scholarly journals Development of SiC/PVB Composite Powders for Selective Laser Sintering Additive Manufacturing of SiC

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2012 ◽  
Author(s):  
Peng Zhou ◽  
Huilin Qi ◽  
Zhenye Zhu ◽  
Huang Qin ◽  
Hui Li ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Ceramic Composite ◽  
Composite Powder ◽  
Selective Laser Sintering ◽  
Particle Surface ◽  
Polyvinyl Butyral ◽  
Composite Powders ◽  
Sintering Additive ◽  
Composite Powder Material ◽  
Composite Granules

Subsphaeroidal SiC/polymer composite granules with good flowability for additive manufacturing/3D printing of SiC were prepared by ball milling with surface modification using polyvinyl butyral (PVB). PVB adheres to the particle surface of SiC to form a crosslinked network structure and keeps them combined with each other into light aggregates. The effects of PVB on the shape, size, phase composition, distribution and flowability of the polymer-ceramic composite powder were investigated in detail. Results show that the composite powder material has good laser absorptivity at wavelengths of lower than 500 nm.

scholarly journals 3D-printed valves to assist noninvasive ventilation procedures during the COVID-19 pandemic: a case study

2020 ◽  
Vol 4 (4) ◽  
pp. 193-202
Author(s):  
Guilherme Arthur Longhitano ◽  
Geovany Candido ◽  
Leonardo Mendes Ribeiro Machado ◽  
Paulo Inforçatti Neto ◽  
Marcelo Fernandes de Oliveira ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Noninvasive Ventilation ◽  
Selective Laser Sintering ◽  
Air Leakage ◽  
Final Model ◽  
Air Contamination ◽  
Sintering Additive ◽  
3D Printed ◽  
Full Face

Aim: To produce valves to be used with full-face snorkeling masks for noninvasive ventilation (NIV) procedure during the coronavirus disease 2019 (COVID-19) pandemic. Materials & methods: ISINNOVA’s Charlotte valves for full-face snorkeling masks used for NIV procedures were redesigned, produced by selective laser sintering additive manufacturing, and submitted to air leakage tests. Results: The final model assembly did not present air leakage during the NIV procedure on human models, minimizing risks of air contamination. Conclusion: This study shows the feasibility of using additive manufactured valves with snorkel facial masks to support health systems during COVID-19 and possible future pandemics.

Temperature Field Simulation of Wood Powder/PES Composite Powder Material

2015 ◽  
Vol 667 ◽  
pp. 218-223
Author(s):  
Yue Qiang Yu ◽  
Yan Ling Guo ◽  
Kai Yi Jiang
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
Powder Material ◽  
Laser Power ◽  
Composite Powder ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Powder Materials ◽  
Wood Powder ◽  
Composite Powder Material

In view of the physical process of the wood powder/PES composite powder material selective laser sintering forming ,this article establishes the plane moving Gaussian heat source as the input laser heat source model .Based on selective laser sintering wood powder/PES composite powder sintering theory and combined with thermal conductivity of composite powder, specific heat, density and other related theoretical analytical models .It establishes three dimensional finite element model of selective laser sintering process of wood powder/PES composite powder transient temperature field .The laser sintering simulation experiment of wood powder/PES composite powder under different laser power obtains temperature field distribution law of the wood powder/PES composite powder forming under different laser power distribution, and the influence of the forming parts forming quality of wood powder/PES composite powder materials caused by the temperature field. The simulation results also provide certain theoretical basis for the choice of laser power in the subsequent laser sintering experiment.

On the structure and properties of functional coatings from composite powders of the aluminum – silicon nitride system reinforced with a SiALON type phase

2021 ◽  
pp. 80-89
Author(s):  
T. I. Bobkova ◽  
A. I. Dmitryuk ◽  
E. A. Nezhensky ◽  
N. A. Lukyanova
Keyword(s):  
Silicon Nitride ◽  
Composite Powder ◽  
Development Process ◽  
Structure And Properties ◽  
Functional Coatings ◽  
Composite Powders ◽  
Distribution Of Elements ◽  
Composite Granules ◽  
Sprayed Coatings ◽  
Aluminum Silicon

The work studies development process of a composite powder of the aluminum – silicon nitride system and sprayed coatings using the mechanism of the formation of composite granules and the distribution of a hardening phase of the Sialon type in them. Various modes of powder composite mechanosynthesis are studied. The results of determining the hardness, chemical composition and distribution of elements in the resulting coating are given.

scholarly journals Mode I Fracture Toughness of Polyamide and Alumide Samples obtained by Selective Laser Sintering Additive Process

