scholarly journals Thermo-electro-mechanical modeling of spark plasma sintering processes accounting for grain boundary diffusion and surface diffusion

2021 ◽  
Vol 67 (5) ◽  
pp. 1395-1407
Author(s):  
A. S. Semenov ◽  
J. Trapp ◽  
M. Nöthe ◽  
O. Eberhardt ◽  
B. Kieback ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Surface Diffusion ◽  
Spark Plasma Sintering ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Experimental Results ◽  
Interparticle Contact ◽  
Mechanical Problem ◽  
Plasma Sintering ◽  
Spark Plasma

AbstractIn the present research, a numerical modeling approach of the initial stage of consolidation during spark plasma sintering on the microscopic scale is presented. The solution of a fully coupled thermo-electro-mechanical problem also accounting for grain boundary and surface diffusion is found by using a staggered way. The finite-element method is applied for solving the thermo-electro-mechanical problem while the finite-difference method is applied for the diffusion problem. A Lagrange-based non-linear formulation is used to deal with the detailed description of plastic and creep strain accumulation. The numerical model is developed for simulating the structural evolution of the involved particles during sintering of powder compacts taking into account both the free surface diffusion of the particles and the grain boundary diffusion at interparticle contact areas. The numerical results obtained by using the two-particle model—as a representative volume element of the powder—are compared with experimental results for the densification of a copper powder compact. The numerical and experimental results are in excellent agreement.

Grain boundary diffusion driven spark plasma sintering of nanocrystalline zirconia

2012 ◽  
Vol 38 (5) ◽  
pp. 4385-4389 ◽  
Author(s):  
Hanna Borodianska ◽  
Dmytro Demirskyi ◽  
Yoshio Sakka ◽  
Petre Badica ◽  
Oleg Vasylkiv
Keyword(s):  
Grain Boundary ◽  
Spark Plasma Sintering ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Nanocrystalline Zirconia

Grain-boundary diffusion coefficient in α-Al2O3 from spark plasma sintering tests: Evidence of collective motion of charge disconnections

2018 ◽  
Vol 44 (15) ◽  
pp. 19044-19048 ◽  
Author(s):  
Yoshihiro Tamura ◽  
Eugenio Zapata-Solvas ◽  
Bibi Malmal Moshtaghioun ◽  
Diego Gómez-García ◽  
Arturo Domínguez-Rodríguez
Keyword(s):  
Diffusion Coefficient ◽  
Grain Boundary ◽  
Spark Plasma Sintering ◽  
Boundary Diffusion ◽  
Collective Motion ◽  
Grain Boundary Diffusion ◽  
Plasma Sintering ◽  
Boundary Diffusion Coefficient ◽  
Spark Plasma ◽  
Α Al2o3

Densification mechanism involved during spark plasma sintering of a codoped α-alumina material: Part I. Formal sintering analysis

2009 ◽  
Vol 24 (1) ◽  
pp. 179-186 ◽  
Author(s):  
G. Bernard-Granger ◽  
C. Guizard
Keyword(s):  
Grain Boundary ◽  
Spark Plasma Sintering ◽  
Boundary Diffusion ◽  
Grain Boundary Sliding ◽  
Alumina Powder ◽  
Densification Mechanism ◽  
Material Part ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Boundary Sliding

Spark plasma sintering (SPS) of a codoped α-alumina powder has been investigated at temperatures between 850 and 1200 °C. The “grain size versus relative density” trajectory showed a significant grain growth as soon as the residual porosity closed. The densification mechanism was determined by anisothermal (investigation of the heating part of a SPS run) and isothermal methods. It was proposed that grain-boundary sliding, accommodated by oxygen grain-boundary diffusion, governed densification.

High Hardness BaCb-(BxOy/BN) Composites with 3D Mesh-Like Fine Grain-Boundary Structure by Reactive Spark Plasma Sintering

2012 ◽  
Vol 12 (2) ◽  
pp. 959-965 ◽  
Author(s):  
Oleg Vasylkiv ◽  
Hanna Borodianska ◽  
Petre Badica ◽  
Salvatore Grasso ◽  
Yoshio Sakka ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Spark Plasma Sintering ◽  
High Hardness ◽  
Boundary Structure ◽  
3D Mesh ◽  
Fine Grain ◽  
Grain Boundary Structure ◽  
Plasma Sintering ◽  
Spark Plasma

Interfacial Stability of a Spark Plasma Sintered Mo-Ti3SiC2 Layered Composite

2011 ◽  
Vol 211-212 ◽  
pp. 1051-1055 ◽  
Author(s):  
Tung Wai Leo Ngai ◽  
Wei Zheng ◽  
Chang Xu Hu ◽  
Heng Xie ◽  
Yuan Yuan Li
Keyword(s):  
Thermal Stability ◽  
Elevated Temperature ◽  
Spark Plasma Sintering ◽  
Layered Composite ◽  
Experimental Results ◽  
Interfacial Stability ◽  
Intermediate Layers ◽  
Plasma Sintering ◽  
Micro Cracks ◽  
Spark Plasma

