Controlling and correlating the effect of grain size with the mechanical and electrochemical properties of Li7La3Zr2O12solid-state electrolyte

2017 ◽  
Vol 5 (40) ◽  
pp. 21491-21504 ◽  
Author(s):  
Asma Sharafi ◽  
Catherine G. Haslam ◽  
Robert D. Kerns ◽  
Jeff Wolfenstine ◽  
Jeff Sakamoto
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Electrochemical Properties ◽  
Current Density ◽  
Strong Correlation ◽  
Boundary Area

The strong correlation between LLZO grain size and the Li–LLZO stability as a function of Li plating rate is demonstrated. The increase in grain size reduces the grain boundary area and hence the number of possible failure points leading to an increased maximum tolerable current density.

The Microstructure and Electromigration behaviour of Al-0.35%Pd Interconnects

1994 ◽  
Vol 338 ◽  
Author(s):  
L.J. Elliott ◽  
D.C. Paine ◽  
J.H. Rose
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Critical Current ◽  
Current Density ◽  
Current Effect ◽  
Material Microstructure ◽  
Detailed Evaluation

ABSTRACTAl-Pd alloys have shown promise for improved IC interconnect manufacturability and reliability. However, there has been little detailed evaluation of microstructure and conductor failure reported for this material. Microstructure and electromigration behaviour of Al-0.35%Pd unpassivated interconnect was studied on films deposited at 250°C or 450°C and patterned into test structures of varying width. Samples were electrically stressed to failure at l×106A/cm2 or 2×106A/cm2. At 450°C, AlPdx precipitates form while at 250°C, palladium remains in solution and a larger grain size is obtained. Slit voids were found in 1μm and 3μm wide lines, though only in the finer lines were the failures transgranular. A very large increase in lifetime of 1μm wide lines with a decrease in current density from 2×106A/cm2 to l×106A/cm2 suggests a critical current effect due to grain boundary clusters in the these lines.

Grain Size and Chemical Composition Effects on the Grain Boundary Resistance of Ceria

2002 ◽  
Vol 730 ◽  
Author(s):  
Xiao-Dong Zhou ◽  
Harlan U. Anderson ◽  
Wayne Huebner
Keyword(s):  
Electrical Conductivity ◽  
Grain Size ◽  
Grain Boundary ◽  
Boundary Resistance ◽  
Impedance Spectra ◽  
Total Resistance ◽  
Boundary Area ◽  
Oxygen Ions ◽  
Composition Effects ◽  
Increasing Temperature

AbstractStudies related to the effects of grain size (30nm – 5.0μm) on the electrical conductivity of undoped CeO2 and Ce0.90Gd0.10O1.95 were performed. A series of impedance spectra as a function of temperature and grain size were analyzed. It was found that the ratio of the grain boundary resistance to the total resistance became lower with decreasing grain size, increasing temperature or increasing Gd content. For the case of Gd doped CeO2, the source of the grain boundary resistance may be due to the trapping of oxygen ions in the grain boundary area.

Simulation of the Kinetics of Grain-Boundary Nucleated Phase Transformations

2011 ◽  
Vol 172-174 ◽  
pp. 1128-1133 ◽  
Author(s):  
Eric A. Jägle ◽  
Eric J. Mittemeijer
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Phase Transformations ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Kinetic Models ◽  
Micro Structure ◽  
Boundary Area ◽  
Random Nucleation ◽  
Kinetics Of

The kinetics of phase transformations for which nucleation occurs on parent-micro-structure grain boundaries, and the resulting microstructures, were investigated by means ofgeometric simulations. The influences of parent microstructure grain-boundary area density,parent grain-size distribution and parent→product kinetics were analysed. Additionally, thesimulated kinetics were compared with predictions from two kinetic models, namely a modelproposed for spatially random nucleation and a model proposed for grain-boundary nucleation.It was found that the simulated transformed fraction as function of time lies in between the twomodel predictions for all investigated parent microstructures and parent→product kinetics.

Grain Size Effect in the Electrical Properties of Nanostructured Functional Oxides through Pressure Modification of the Spark Plasma Sintering Method

2011 ◽  
Vol 484 ◽  
pp. 107-116 ◽  
Author(s):  
D.V. Quach ◽  
S. Kim ◽  
R.A. De Souza ◽  
Manfred Martin ◽  
Z.A. Munir
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Spark Plasma Sintering ◽  
Functional Oxides ◽  
Boundary Area ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
20 Nm ◽  
Sintering Method

Through the use of a high-pressure modification of the spark plasma sintering method, it was possible to consolidate functional oxides (yttria- stabilized zirconia and doped ceria) to high densities and retain a grain size of < 20 nm. The role of the pressure on densification and on the grain size of the sintered samples was demonstrated. The pressure had a marked effect on density at relatively low temperature but an insignificant effect at relatively high temperature. It was found that when prepared with such small grain sizes, these oxides conduct protonically even at temperatures as low as room temperature. The dependence of the protonic conductivity is stronger dependence on grain size than what can be anticipated from a geometric consideration based on an increase in grain boundary area. This observation strongly suggests that factors other than an increase in grain boundary area play a role, a consideration that is being further investigated.

