Effects of the Processing Parameters on Porosity of Selective Laser Sintered Aliphatic Polycarbonate

2014 ◽  
Vol 915-916 ◽  
pp. 1000-1004 ◽  
Author(s):  
Xiao Hui Song ◽  
Yu Sheng Shi ◽  
Ping Hui Song ◽  
Qing Song Wei ◽  
Wei Li
Keyword(s):  
Mechanical Properties ◽  
Biomedical Engineering ◽  
Laser Power ◽  
Orthogonal Experiment ◽  
Selective Laser Sintering ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Optimal Parameters ◽  
Micro Structure ◽  
Aliphatic Polycarbonate

Selective Laser Sintering (SLS) has been successfully and broadly applied in biomedical engineering to fabricated biomedical part. And the porosity and microstructure of part can be controlled by main sintered parameters. This research focused aliphatic Polycarbonate (PC) sintered with SLS. According to the orthogonal experiment, the effect of laser power energy and interaction between main sintered parameters on porosity has been studied. Then the micro structure and mechanical properties of specimens sintered with the best optimal parameters have been analyzed.

scholarly journals Selective Laser Sintering of PA6: Effect of Powder Recoating on Fibre Orientation

2020 ◽  
Vol 4 (3) ◽  
pp. 108
Author(s):  
Tobias Heckner ◽  
Michael Seitz ◽  
Sven Robert Raisch ◽  
Gerrit Huelder ◽  
Peter Middendorf
Keyword(s):  
Computed Tomography ◽  
Mechanical Properties ◽  
Layer Thickness ◽  
Laser Power ◽  
Laser Energy ◽  
Fibre Orientation ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Shear Stresses ◽  
Imaging Results

In Selective Laser Sintering, fibres are strongly orientated during the powder recoating process. This effect leads to an additional increase of anisotropy in the final printed parts. This study investigates the influence of process parameter variation on the mechanical properties and the fibre orientation. A full factorial design of experiment was created to evaluate the processing parameters of recoating speed, layer thickness and laser power on the part’s modulus of elasticity. Based on the mechanical testing, computed tomography was applied to selected samples to investigate the process-induced fibre microstructure, and calculate the fibre orientation tensors. The results show increasing part stiffness in the deposition direction, with decreasing layer thickness and increasing laser power, while the recoating speed only shows little effect on the mechanical performance. This complies with computed tomography imaging results, which show an increase in fibre orientation with smaller layer thickness. With thinner layers, and hence smaller shear gaps, shear stresses induced by the roller during recoating increase significantly, leading to excessive fibre reorientation and alignment. The high level of fibre alignment implies an increase of strength and stiffness in the recoating direction. In addition, thinner layer thickness under constant laser energy density results in improved melting behaviour, and thus improved fibre consolidation, consequently further increasing the mechanical properties. Meanwhile, the parameters of recoating speed and laser power do not have a significant impact on fibre orientation within their applicable process windows.

scholarly journals Improvement on Selective Laser Sintering and Post-Processing of Polystyrene

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 956 ◽  
Author(s):  
Zhi Zeng ◽  
Xiaohu Deng ◽  
Jiangmei Cui ◽  
Hai Jiang ◽  
Shuo Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Orthogonal Experiment ◽  
Selective Laser Sintering ◽  
Single Layer ◽  
Dimensional Accuracy ◽  
Amorphous Polymers ◽  
Laser Sintering ◽  
Temperature Fields ◽  
Post Processing ◽  
Forming Process

Amorphous polymers are heavily utilized materials in selective laser sintering (SLS) due to their good dimensional accuracy. However, sintered parts of amorphous polymers cannot be used as functional parts owing to their poor forming performance, including their low relative densities and tensile strength. Therefore, post-processing methods are employed to enhance the mechanical properties of amorphous polymers SLS parts without damaging their relatively high dimensional accuracy. In this study, the forming process of selective laser sintering (SLS) and post-processing on polystyrene (PS) was investigated. The orthogonal experiment was designed to obtain the optimal combination of process parameters. The effect of a single process parameter and the laser volumetric energy density (LVED) on dimension accuracy and warpage of the sintered parts were also discussed. In addition, a three-dimensional (3D) thermal model was developed to analyze the temperature fields of single-layer SLS parts and PS powder sintering mechanism. Then, infiltrating with epoxy resin was employed to enhance the mechanical properties of the PS parts. Good resin-infiltrated formulation was obtained based on the mechanical property tests and fractured surface analysis. This research provides guidance for SLS process and post-processing technology in polymers.

