A Simulation-Based Correlation of the Density and Thermal Conductivity of Objects Produced by Laser Sintering of Polymer Powders

Abstract

Numerical simulation of the laser-induced formation of shapes from polymer powders is achieved using an extension of a previously developed model of nonisothermal powder sintering. The extended model mimics the Selective Laser Sintering process which is used to produce a multiple layer part via laser irradiation. Model predictions of the physical features and effective thermophysical properties (porosity and thermal conductivity) of the object demonstrate sensitivity to several thermal processing parameters. Predicted values of the effective thermal conductivity and average porosity of the processed item are reported and correlated. [S1087-1357(00)00904-7]

Experimental analysis of selective laser sintering of polyamide powders: an energy perspective

“…This is because of a superficial melting of the material as well evidenced by the analysis of the line scanned. This could also be obtained by means of the thermal model given in equations (5) and (6). From these models it is clearly evident the surface temperature reaches its melting point if a Energy Density input is approximately 0.08 J/mm 2 .…”

“…As reviewed by Kandis et al [6], polymers are the most processed type of powders in SLS but the consolidation phenomena related to these materials seem to be the most complex among all those described in literature. They concern a deep interaction between heat, mass and momentum transfer as well as chemical modifications of the materials and variation of mechanical and thermophysical properties.…”

Finite-element analysis of effects of the laser-processed bimaterial component size on stresses and distortion

“…[9] Finiteelement models were also developed to carry out 1-D, 2-D, and three-dimensional (3-D) thermal analyses of SFF processes, especially in selective laser sintering. [10][11][12][13][14] These simulations provide substantial insights into how thermal gradients, thermal transient stresses, and residual stresses are developed in the fabrication of complex-shaped components using SFF processes. However, most of these models are limited to 1-D or 2-D cases, [6][7][8][9][10][11][12] and all of them only deal with processing of a single material.…”

“…[10][11][12][13][14] These simulations provide substantial insights into how thermal gradients, thermal transient stresses, and residual stresses are developed in the fabrication of complex-shaped components using SFF processes. However, most of these models are limited to 1-D or 2-D cases, [6][7][8][9][10][11][12] and all of them only deal with processing of a single material. [6][7][8][9][10][11][12][13][14] In contrast, we have recently carried out 3-D numerical simulation of laser processing of multiple-material components.…”

“…However, most of these models are limited to 1-D or 2-D cases, [6][7][8][9][10][11][12] and all of them only deal with processing of a single material. [6][7][8][9][10][11][12][13][14] In contrast, we have recently carried out 3-D numerical simulation of laser processing of multiple-material components. [15,16] The results from these previous studies [15,16] have indicated that the fabrication sequence, the laser scanning pattern, the scanning rate, and material properties (especially the thermal conductivity and the coefficient of thermal expansion) have strong influence on the temperature distribution, thermal transient stress, residual stress, and distortion of the multimaterial component.…”