Material optimization and post-processing of sand moulds manufactured by the selective laser sintering of binder-coated Al2O3 sands

2015 ◽  
Vol 225 ◽  
pp. 93-102 ◽  
Author(s):  
Shifeng Wen ◽  
Qiwen Shen ◽  
Qingsong Wei ◽  
Chunze Yan ◽  
Wei Zhu ◽  
...  
Keyword(s):  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Post Processing ◽  
Material Optimization

scholarly journals Fabrication of Natural Flake Graphite/Ceramic Composite Parts with Low Thermal Conductivity and High Strength by Selective Laser Sintering

2020 ◽  
Vol 10 (4) ◽  
pp. 1314
Author(s):  
Haihua Wu ◽  
Kui Chen ◽  
Yafeng Li ◽  
Chaoqun Ren ◽  
Yu Sun ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Ceramic Composite ◽  
Selective Laser Sintering ◽  
High Strength ◽  
Laser Sintering ◽  
Post Processing ◽  
Composite Part ◽  
Low Thermal Conductivity ◽  
Powder Composition

The 3D graphite/ceramic composite prototyping parts directly prepared by selective laser sintering (SLS) were porous, which led to poor strength and low thermal conductivity. In order to obtain low thermal conductivity and high strength, its thermal conductivity and compressive strength were adjusted by changing the mixture powder composition and adding post-processing. The result showed that the addition of silicon powder in the mixture powder could significantly improve the compressive strength and thermal conductivity. The addition of expanded graphite was beneficial to the formation of the closed pores in the matrix, which slightly reduced the compressive strength but significantly reduced the thermal conductivity. The 3D graphite/ceramic composite part showed an order of magnitude improvement in compressive strength (from 1.25 to 13.87 MPa) but relatively small change in thermal conductivity (from 1.40 to 2.12 W·m−1K−1) and density (from 0.53 to 1.13 g·cm−3) by post-processing. Reasonable mixture powder composition and post-processing were determined and realized the possibility of fabricating a 3D graphite/ceramic composite part with low thermal conductivity but high compressive strength. Furthermore, it could be used for the repeated casting of steel castings, and through the comparative analysis of casting defects, the prepared graphite/ceramic composite part was expected to replace water glass sand mold.

Research on Surface Quality Enhancement of Wood-Plastic Composite Powder SLS Parts by Post Processing

2010 ◽  
Vol 113-116 ◽  
pp. 508-511 ◽  
Author(s):  
Wei Liang Zeng ◽  
Yan Ling Guo
Keyword(s):  
Surface Quality ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Wood Plastic Composite ◽  
Post Processing ◽  
Plastic Composite ◽  
Rp Process ◽  
Sintering Properties

According to its advantages, such as low-cost and green biological etc., Wood-Plastic Composite(WPC) is more suitable for make parts by Selective Laser Sintering(SLS) rapid prototyping (RP) process. With optimal design of components, the parts made by WPC have good mechanical properties as well as with good laser sintering properties. In order to further improve the surface quality of the parts, the post-processing–infiltrating with wax–is introduced. After post-processing, the void fraction is decreased from 51% to 7%, surface quality has been greatly improved, Ra belows 13µm on average, after polishing the surface is more smooth and Ra belows 5µm averagely，compared to those without post processing, surface roughness decrease 22% and 73% respectively.

scholarly journals Selective Laser Sintering (SLS) and Post-Processing of Prosopis Chilensis/Polyethersulfone Composite (PCPC)

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3034
Author(s):  
Aboubaker I. B. Idriss ◽  
Jian Li ◽  
Yangwei Wang ◽  
Yanling Guo ◽  
Elkhawad A. Elfaki ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Particle Distribution ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Single Layer ◽  
Dimensional Accuracy ◽  
Laser Sintering ◽  
Raw Material ◽  
Post Processing ◽  
Prosopis Chilensis

