Behaviour and Material Properties of the Grain Boundary on the Surface of an Anode during the Formation of a Dense Layer

2014 ◽  
Vol 508 ◽  
pp. 61-65 ◽  
Author(s):  
Han Bing He
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
Molten Salt ◽  
Material Properties ◽  
Dense Layer ◽  
Spinel Layer ◽  
The Core ◽  
Inert Anodes ◽  
Dense Ceramic ◽  
Molten Salt Electrolyte

EPMA was used to investigate the corrosion-evolution mechanism of a dense ceramic spinel layer on the surface of NiFe2O4-10NiO-based cermet inert anodes during electrolysis in a high-temperature molten salt electrolyte. The evolution behaviour of the grain boundary on the surface of a 22(20Ni-Cu)(NiFe2O4-10NiO) anode during the formation of a dense layer was also examined. The experimental results showed that the content of the Al element on the grain boundary at the bottom of both the NiFe2O4,NiAl2O4 and FeAl2O4 was higher than that in the core of the 22(20Ni-Cu)(NiFe2O4-10NiO) anode, and the content of the Al element between the Ni-Cu and the dense layer of NiFe2O4-NiAl2O4-FeAl2O4 was higher than that in both the NiFe2O4,NiAl2O4 and FeAl2O4. It was concluded that the production of the NiAl2O4 was due not only to the reaction of the NiO with the Al2O2F42-, but also to the oxidisation of the Ni, which then reacted with the Al2O2F42-.

Material Properties of Refractory Concrete under High Temperature

2015 ◽  
Vol 1126 ◽  
pp. 155-160
Author(s):  
Stanislav Šťastník ◽  
František Šot ◽  
Jiří Vala
Keyword(s):  
High Temperature ◽  
Solar Radiation ◽  
Physical Properties ◽  
Material Properties ◽  
Refractory Concrete ◽  
Thermal Storage ◽  
Thermal Transfer ◽  
The Core

The paper presents the validation of physical properties of refractory concrete with heavy filling, using the measurements under high temperature, assumed for the construction of a thermal storage. The whole system, consisting of the storage core and of the insulation container, is characterized by non-stationary thermal transfer, supplied from solar radiation into the core. The validation of behaviour of the system (including its sleeping state and the dynamics of charging and discharging) is needed for the optimization of its size parameters.

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

Grain boundary segregation in metals

1992 ◽  
Vol 50 (2) ◽  
pp. 1204-1205
Author(s):  
C.L. Briant
Keyword(s):  
Fracture Surface ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Material Properties ◽  
Electron Spectroscopy ◽  
High Vacuum ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
Local Concentration ◽  
The One

Grain boundary segregation is the process by which solute elements in a material diffuse to the grain boundaries, become trapped there, and increase their local concentration at the boundary over that in the bulk. As a result of this process this local concentration of the segregant at the grain boundary can be many orders of magnitude greater than the bulk concentration of the segregant. The importance of this problem lies in the fact that grain boundary segregation can affect many material properties such as fracture, corrosion, and grain growth.One of the best ways to study grain boundary segregation is with Auger electron spectroscopy. This spectroscopy is an extremely surface sensitive technique. When it is used to study grain boundary segregation the sample must first be fractured intergranularly in the high vacuum spectrometer. This fracture surface is then the one that is analyzed. The development of scanning Auger spectrometers have allowed researchers to first image the fracture surface that is created and then to perform analyses on individual grain boundaries.

Relationships Between Grain Boundary Structure and Material Properties

1980 ◽  
Vol 38 ◽  
pp. 366-369
Author(s):  
Brian Ralph ◽  
Barlow Claire ◽  
Nicola Ecob
Keyword(s):  
Grain Boundary ◽  
Material Properties ◽  
Main Property ◽  
Grain Structure ◽  
Boundary Structure ◽  
Grain Boundary Structure ◽  
Property Changes

This brief review seeks to summarize some of the main property changes which may be induced by altering the grain structure of materials. Where appropriate an interpretation is given of these changes in terms of current theories of grain boundary structure, and some examples from current studies are presented at the end of this paper.

scholarly journals Effect of material properties on heat transfer during cooling of high-temperature cylindrical bodies in liquids

2020 ◽  
Vol 1683 ◽  
pp. 032043
Author(s):  
I A Molotova ◽  
A R Zabirov ◽  
V V Yagov ◽  
M M Vinogradov ◽  
I A Belyaev
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Material Properties

scholarly journals Time-Response-Histogram-Based Feature of Magnetic Barkhausen Noise for Material Characterization Considering Influences of Grain and Grain Boundary under In Situ Tensile Test

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2350
Author(s):  
Jia Liu ◽  
Guiyun Tian ◽  
Bin Gao ◽  
Kun Zeng ◽  
Yongbing Xu ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Tensile Stress ◽  
Material Properties ◽  
Ferromagnetic Material ◽  
Silicon Steel ◽  
Time Response ◽  
Barkhausen Noise ◽  
Time Interval ◽  
Magnetic Barkhausen Noise

Stress is the crucial factor of ferromagnetic material failure origin. However, the nondestructive test methods to analyze the ferromagnetic material properties’ inhomogeneity on the microscopic scale with stress have not been obtained so far. In this study, magnetic Barkhausen noise (MBN) signals on different silicon steel sheet locations under in situ tensile tests were detected by a high-spatial-resolution magnetic probe. The domain-wall (DW) motion, grain, and grain boundary were detected using a magneto-optical Kerr (MOKE) image. The time characteristic of DW motion and MBN signals on different locations was varied during elastic deformation. Therefore, a time-response histogram is proposed in this work to show different DW motions inside the grain and around the grain boundary under low tensile stress. In order to separate the variation of magnetic properties affected by the grain and grain boundary under low tensile stress corresponding to MBN excitation, time-division was carried out to extract the root-mean-square (RMS), mean, and peak in the optimized time interval. The time-response histogram of MBN evaluated the silicon steel sheet’s inhomogeneous material properties, and provided a theoretical and experimental reference for ferromagnetic material properties under stress.

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