Sintering Simplified: Surface Area, Density, and Grain Size Relations

2016 ◽  
Vol 835 ◽  
pp. 50-75 ◽  
Author(s):  
Randall M. German
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Surface Area ◽  
Energy Condition ◽  
Energy Reduction ◽  
Boundary Area ◽  
Area Density ◽  
Natural Progression ◽  
Using Data ◽  
Mass Transport Mechanisms

Sintering involves several interactions as particles bond and enable microstructure evolution toward a minimized energy condition, resulting in a complex interplay of measurement parameters. Overriding the evolution is energy minimization, and from that perspective some simple relations emerge. The natural progression is determined by energy reduction, measured by surface area, density, and grain boundary area (grain size). Contrary to the usual sintering analysis that starts with atomic level mass transport mechanisms, presented here is an approach that links to global energy reduction during sintering to simple monitors. Initially sintering converts surface area into lower energy grain boundary area. Subsequently grain growth annihilates grain boundary area. Thus, grain boundary area peaks at intermediate sintered densities, while surface area continuously declines. The trajectory follows a straightforward dependence on density as illustrated using data for a wide variety of materials and consolidation conditions.

Interpretation of Profile and Intercept Counts in Microstructure Characterization

2008 ◽  
Vol 604-605 ◽  
pp. 403-410 ◽  
Author(s):  
Ivan Saxl ◽  
Vaclav Sklenička
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Unit Volume ◽  
Structural Characteristics ◽  
Mean Value ◽  
Careful Consideration ◽  
Boundary Area ◽  
Mean Grain Size ◽  
The Mean ◽  
Size Dispersion

The results of intercept and profile counts are commonly interpreted as a suitable estimates of the mean grain size as represented e.g. by the grain density V. The term grain size is not explicitly defined even when some relation to grain volume and/or mean grain breadth (the mean Ferret diameter) is tacitly assumed. However, the intercept count L is directly related to the mean value of grain boundary area per unit volume SV and the profile count A is, under relatively general assumptions, directly related to the mean value of grain junctions per unit volume LV. Their relation to V can be generally written as V = c¢(A)3/2 = c²(L)3, but the coefficients c¢ and c² strongly depend on the structural characteristics like grain size dispersion, anisotropy etc. and their evaluation is far from being simple. Consequently, whereas the reliable estimates of SV and LV result from intercept and profile counts, the estimate of grain density based on them requires a careful consideration.

Facet Topography and Dislocation Structure as a Possible Source for Electrical Heterogeneity in [001] TILT Bicrystals of YBa2Cu3O7-δ

1996 ◽  
Vol 54 ◽  
pp. 338-339
Author(s):  
I-Fei Tsu ◽  
D.L. Kaiser ◽  
S.E. Babcock
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Electromagnetic Properties ◽  
Length Scale ◽  
Density Values ◽  
Current Densities ◽  
Applied Fields ◽  
A Current

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.

scholarly journals Effects of Flash Sintering Parameters on Performance of Ceramic Insulator

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1157
Author(s):  
Yong Liu ◽  
Xingwang Huang
Keyword(s):  
Grain Size ◽  
Electric Field ◽  
Field Intensity ◽  
Current Density ◽  
Electric Field Intensity ◽  
Unit Cell ◽  
Uniform Structure ◽  
Ceramic Insulator ◽  
Flash Sintering ◽  
Ceramic Insulators

Ceramic outdoor insulators play an important role in electrical insulation and mechanical support because of good chemical and thermal stability, which have been widely used in power systems. However, the brittleness and surface discharge of ceramic material greatly limit the application of ceramic insulators. From the perspective of sintering technology, flash sintering technology is used to improve the performance of ceramic insulators. In this paper, the simulation model of producing the ceramic insulator by the flash sintering technology was set up. Material Studio was used to study the influence of electric field intensity and temperature on the alumina unit cell. COMSOL was used to study the influence of electric field intensity and current density on sintering speed, density and grain size. Obtained results showed that under high temperature and high voltage, the volume of the unit cell becomes smaller and the atoms are arranged more closely. The increase of current density can result in higher ceramic density and larger grain size. With the electric field intensity increasing, incubation time shows a decreasing tendency and energy consumption is reduced. Ceramic insulators with a higher uniform structure and a smaller grain size can show better dielectric performance and higher flashover voltage.

Grain Size Modification by Micro Rotary Swaging

2015 ◽  
Vol 651-653 ◽  
pp. 627-632 ◽  
Author(s):  
Svetlana Ishkina ◽  
Bernd Kuhfuss ◽  
Christian Schenck
Keyword(s):  
Grain Size ◽  
Longitudinal Section ◽  
Forming Process ◽  
Boundary Area ◽  
Cold Forming ◽  
Flat Surfaces ◽  
Rotary Swaging ◽  
2D Simulation ◽  
Physical Tests ◽  
Formed Part

Rotary swaging is a well established cold forming process e.g. in the automotive industry. In order to modify the material properties by swaging systematically, a new process of swaging with asymmetrical strokes of the forming dies is investigated. The newly developed tools feature flat surfaces and do not represent the geometry of the formed part as in conventional swaging. Numerical simulation and physical tests are carried out with special regard to the resulting geometry, mechanical properties and the microstructure. During these tests copper wires with diameter d0=1 mm are formed. Regarding the microstructure in the longitudinal section of formed specimens, elongation of grains in the central part and grain size reduction in the boundary area are observed. Furthermore, this approach opens up new possibilities to configure the geometry of wires. 2D-simulation is applied and discussed in the paper to investigate change of the processed geometry (cross-section) and shear strain distribution during the rotary swaging process.

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