scholarly journals Simultaneous Spark Plasma Sintering of Multiple Complex Shapes

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 557 ◽  
Author(s):  
Charles Manière ◽  
Elisa Torresani ◽  
Eugene Olevsky
Keyword(s):  
Spark Plasma Sintering ◽  
Energy Efficient ◽  
Large Scale ◽  
Alumina Powder ◽  
Homogeneous Microstructure ◽  
Plasma Sintering ◽  
Complex Shapes ◽  
Spark Plasma ◽  
Thermal Confinement ◽  
The Stability

This work addresses the two great challenges of the spark plasma sintering (SPS) process: The sintering of complex shapes and the simultaneous production of multiple parts. A new controllable interface method is employed to concurrently consolidate two nickel gear shapes by SPS. A graphite deformable sub-mold is specifically designed for the mutual densification of both complex parts in a unique 40 mm powder deformation space. An energy efficient SPS configuration is developed to allow the sintering of a large-scale powder assembly under electric current lower than 900 A. The stability of the developed process is studied by electro-thermal-mechanical (ETM) simulation. The ETM simulation reveals that homogeneous densification conditions can be attained by inserting an alumina powder at the sample/punches interfaces, enabling the energy efficient heating and the thermal confinement of the nickel powder. Finally, the feasibility of the fabrication of the two near net shape gears with a very homogeneous microstructure is demonstrated.

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.

scholarly journals Fully coupled electrothermal and mechanical simulation of the production of complex shapes by spark plasma sintering

2021 ◽  
Vol 41 (7) ◽  
pp. 4252-4263
Author(s):  
A. Van der Laan ◽  
R. Epherre ◽  
G. Chevallier ◽  
Y. Beynet ◽  
A. Weibel ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Mechanical Simulation ◽  
Plasma Sintering ◽  
Complex Shapes ◽  
Spark Plasma ◽  
Fully Coupled

scholarly journals Ultrahigh Temperature Flash Sintering of Binder-Less Tungsten Carbide within 6 s

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7655
Author(s):  
Huaijiu Deng ◽  
Mattia Biesuz ◽  
Monika Vilémová ◽  
Milad Kermani ◽  
Jakub Veverka ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Energy Efficient ◽  
Rapid Change ◽  
Thermal Inertia ◽  
Refractory Compounds ◽  
Flash Sintering ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Ultrahigh Temperature ◽  
Discharge Profile

We report on an ultrarapid (6 s) consolidation of binder-less WC using a novel Ultrahigh temperature Flash Sintering (UFS) approach. The UFS technique bridges the gap between electric resistance sintering (≪1 s) and flash spark plasma sintering (20–60 s). Compared to the well-established spark plasma sintering, the proposed approach results in improved energy efficiency with massive energy and time savings while maintaining a comparable relative density (94.6%) and Vickers hardness of 2124 HV. The novelty of this work relies on (i) multiple steps current discharge profile to suit the rapid change of electrical conductivity experienced by the sintering powder, (ii) upgraded low thermal inertia CFC dies and (iii) ultra-high consolidation temperature approaching 2750 °C. Compared to SPS process, the UFS process is highly energy efficient (≈200 times faster and it consumes ≈95% less energy) and it holds the promise of energy efficient and ultrafast consolidation of several conductive refractory compounds.

scholarly journals Fabrication of Cu-Based SiC Composites by Spark Plasma Sintering of Cu-Nitrate Coated SiC Powders

2017 ◽  
Vol 62 (2) ◽  
pp. 1407-1410
Author(s):  
Y.-K. Jeong ◽  
Y.S. Kim ◽  
S.-T. Oh
Keyword(s):  
Spark Plasma Sintering ◽  
Powder Mixture ◽  
Powder Processing ◽  
Sem Analysis ◽  
Homogeneous Microstructure ◽  
Dense Microstructure ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sic Composites

AbstractAn optimum route to fabricate the Cu-based SiC composites with homogeneous microstructure was investigated. Three methods for developing the densified composites with sound interface between Cu and SiC were compared on the basis of the resulting microstructures. Starting with three powder mixtures of elemental Cu and SiC, elemental Cu and PCS coated SiC or PCS and Cunitrate coated SiC was used to obtain Cu-based SiC composites. SEM analysis revealed that the composite fabricated by spark plasma sintering using elemental SiC and Cu powder mixture showed inhomogeneous microstructure. Conversely, dense microstructure with sound interface was observed in the sintered composites using powder mixture of pre-coated PCS and Cu-nitrate onto SiC. The relationship between powder processing and microstructure was discussed based on the role of coating layer for the wettability

Coupled Electro-Thermo-Mechanical Simulation for Multiple Pellet Fabrication Using Spark Plasma Sintering

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Bijan Nili ◽  
Ghatu Subhash ◽  
James S. Tulenko
Keyword(s):  
Temperature Distribution ◽  
Spark Plasma Sintering ◽  
Large Scale ◽  
Fe Model ◽  
Fuel Pellets ◽  
Plasma Sintering ◽  
Single Pellet ◽  
Die Surface ◽  
Spark Plasma ◽  
Tool Assembly

A coordinated experimental and computational analysis was undertaken to investigate the temperature field, heat generation, and stress distribution within a spark plasma sintering (SPS) tooling-specimen system during single- and multipellet fabrication of uranium dioxide (UO2) fuel pellets. Different SPS tool assembly configurations consisting of spacers, punches, pellets, and a die with single or multiple cavities were analyzed using ANSYS finite element (FE) software with coupled electro-thermo-mechanical modeling approach. For single-pellet manufacture, the importance of the die dimensions in relation to punch length and their influence on temperature distribution in the pellet were analyzed. The analysis was then extended to propose methods for reducing the overall power consumption of the SPS fabrication process by optimizing the dimensions and configurations of tooling for simultaneous sintering of multiple pellets in each processing cycle. For double-pellet manufacture, the effect of the center punch length (that separates the two pellets) on the temperature distribution in the pellets was investigated. Finally, for the multiple pellet fabrication, the optimum spacing between the pellets as well as the distance between the die cavities and the outer surface of the die wall were determined. A good agreement between the experimental data on the die surface temperature and FE model results was obtained. The current analysis may be utilized for further optimization of advanced tooling concepts to control temperature distribution and obtain uniform microstructure in fuel pellets in large-scale manufacturing using SPS process.

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