The range of selective laser sintering (SLS) materials is currently limited, and the available materials are often of high cost. Moreover, the mechanical strength of wood–plastic SLS parts is low, which restricts the application of a SLS technology. A new composite material has been proposed to address these issues, while simultaneously valorizing agricultural and forestry waste. This composite presents several advantages, including reduced pollution associated with waste disposal and reduced CO2 emission with the SLS process in addition to good mechanical strength. In this article, a novel and low-cost Prosopis chilensis/polyethersulfone composite (PCPC) was used as a primary material for SLS. The formability of PCPC with various raw material ratios was investigated via single-layer experiments, while the mechanical properties and dimensional accuracy of the parts produced using the various PCPC ratios were evaluated. Further, the microstructure and particle distribution in the PCPC pieces were examined using scanning electron microscopy. The result showed that the SLS part produced via 10/90 (wt/wt) PCPC exhibited the best mechanical strength and forming quality compared to other ratios and pure polyethersulfone (PES), where bending and tensile strengths of 10.78 and 4.94 MPa were measured. To improve the mechanical strength, post-processing infiltration was used and the PCPC-waxed parts were enhanced to 12.38 MPa and 5.73 MPa for bending and tensile strength.

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.

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.

Relationship of Post Treatment Temperature and Tensile Strength for Selective Laser Sintering

2012 ◽  
Vol 155-156 ◽  
pp. 872-876 ◽  
Author(s):  
Jun Su ◽  
Xiao Jing Li ◽  
Pei Xin Qu
Keyword(s):  
Tensile Strength ◽  
Selective Laser Sintering ◽  
Research Result ◽  
Influence Factors ◽  
Past Research ◽  
Laser Sintering ◽  
Treatment Temperature ◽  
Processing Temperature ◽  
Post Processing ◽  
Coated Sand

Though SLS technology have got well development, the strength of the sintering prototype parts still need a lot of research. The lower strength of prototype parts mightl seriously affect the quality. The past research result shows that intensity of coated sand specimens of SLS sintering method is lower and cannot be used for metal casting, the sintered parts must be post-processed. In this study, author used the coated sand casting as the material of selective laser sintering experiment, studied the processing temperature and time on the mechanical properties of post-processing, and the influence on gas-forming property and collapsibility of the pieces. And combined with casting experimental to analyze the accuracy influence factors of precoated sand sintering parts and other performance assessment. Through the above analysis, we concluded that the influence law the post-processing of temperature on tensile strength of coated sand specimens under three different insulation temperature conditions.

scholarly journals 4D Printing of Magnetically Functionalized Chainmail for Exoskeletal Biomedical Applications

MRS Advances ◽  
2019 ◽  
Vol 4 (23) ◽  
pp. 1361-1366
Author(s):  
Anna R. Ploszajski ◽  
Richard Jackson ◽  
Mark Ransley ◽  
Mark Miodownik
Keyword(s):  
3D Printing ◽  
Biomedical Applications ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Processing Method ◽  
Assistive Devices ◽  
Post Processing ◽  
Magnetic Liquid ◽  
4D Printing ◽  
Multi Body

AbstractChainmail fabrics manufactured by selective laser sintering 3D printing have been magnetically functionalized to create a lightweight, 4D printed, actuating fabric. The post-processing method involves submerging the porous prints in commercial ferrofluid (oil-based magnetic liquid), followed by drying under heat. The actuation of the chainmail has been simulated using a rigid multi-body physics engine, and qualitatively matches experiment. Such magnetically actuating fabrics have potential to make thin, lightweight and comfortable wearable assistive devices.

Study on Mechanical Properties Enhancement of Post Processing WPC Powder Selective Laser Sintering Parts

2010 ◽  
Vol 113-116 ◽  
pp. 1845-1848 ◽  
Author(s):  
Wei Liang Zeng ◽  
Yan Ling Guo ◽  
Zong Sheng Xin ◽  
Kai Yi Jiang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Bending Strength ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Post Processing ◽  
Plastic Composite ◽  
Rp Process

In this paper, Wood-Plastic Composite(WPC) is successfully developed to make parts by Selective Laser Sintering(SLS) rapid prototyping (RP) process according to its advantages, such as green biological, wood texture and recycled, but the most important advantage is low-cost. With optimal design of components, the parts made by WPC have good mechanical properties as well as with good laser sintering properties. In order to further improve the mechanical properties of the parts, the post-processing–infiltrating with wax–is introduced. Through post-processing, the void fraction is decreased from from 51% to 7%, the mechanical properties are significantly improved, the average tensile strength, bending strength, impact strength are 1.214 MPa, 2.73 MPa and 1.4125 kJ/m2, compared with those without post processing, the tensile strength is 87 times, the bending strength is 4.7 times and impact strength is 2.5 times, respectively.

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