The Optimization Design Study of Selective Laser Sintering Process Parameters on the Pro-Coated Sand Mold

2011 ◽  
Vol 55-57 ◽  
pp. 853-858
Author(s):  
Rong Cheng ◽  
Xiao Yu Wu ◽  
Jian Ping Zheng
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Process Variables ◽  
Scan Speed ◽  
Coated Sand

This paper presents experimental investigations on influence of important process parameters viz., laser power, scan speed, layer thickness, hatching space along with their interactions on dimensional accuracy of Selective Laser Sintering (SLS) processed pro-coated sand mold. It is observed that dimensional error is dominant along length and width direction of built mold. Optimum parameters setting to minimize percentage change in length and width of standard test specimen have been found out using Taguchi’s parameter design. Optimum process conditions are obtained by analysis of variance (ANOVA) is used to understand the significance of process variables affecting dimension accuracy. Scan speed and hatching space are found to be most significant process variables influencing the dimension accuracy in length and width. And laser power and layer thickness are less influence on the dimension accuracy. The optimum processing parameters are attained in this paper: laser power 11 W; scan speed 1200 mm/s; layer thickness 0.5 mm and hatching space 0.25 mm. It has been shown that, on average, the dimensional accuracy under this processing parameters combination could be improved by approximately up to 25% compared to other processing parameters combinations.

Preparation and selective laser sintering of bamboo flour/copolyester composite and post-processing

2015 ◽  
Vol 30 (8) ◽  
pp. 1045-1055 ◽  
Author(s):  
Dejin Zhao ◽  
Yanling Guo ◽  
Kaiyi Jiang ◽  
Hui Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Selective Laser Sintering ◽  
Single Layer ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Post Processing ◽  
New Type ◽  
Bamboo Flour

A new type of biocomposite, bamboo flour/copolyester (BFCP) composite for selective laser sintering (SLS™) was studied in this article. The bamboo flour was made from the bamboo residual of the bamboo production collected from a chopsticks factory. The BFCP composites of three mixture ratios (20/80, 25/75, and 30/70 (wt/wt)) were processed by SLS™. The proper processing parameters were determined by single-layer sintering methods. The mechanical properties of test specimens made from BFCP composites of three mixture ratios have been investigated. The results demonstrated that the mechanical properties of the specimens made by BFCP composite of 20/80 (wt/wt) were the best among those of the three mixture ratios and the average tensile strength, flexural strength, and impact strength of the specimens made from BFCP composite of 20/80 (wt/wt) were up to 4.14 MPa, 11.02 MPa, and 0.84 kJ m−2, respectively. The mechanical properties of specimens are extremely improved through infiltrating epoxy resin.

scholarly journals Effects of various processing parameters on the mechanical properties of sisal fiber/PES composites produced via selective laser sintering

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5710-5724
Author(s):  
Aboubaker I. B. Idriss ◽  
Jian Li ◽  
Yangwei Wang ◽  
Yanling Guo ◽  
Elkhawad A. Elfaki
Keyword(s):  
Mechanical Strength ◽  
Laser Power ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Sisal Fiber ◽  
Preheating Temperature ◽  
Scan Speed

A new type of sustainable material, i.e., a sisal fiber/poly-ether sulfone composite (SFPC), which is energy-efficient, environmentally friendly, and has a low cost, was developed for laser sintering additive manufacturing. This study was performed to explore the effects of the processing parameters on the SFPC composite parts produced via selective laser sintering (SLS). The effects of the laser sintering processing parameters, i.e., the preheating temperature, laser power, and scan speed, were studied. Bending and tensile testing of the SFPC specimens was successfully performed via SLS. The effect of the processing parameters on the SLS in terms of the mechanical strength of the laser-sintered parts was investigated. The results determined that the processing parameters had a significant effect on the mechanical strength of the sintered SFPC parts. When the preheating temperature and laser power were increased in the processing SLS system, the mechanical strength of the sintered SFPC parts was significantly increased. However, the scanning speed had an inverse proportional relationship to the mechanical strength of the SFPC SLS parts.

Rapid Development Technology of Mobile Phone Shell Basing on the Selective Laser Sintering

2012 ◽  
Vol 198-199 ◽  
pp. 123-127
Author(s):  
Chong You Feng ◽  
Jin Mei Zhang ◽  
Zheng Yu Zhang ◽  
Li Ping Li
Keyword(s):  
Mobile Phone ◽  
Orthogonal Experiment ◽  
Rapid Development ◽  
Selective Laser Sintering ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Technological Parameters ◽  
Optimum Processing ◽  
Development Technology ◽  
Warpage Deformation

According to the characteristics of mobile phone shell, the mobile phone products model provided by Pro/E software, analyzed the technological parameters of warpage deformation influence, and designed the orthogonal experiment plan, Verified the plan on SINTERSTATION HIQ + HS selective laser sintering system, carried out optimum processing parameters of the minimum warping deformation.

scholarly journals Emerging trend in manufacturing of 3D biomedical components using selective laser sintering: A review

2020 ◽  
Vol 184 ◽  
pp. 01047 ◽  
Author(s):  
Pankaj Kumar ◽  
Gazanfar Mustafa Ali syed
Keyword(s):  
Mechanical Properties ◽  
Laser Processing ◽  
Laser Power ◽  
Review Paper ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Sintering Process ◽  
Research Papers ◽  
Published Research

Additive manufacturing (also known as 3D printing) process is an emerging technique for the fabrication of biomedical components. Selective laser sintering or melting is one of the widely used additive printing technology for manufacturing of metallic and non-metallic components used in the industry. This review paper presents, a summary of the published research papers on the fabrication of biomedical components using selective laser sintering technique. Therefore, author meticulously attempted to investigate individual biocompatible material-wise review which includes Ti6Al4V, Ti-7.5 Mo alloy, β-Ti35Zr28Nb, PEEK, PA2200, and Polyamide/Hydroxyapatite. In addition, this article also explores the effects of the various laser sintering process parameters such as laser power, scanning speed, density of the material on the mechanical properties, tribological properties, porosity and surface roughness of the fabricated alloy. Moreover, the author also investigated challenges and future prospective of the laser processing of biomedical implants.

