0005] In view of the deficiencies in the existing technology, the purpose of the present invention is to provide a numerical simulation method for the microstructure evolution of magnesium alloy laser selective melting, so as to solve the problem that the characterization method in the prior art cannot dynamically describe the microstructure evolution process question

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  • Numerical simulation method for microstructure evolution of magnesium alloy selective laser melting
  • Numerical simulation method for microstructure evolution of magnesium alloy selective laser melting
  • Numerical simulation method for microstructure evolution of magnesium alloy selective laser melting

Examples

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Embodiment 1

[0056] This embodiment provides a numerical simulation method for microstructure evolution of magnesium alloy laser selective melting, specifically, this embodiment is an equiaxed crystal growth simulation under the SLM process.

[0057] Such as Figure 9 As shown, the method specifically includes the following steps:

[0058] Step 1, establish a macroscopic geometric model in the modeling software, divide the unit grid, set the boundary conditions, and determine the physical parameters of the material;

[0059] Step 1 is specifically implemented in the following steps:

[0060] Firstly, a three-dimensional model is established with a geometric size of 800 μm × 200 μm × 200 μm. The model is a regular cuboid, and the model grid is divided into structural quadrilateral grids with a grid size of 4 μm. Under this condition, after dividing the grid The number of meshes in the model is 500,000, and the number of nodes is 914,751; the initialization of the phase interface is realiz...

Embodiment 2

[0202] This embodiment provides a numerical simulation method for the microstructure evolution of magnesium alloy laser selective melting. Specifically, this embodiment is a simulation of the growth from planar to cellular and then to columnar crystals under the SLM process.

[0203] The method specifically includes the following steps:

[0204] Steps 1 to 4 and steps 6 to 8 in this embodiment are correspondingly the same as steps 1 to 4 and steps 6 to 8 in Embodiment 1, and the only difference is that step 5 is different.

[0205] In the present embodiment, step 5 is implemented according to the following steps:

[0206] In step 5.2, the establishment process of the nucleation model of columnar crystals grown epitaxially at the edge of the molten pool is as follows: for the nucleation of columnar crystals grown epitaxially on the base material grains, the nucleation model of columnar crystals grown epitaxially at the edge of the molten pool is as follows:

[0207]When the su...

Embodiment 3

[0211] This example provides a numerical simulation method for the microstructure evolution of magnesium alloy laser selective melting. Specifically, this example is a dendrite growth simulation of the transition from columnar crystals to equiaxed crystals under the SLM process.

[0212] The method specifically includes the following steps:

[0213] Steps 1 to 4 and steps 6 to 8 in this embodiment are correspondingly the same as steps 1 to 4 and steps 6 to 8 in Embodiment 1, and the only difference is that step 5 is different.

[0214] In step 5, the area corresponding to the microscopically calculated temperature field obtained in step 4 is the microscopically calculated area. For the microscopically calculated area, the equiaxed crystal nucleation model in the molten powder and the columnar crystal grown epitaxially at the edge of the molten pool are respectively established. nucleation model;

[0215] Specifically, step 5 is implemented in the following steps:

[0216] St...

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Abstract

The invention provides a numerical simulation method for microstructure evolution of magnesium alloy selective laser melting, which comprises the following steps of: simulating laser scanning by adopting a Gaussian surface heat source model; obtaining a flow field and a temperature field of a selective laser melting pool; applying a VOF method to track a free interface; selecting a specific two-dimensional section in a macroscopic geometric model to perform microstructure simulation calculation; respectively establishing an equiaxed crystal nucleation model in the molten powder and a nucleation model of columnar crystals epitaxially grown on the edge of the melting pool; respectively establishing a solid-phase solute diffusion model and a liquid-phase solute diffusion model; determining a growth kinetic model of dendritic crystals, and performing iterative calculation according to a cellular capture rule; and storing the data obtained by calculation, and carrying out visualization processing. The method can accurately and quantitatively predict the microstructure evolution process of the magnesium alloy in the selective laser melting process.

Description

technical field [0001] The invention belongs to the technical field of additive manufacturing and relates to magnesium alloys, in particular to a numerical simulation method for microstructure evolution of magnesium alloy laser selective melting. Background technique [0002] In addition to the inherent characteristics of pure magnesium with light weight and high specific strength, magnesium alloys also have excellent creep resistance and high temperature resistance, and are widely used in aerospace, transportation, machinery manufacturing, and communication electronics. However, defects such as porosity and shrinkage cavity caused by traditional die casting methods restrict the further improvement of the performance of magnesium alloys. [0003] Selective laser melting (SLM) is an additive manufacturing technology that directly manufactures parts. It can not only process complex shapes that are difficult to achieve by traditional casting, but also prepare high-density forme...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F30/28G06F30/23G06T3/40G06F111/10G06F113/08G06F119/08G06F119/14
CPCG06F30/28G06F30/23G06T3/4007G06F2119/08G06F2111/10G06F2113/08G06F2119/14
Inventor 王文礼刘文强徐蓉蓉戴秋昀
Owner XI'AN UNIVERSITY OF ARCHITECTURE AND TECHNOLOGY
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