Journal Article10.1109/TMECH.2017.2705090
Analysis of Scattering and Absorption Characteristics of Metal Powder Layer for Selective Laser Sintering
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TL;DR: In this article, a modified sequential addition method is proposed for simulating the deposition of the metal powder layers used in selective laser sintering (SLS) process by means of Monte Carlo ray-tracing simulations and a gray-level co-occurrence matrix (GLCM) method.
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Abstract: A modified sequential addition method is proposed for simulating the deposition of the metal powder layers used in selective laser sintering (SLS) process. The scattering characteristics of the deposited layers are analyzed by means of Monte Carlo ray-tracing simulations and a gray-level co-occurrence matrix (GLCM) method. The validity of the proposed modeling approach is demonstrated by comparing simulation results for the gray-scale properties of the scattered image and the absorption coefficient of the metal powder layer with the experimental results obtained using a scanned laser pico-projection (SLPP) detection method and the simulation findings presented in the literature, respectively. Further simulations are then performed to investigate the effect of the metal powder packing density on the scattering characteristics and absorption of metal powder layers. The results show that a higher packing density leads to a lower scattering effect and a greater absorptivity. In addition, as compared with the characteristics of scattering and absorption of metal powder layers with different size distributions, it is shown that a bimodal distribution of the powder particle size results in the lowest scattering effect and the highest absorptivity given an appropriate specification of distribution parameters for powder structures used in SLS.
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Citations
Effects of sulfur concentration and Marangoni convection on melt-pool formation in transition mode of selective laser melting process
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TL;DR: In this paper, a three-dimensional thermal-fluid model is constructed to investigate the effects of Marangoni convection on the melt-pool formation during the Selective Laser Melting of SS316 powder.
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Packing quality of powder layer during counter-rolling-type powder spreading process in additive manufacturing
TL;DR: In this paper, the effect of the spreading speed of counter-rolling-type powder spreading is investigated by experiments and numerical simulations, and it is found that both the surface quality and packing density of the powder layer decrease with the increase of spreading speed.
137
Heat transfer simulations of selective laser melting process based on volumetric heat source with powder size consideration
Hong Chuong Tran,Yu-Lung Lo +1 more
TL;DR: In this article, a new volumetric heat source was proposed to estimate the size of the melt pool cross-section during Selective Laser Melting (SLM), which takes into account the effect of powder size distribution on the propagation of the laser energy through the depth of the metal powder layer.
134
Microstructure evolution during selective laser melting of metallic materials: A review
TL;DR: In this paper, a review of the recent research and development progress in selective laser melting of metallic materials with a focus on the process-microstructure relationship is presented, where the grain growth and porosity evolution as affected by laser processing parameters in the SLM process are discussed.
123
Systematic approach for determining optimal processing parameters to produce parts with high density in selective laser melting process
Hong Chuong Tran,Yu-Lung Lo +1 more
TL;DR: In this article, a circle packing design algorithm is employed to identify 48 representative combinations of the laser scanning speed and laser power for a commercial Nd:YAG selective laser melting (SLM) system.
64
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