Sintering quality and parameters optimization of sisal fiber/PES composite fabricated by selective laser sintering (SLS)

2020 ◽  
pp. 089270572093917
Author(s):  
Aboubaker IB Idriss ◽  
Jian Li ◽  
Yanling Guo ◽  
Yangwei Wang ◽  
Xingdong Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Sisal Fiber ◽  
Optimum Parameters ◽  
Preheating Temperature

This article aims to improve the sintering quality of the sisal fiber/poly-(ether sulfone) (PES) composite (SFPC) part fabricated via selective laser sintering (SLS). The sisal fiber and PES powders were proposed as the feedstock of the SFPC powder bed for SLS. An orthogonal experimental methodology with four levels and five factors was applied to optimize the process parameters for the single-layer sintering experiment. The mechanical properties and accurate dimensions of the sintered part were tested using a universal testing machine and Vernier caliper. The preheating temperature, scanning speed, and laser power were selected as influencing factors on the mechanical properties and accuracy dimensions of the SFPC part. Furthermore, the influence factors on the quality of the sintered part were studied and analyzed. Additionally, the synthesis weighted scoring method was used to determine the optimum parameters of the SLS part. The results showed that the optimal parameters (factors) were preheating temperature of 82°C, scanning speed of 2 m s−1, laser power of 14 W, and laser wavelength of 10.6 μm. Thus, the quality of SFPC part was significantly enhanced when the optimum parameters were applied in SLS process. This article provided the main reference value for the choice of the process parameters of the biomass composite.

Thermal and Residual Stress Modelling of the Selective Laser Sintering Process

2002 ◽  
Vol 758 ◽  
Author(s):  
Ameer K. Ibraheem ◽  
Brian Derby ◽  
Phillip J. Withers
Keyword(s):  
Residual Stresses ◽  
Tool Steel ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Sintering Process ◽  
Strain Measurements ◽  
Scanning Rate ◽  
Thermal Residual Stresses

ABSTRACTThe production of functional tool steel components by selective laser sintering requires an understanding of the effects of the laser processing parameters on the microstructure evolution during the fabrication process. This would allow the production of tools that have predictable and reproducible microstructure, good mechanical properties and low residual stresses. In this paper, finite element modelling has been carried out to investigate the temperature distribution and residual stresses during laser sintering of hot-work tool steel powders. The effects of the laser power and scanning rate on the selective laser sintering process have been investigated. Thermal residual stresses accumulated during the process have been predicted and compared with strain measurements made using neutron diffraction.

scholarly journals Bioactive Tetracalcium Phosphate Scaffolds Fabricated by Selective Laser Sintering for Bone Regeneration Applications

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2268 ◽  
Author(s):  
Tian Qin ◽  
Xiaoqian Li ◽  
Hui Long ◽  
Shizhen Bin ◽  
Yong Xu
Keyword(s):  
Mechanical Properties ◽  
Bone Regeneration ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Laser Sintering ◽  
Scaffold Material ◽  
Promising Candidate ◽  
Tetracalcium Phosphate ◽  
Good Biocompatibility

Tetracalcium phosphate (TTCP), a potential biological scaffold material, has attracted increasing interest for bone regeneration applications due to its good biodegradability and biocompatibility. In this research, three-dimensional porous TTCP scaffolds were manufactured via selective laser sintering (SLS), and an in-depth and meticulous study on the influence of laser power on the microstructure and mechanical properties of TTCP scaffolds was performed. The results showed that the TTCP particles fused together and formed a solid object due to the decrease in the number of micro-pores in the scaffold as the laser power increased from 6 W to 9 W. The maximum compressive strength that the scaffold could withstand and the strength of the fracture toughness were 11.87 ± 0.64 MPa and 1.12 ± 0.1 MPa·m1/2, respectively. When the laser power increased from 9 W to 10 W, the TTCP grains grew abnormally, resulting in diminished mechanical properties. The bioactivity tests showed that the surfaces of the scaffolds were entirely covered by bone-like apatite layers after soaking in simulated body fluid (SBF) for three days, indicating that the scaffolds exhibit excellent bioactivity. Moreover, cell experiments showed that the TTCP scaffolds had good biocompatibility. This study indicated that SLS-fabricated TTCP scaffolds may be a promising candidate for bone regeneration applications.

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