scholarly journals Electrical response of La2/3-xLi3xTiO3 ceramics obtained by spark plasma sintering

2020 ◽  
Vol 233 ◽  
pp. 04003
Author(s):  
J. Silva-Pereira ◽  
F. Guerrero ◽  
Y. Romaguera-Barcelay ◽  
L. Aguilera ◽  
R.S. Silva ◽  
...  

The ceramic system La2/3-xLi3xTiO3 presents as an interesting candidate to be used as an electrolyte in solid-state Li-ion batteries. In this paper the electrical response of the ceramic, La2/3-xLi3xTiO3 with x = 0.11 is reported. La2/3-xLi3xTiO3 nanoparticles were synthesized by high energy milling and sintered by Spark Plasma Sintering from an amorphous phase. After sintering, the samples were structurally characterized by XRD and Raman techniques. Measurements of complex impedance varying frequency from 1 Hz to 10 MHz and temperature from 25 °C to 270 °C were performed. The study of DC conductivity allowed us to find the contributions to the total conductivity, grain, and grain boundary of the samples. From the activation energy values, it was possible to determine the conductive mechanism corresponding to the mobility of Li+ ions.

2021 ◽  
Vol 488 ◽  
pp. 229402
Author(s):  
Rakesh Elango ◽  
Arina Nadeina ◽  
François Cadiou ◽  
Vincent De Andrade ◽  
Arnaud Demortière ◽  
...  

2013 ◽  
Vol 1513 ◽  
Author(s):  
R.C. Picu ◽  
J.J. Gracio ◽  
G.T. Vincze ◽  
N. Mathew ◽  
T. Schubert ◽  
...  

ABSTRACTIn this work Al-SiC nanocomposites were prepared by high energy ball milling followed by spark plasma sintering of the powder. For this purpose Al micro-powder was mixed with 50 nm diameter SiC nanoparticles. The final composites had grains of approximately 100 nm dimensions, with SiC particles located mostly at grain boundaries. To characterize their mechanical behavior, uniaxial compression, micro- and nano-indentation were performed. Materials with 1vol% SiC as well as nanocrystalline Al produced by the same means with the composite were processed, tested and compared. AA1050 was also considered for reference. It was concluded that the yield stress of the nanocomposite with 1 vol% SiC is 10 times larger than that of regular pure Al (AA1050). Nanocrystalline Al without SiC and processed by the same method has a yield stress 7 times larger than AA1050. Therefore, the largest increase is due to the formation of nanograins, with the SiC particles’ role being primarily that of stabilizing the grains. This was demonstrated by performing annealing experiments at 150°C and 250°C for 2h, in separate experiments.


2022 ◽  
pp. 131671
Author(s):  
Dina V. Dudina ◽  
Tatyana F. Grigoreva ◽  
Vyacheslav I. Kvashnin ◽  
Evgeniya T. Devyatkina ◽  
Sergey V. Vosmerikov ◽  
...  

Author(s):  
Enrique Martínez-Franco ◽  
Ming Li ◽  
Ricardo Cuenca Álvarez ◽  
Jesús González Hernández ◽  
Chao Ma ◽  
...  

Metal matrix nanocomposites (MMNCs) are anticipated to offer significantly better performance than existing superalloys. Nickel/alumina nanocomposite samples were fabricated with a powder metallurgy method, combining high-energy ball milling (HEBM) and spark plasma sintering (SPS). The objective of this research is to determine the effect of alumina nanoparticle fraction and HEBM parameters on the powder preparation and sintering processes, and resultant microstructure and properties. Nickel-based powders containing various fractions (1, 5 and 15 vol.%) alumina nanoparticles were prepared by HEBM. The initial particle sizes were 44 μm and 50 nm for nickel and alumina, respectively. The milling process was conducted by starting with mixing at 250 rpm for 5 min, followed by cycling operation at high and low speeds (1200 rpm for 4 min and 150 rpm for 1 min). Samples at different milling times (30, 60, 90 and 120 min) of each composition were obtained. Scanning electron microscopy (SEM) was used to evaluate the dispersion of nanoparticles in the powders at different milling times. SPS technique was used for consolidation of the prepared powders. SEM images showed that alumina nanoparticles are homogeneously dispersed in the metal matrix in the sample containing 15 vol.% alumina. Hardness measurements in cross sections of SPSed samples showed higher values for Ni/Al2O3 MMNC compared to pure Ni.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1276 ◽  
Author(s):  
Dariusz Garbiec ◽  
Volf Leshchynsky ◽  
Alberto Colella ◽  
Paolo Matteazzi ◽  
Piotr Siwak

Combining high energy ball milling and spark plasma sintering is one of the most promising technologies in materials science. The mechanical alloying process enables the production of nanostructured composite powders that can be successfully spark plasma sintered in a very short time, while preserving the nanostructure and enhancing the mechanical properties of the composite. Composites with MAX phases are among the most promising materials. In this study, Ti/SiC composite powder was produced by high energy ball milling and then consolidated by spark plasma sintering. During both processes, Ti3SiC2, TiC and Ti5Si3 phases were formed. Scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction study showed that the phase composition of the spark plasma sintered composites consists mainly of Ti3SiC2 and a mixture of TiC and Ti5Si3 phases which have a different indentation size effect. The influence of the sintering temperature on the Ti-SiC composite structure and properties is defined. The effect of the Ti3SiC2 MAX phase grain growth was found at a sintering temperature of 1400–1450 °C. The indentation size effect at the nanoscale for Ti3SiC2, TiC+Ti5Si3 and SiC-Ti phases is analyzed on the basis of the strain gradient plasticity theory and the equation constants were defined.


2011 ◽  
Vol 56 (2) ◽  
pp. 109-113 ◽  
Author(s):  
V. N. Chuvil’deev ◽  
A. V. Moskvicheva ◽  
A. V. Nokhrin ◽  
G. V. Baranov ◽  
Yu. V. Blagoveshchenskii ◽  
...  

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