Mo-Ti3SiC2layered composite was successfully prepared by spark plasma sintering at 1573 K for 20 min under a pressure of 50 MPa in vacuum. The Mo and Ti3SiC2layers were metallurgically bound together without noticeable superficial defects and micro-cracks at the interface. The fabricated Mo-Ti3SiC2layered composite was annealed at 1273 K under vacuum for 5, 10, 20 and 40 h to study the composite’s thermal stability. Three intermediate layers, Mo2C, MoSi2and Ti5Si3Cx, were formed at the interface. Experimental results showed that the Mo-Ti3SiC2layered composite prepared in this study has good interfacial stability at elevated temperature.

scholarly journals Flash Spark Plasma Sintering of 3YSZ: Modified Sintering Pathway and Impact on Grain Boundary Formation

2021 ◽  
Author(s):  
Thomas Hérisson de Beauvoir ◽  
Zakaria Ghomari ◽  
Geoffroy Chevallier ◽  
Andréas Flaureau ◽  
Alicia Weibel ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Spark Plasma Sintering ◽  
Boundary Formation ◽  
Plasma Sintering ◽  
Spark Plasma

Comparison of Spark Plasma Sintering and Hot Pressing of MgAlON

2007 ◽  
Vol 336-338 ◽  
pp. 1060-1061 ◽  
Author(s):  
Qing Huang ◽  
Hou Xing Zhang ◽  
Yong Huang ◽  
Hai Feng Li ◽  
Zhi Jian Wan
Keyword(s):  
Spark Plasma Sintering ◽  
Hot Pressing ◽  
Experimental Results ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
A Minor ◽  
Further Development

MgAlON ceramics were prepared by spark plasma sintering (SPS) and hot pressing (HP), respectively. It was found that SPSed MgAlON samples had a single MgAlON phase with almost no open pore while HPed MgAlON had a minor AlN phase. The strength of SPSed samples is higher than 500MP, being much higher than that of the HPed samples. The experimental results revealed that that SPS was a rapid and reliable process for the further development of MgAlON.

Peculiarity of Grain Boundary Diffusion of Fe and Co in Cu

2017 ◽  
Vol 380 ◽  
pp. 135-140 ◽  
Author(s):  
Ainur Khairullin ◽  
Valeriya Nikulkina ◽  
Sergei Zhevnenko ◽  
Alexey Rodin
Keyword(s):  
Surface Tension ◽  
Sample Preparation ◽  
Grain Boundary ◽  
Driving Force ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Experimental Results ◽  
Surface Tension Gradient ◽  
Extended Model ◽  
Negative Segregation

In this article new experimental evidences of anomalous grain boundary diffusion (GBD) of Fe and Co in Cu were describe. To demonstrate that the brief describing of results of grain boundary diffusion in Cu with following formulation of rules which can be established on the base of the analysis of the results is presented. Experimental results which are described here concern the attempt to change the effect negative segregation by microalloying by sulfur which did not change the situation and the diffusion through foil which allowed to demonstrate the absence of accelerated GB diffusion without specific sample preparation. It is shown that GBs do not give the additional effect to the flux of Fe and Co through the foil. The extended model of surface tension gradient as an additional driving force is described.

scholarly journals Limitations in the Grain Boundary Processing of the Recycled HDDR Nd-Fe-B System

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3528
Author(s):  
Awais Ikram ◽  
Muhammad Awais ◽  
Richard Sheridan ◽  
Allan Walton ◽  
Spomenka Kobe ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Diffusion Mechanism ◽  
Mass Gain ◽  
Grain Boundary Diffusion ◽  
Eutectic Alloys ◽  
Intergranular Phase ◽  
Spark Plasma ◽  
Diffusion Source ◽  
Secondary Annealing

Fully dense spark plasma sintered recycled and fresh HDDR Nd-Fe-B nanocrystalline bulk magnets were processed by surface grain boundary diffusion (GBD) treatment to further augment the coercivity and investigate the underlying diffusion mechanism. The fully dense SPS processed HDDR based magnets were placed in a crucible with varying the eutectic alloys Pr68Cu32 and Dy70Cu30 at 2–20 wt. % as direct diffusion source above the ternary transition temperature for GBD processing followed by secondary annealing. The changes in mass gain was analyzed and weighted against the magnetic properties. For the recycled magnet, the coercivity (HCi) values obtained after optimal GBDP yielded ~60% higher than the starting recycled HDDR powder and 17.5% higher than the SPS-ed processed magnets. The fresh MF-15P HDDR Nd-Fe-B based magnets gained 25–36% higher coercivities with Pr-Cu GBDP. The FEG-SEM investigation provided insight on the diffusion depth and EDXS analysis indicated the changes in matrix and intergranular phase composition within the diffusion zone. The mechanism of surface to grain boundary diffusion and the limitations to thorough grain boundary diffusion in the HDDR Nd-Fe-B based bulk magnets were detailed in this study.

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