Three-Dimensional Modeling of Selective Laser Sintering of Two-Component Metal Powder Layers

2005 ◽  
Vol 128 (1) ◽  
pp. 299-306 ◽  
Author(s):  
Tiebing Chen ◽  
Yuwen Zhang

Laser sintering of a metal powder mixture that contains two kinds of metal powders with significantly different melting points under a moving Gaussian laser beam is investigated numerically. The continuous-wave laser-induced melting accompanied by shrinkage and resolidification of the metal powder layer are modeled using a temperature-transforming model. The liquid flow of the melted low-melting-point metal driven by capillary and gravity forces is also included in the physical model. The numerical results are validated by experimental results, and a detailed parametric study is performed. The effects of the moving heat source intensity, the scanning velocity, and the thickness of the powder layer on the sintering depth, the configuration of the heat affected zone, and the temperature distribution are discussed.

2005 ◽  
Author(s):  
◽  
Tiebing Chen

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Direct Selective Laser Sintering (SLS) is an emerging technology of Solid Freeform Fabrication (SFF) that 3-D parts are built from the metal-based powder bed with CAD data. A one-dimensional analytical model of melting in a two-component powder layer with finite thickness subjected to a constant heat flux heating and a two-dimensional numerical model of SLS of a two-component powder layer with a moving laser beam scanning were developed consecutively. Three-dimensional modeling of laser sintering of a two-component metal powder mixture under a moving Gaussian laser beam was investigated numerically at last. The effects of the moving heat source intensity, the scanning velocity, the thickness of the powder layer and the number of existing sintered layers underneath on the sintering depth, the configuration of the heat affected zone (HAZ) and the temperature distribution are discussed.


Author(s):  
Tiebing Chen ◽  
Yuwen Zhang

A three-dimensional numerical model of Selective Laser Sintering (SLS) of the metal powders for a single scan line induced by a moving laser beam interacted with a loose powder layer on top of the sintered metal layers is presented. The problem is modeled using a temperature-transforming model and the partial shrinkage induced by melting is accounted for. The heat losses at the top surface due to the natural convection and radiation are taken into account. The liquid flow of the molten low melting point metal powders, which is driven by capillary and gravity forces, is also considered and formulated by using Darcy’s law. The effects of the dominant processing parameters, such as the moving heat source intensity, scanning velocity and number of the existing sintered layers underneath are investigated. A parametric study is performed and the best combination of the processing parameters is recommended.


2006 ◽  
Vol 129 (3) ◽  
pp. 575-582 ◽  
Author(s):  
Tiebing Chen ◽  
Yuwen Zhang

A three-dimensional model of selective laser sintering of a two-component loose metal powder layer on top of previously sintered layers by a single-line laser scanning is presented. A temperature-transforming model is employed to model melting and resolidification accompanied by partial shrinkage during laser sintering. The heat losses at the top surface due to natural convection and radiation are taken into account. The liquid flow of the molten low-melting-point metal powders, which is driven by capillary and gravity forces, is also considered and formulated by using Darcy’s law. The effects of the dominant processing parameters, such as laser-beam intensity, scanning velocity, and number of the existing sintered layers underneath, are investigated.


Author(s):  
Bin Xiao ◽  
Yuwen Zhang

A three-dimensional model describing melting and resolidification of direct metal laser sintering of loose powders on top of sintered layers with a moving Gaussian laser beam is developed. Natural convection in the liquid pool driven by buoyancy and Marangoni effects is taken into account. A temperature transforming model is employed to model melting and resolidification in the laser sintering process. The continuity, momentum, and energy equations are solved using a finite volume method. The effects of dominant processing parameters including number of the existing sintered layers underneath, laser scanning velocity, and initial porosity on the sintering process are investigated.


2016 ◽  
Vol 685 ◽  
pp. 403-407 ◽  
Author(s):  
V.G. Smelov ◽  
A.V. Sotov ◽  
Serguei P. Murzin

In this article, selective laser sintering of fine metal powder of pure Ni with the size fractions 56 ... 80 microns was conducted. Algorithm development process of laser sintering of fine powders was created, allowing to obtain defect-free samples. Investigation of the material structure of obtained samples was carried out.


Author(s):  
Tiebing Chen ◽  
Yuwen Zhang

Multiple line laser scan sintering of a two-component metal powder layer on top of the sintered layers with a moving circular Gaussian laser beam is modeled numerically. The overlap between the adjacent scan lines to achieve enhanced bonding is taken into account. The binding between the newly sintered layer and existing sintered layers underneath through melting is also considered. The governing equation is formulated by a temperature-transforming model with partial shrinkage induced by melting considered. The liquid flow of the molten low melting point metal powders, which is driven by capillary and gravity forces, is formulated by Darcy’s law. The effects of the dominant processing parameters, including the moving laser beam intensity, scanning speed and number of the existing sintered layers underneath, on the shape of the heat affected zone (HAZ) are investigated. A parametric study is performed and the best combination of the processing parameters is recommended.


Author(s):  
Bin Xiao ◽  
Yuwen Zhang

A three dimensional model describing melting and resolidification of direct metal laser sintering of loose powders on top of sintered layers with a moving Gaussian laser beam is developed. Natural convection in the liquid pool driven by buoyancy and Marangoni effects is taken into account. A temperature transforming model is employed to model melting and resolidification in the laser sintering process. The continuity, momentum, and energy equations are solved using a finite volume method. Effects of dominant processing parameters including number of the existing sintered layers underneath, laser scanning velocity and initial porosity on the sintering process are investigated.


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