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 640 ◽  
Author(s):  
Dan Ioan Stoia ◽  
Liviu Marsavina ◽  
Emanoil Linul
Keyword(s):  
Fracture Toughness ◽  
Additive Manufacturing ◽  
Selective Laser Sintering ◽  
Dimensional Accuracy ◽  
Laser Sintering ◽  
Mode I ◽  
Additive Process ◽  
Mode I Fracture ◽  
Mode I Fracture Toughness ◽  
Sintering Additive

Selective Laser Sintering is a flexible additive manufacturing technology that can be used for the fabrication of high-resolution parts. Alongside the shape and dimension of the parts, the mechanical properties are essential for the majority of applications. Therefore, this paper investigates dimensional accuracy and mode I fracture toughness (KIC) of Single Edge Notch Bending samples under a Three Point Bending fixture, according to the ASTM D5045-14 standard. The work focuses on the influence of two major aspects of additive manufacturing: material type (Polyamide PA2200 and Alumide) and part orientation in the building environment (orientations of 0°, 45° and 90° are considered). The rest of the controllable parameters remains constant for all samples. The results reveal a direct link between the sample densities and the dimensional accuracy with orientation. The dimensional accuracy of the samples is also material dependent. For both materials, the angular orientation leads to significant anisotropic behavior in terms of KIC. Moreover, the type of material fundamentally influences the KIC values and the fracture mode. The obtained results can be used in the development of additive manufactured parts in order to obtain predictable dimensional tolerances and fracture properties.

Densification and Thermal Conductivity of Y2O3-Doped AlN Ceramics by Spark Plasma Sintering

2007 ◽  
Vol 352 ◽  
pp. 227-231 ◽  
Author(s):  
Qiang Shen ◽  
Z.D. Wei ◽  
Mei Juan Li ◽  
Lian Meng Zhang
Keyword(s):  
Thermal Conductivity ◽  
Grain Boundaries ◽  
Spark Plasma Sintering ◽  
Particle Surface ◽  
Boundary Phase ◽  
Homogeneous Microstructure ◽  
Densification Mechanism ◽  
Sintering Additive ◽  
Plasma Sintering ◽  
Spark Plasma

AlN ceramics doped with yttrium oxide (Y2O3) as the sintering additive were prepared via the spark plasma sintering (SPS) technique. The sintering behaviors and densification mechanism were mainly investigated. The results showed that Y2O3 addition could promote the AlN densification. Y2O3-doped AlN samples could be densified at low temperatures of 1600-1700oC in 20-25 minutes. The AlN samples were characterized with homogeneous microstructure. The Y-Al-O compounds were created on the grain boundaries due to the reactions between Y2O3 and Al2O3 on AlN particle surface. With increasing the sintering temperature, AlN grains grew up, and the location of grain boundaries as well as the phase compositions changed. The Y/Al ratio in the aluminates increased, from Y3Al5O12 to YAlO3 and to Y4Al2O9. High-density, the growth of AlN grains and the homogenous dispersion of boundary phase were helpful to improve the thermal conductivity of AlN ceramics. The thermal conductivity of 122Wm-1K-1 for the 4.0 mass%Y2O3-doped AlN sample was reached.

Hydrogen Generation by Hydrolysis of the Ball Milled Al-C-KCl Composite Powder in Distilled Water

2012 ◽  
Vol 519 ◽  
pp. 87-91 ◽  
Author(s):  
Xia Ni Huang ◽  
Zhang Han Wu ◽  
Ke Cao ◽  
Wen Zeng ◽  
Chun Ju Lv ◽  
...  
Keyword(s):  
Particle Size ◽  
Reaction Temperature ◽  
Fine Particle ◽  
Composite Powder ◽  
Hydrogen Generation ◽  
Aluminum Particle ◽  
Generation Rate ◽  
Composite Powders ◽  
Fine Particle Size ◽  
Hydrolysis Of

In the present investigation, the Al-C-KCl composite powders were prepared by a ball milling processing in an attempt to improve the hydrogen evolution capacity of aluminum in water. The results showed that the hydrogen generation reaction is affected by KCl amount, preparation processing, initial aluminum particle size and reaction temperature. Increasing KCl amount led to an increased hydrogen generation volume. The use of aluminum powder with a fine particle size could promote the aluminum hydrolysis reaction and get an increased hydrogen generation rate. The reaction temperature played an important role in hydrogen generation rate and the maximum hydrogen generation rate of 44.8 cm3 min-1g-1of Al was obtained at 75oC. The XRD results identified that the hydrolysis byproducts are bayerite (Al(OH)3) and boehmite (AlOOH).

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