Cr-Al2O3 layered composites with a high electrical anisotropy prepared by repeated deformation processing

2005 ◽  
Vol 25 (1) ◽  
pp. 65-72 ◽  
Author(s):  
M. Leverkoehne ◽  
Aleš Dakskobler ◽  
M. Valant ◽  
R. Janssen ◽  
Tomaž Kosmač
Keyword(s):  
Electrical Anisotropy ◽  
Layered Composites ◽  
Deformation Processing

Electrical Anisotropy of Thin Metal Films Growing on Dielectric Substrates

2002 ◽  
Vol 7 (2) ◽  
pp. 45-52
Author(s):  
L. Jakučionis ◽  
V. Kleiza
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Uniaxial Anisotropy ◽  
Metal Films ◽  
Thin Layers ◽  
Electrical Anisotropy ◽  
Electrical Field ◽  
Dielectric Substrates ◽  
Unequal Probability ◽  
Conductive Thin Films

Electrical properties of conductive thin films, that are produced by vacuum evaporation on the dielectric substrates, and which properties depend on their thickness, usually are anisotropic i.e. they have uniaxial anisotropy. If the condensate grow on dielectric substrates on which plane electrical field E is created the transverse voltage U⊥ appears on the boundary of the film in the direction perpendicular to E. Transverse voltage U⊥ depends on the angle γ between the applied magnetic field H and axis of light magnetisation. When electric field E is applied to continuous or grid layers, U⊥ and resistance R of layers are changed by changing γ. It means that value of U⊥ is the measure of anisotropy magnitude. Increasing voltage U0 , which is created by E, U⊥ increases to certain magnitude and later decreases. The anisotropy of continuous thin layers is excited by inequality of conductivity tensor components σ0 ≠ σ⊥. The reason of anisotropy is explained by the model which shows that properties of grain boundaries are defined by unequal probability of transient of charge carrier.

Determination of the transverse shear stress in layered composites

2020 ◽  
Vol 86 (2) ◽  
pp. 44-53
Author(s):  
Yu. I. Dudarkov ◽  
M. V. Limonin
Keyword(s):  
Shear Stress ◽  
Transverse Shear ◽  
Composite Beam ◽  
Layered Composite ◽  
Equivalent Model ◽  
Shear Stresses ◽  
Transverse Shear Stress ◽  
Layered Composites ◽  
Laminate Composites ◽  
Transverse Shear Stresses

An engineering approach to estimation of the transverse shear stresses in layered composites is developed. The technique is based on the well-known D. I. Zhuravsky equation for shear stresses in an isotropic beam upon transverse bending. In general, application of this equation to a composite beam is incorrect due to the heterogeneity of the composite structure. According to the proposed method, at the first stage of its implementation, a transition to the equivalent model of a homogeneous beam is made, for which the Zhuravsky formula is valid. The transition is carried out by changing the shape of the cross section of the beam, provided that the bending stiffness and generalized elastic modulus remain the same. The calculated shear stresses in the equivalent beam are then converted to the stress values in the original composite beam from the equilibrium condition. The main equations and definitions of the method as well as the analytical equation for estimation of the transverse shear stress in a composite beam are presented. The method is verified by comparing the analytical solution and the results of the numerical solution of the problem by finite element method (FEM). It is shown that laminate stacking sequence has a significant impact both on the character and on the value of the transverse shear stress distribution. The limits of the applicability of the developed technique attributed to the conditions of the validity of the hypothesis of straight normal are considered. It is noted that under this hypothesis the shear stresses do not depend on the layer shear modulus, which explains the absence of this parameter in the obtained equation. The classical theory of laminate composites is based on the similar assumptions, which gives ground to use this equation for an approximate estimation of the transverse shear stresses in in a layered composite package.

scholarly journals Effect of Irradiation on Ni-Inconel/Incoloy Heterostructures in Multimetallic Layered Composites

2021 ◽  
Vol 547 ◽  
pp. 152778
Author(s):  
Shiddartha Paul ◽  
Daniel Schwen ◽  
Michael P. Short ◽  
Kasra Momeni
Keyword(s):  
Layered Composites

scholarly journals Interface-dependent nucleation in nanostructured layered composites

APL Materials ◽  
2013 ◽  
Vol 1 (3) ◽  
pp. 032112 ◽  
Author(s):  
Irene J. Beyerlein ◽  
Jian Wang ◽  
Ruifeng Zhang
Keyword(s):  
Layered Composites

scholarly journals Magnetotelluric study in the Los Lagos Region (Chile) to investigate volcano-tectonic processes in the Southern Andes

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Maria Jose Segovia ◽  
Daniel Diaz ◽  
Katarzyna Slezak ◽  
Felipe Zuñiga
Keyword(s):  
Electrical Resistivity ◽  
Three Dimensional ◽  
Phase Changes ◽  
Fault System ◽  
Electrical Anisotropy ◽  
Mountain Range ◽  
Southern Andes ◽  
Nazca Plate ◽  
First Results ◽  
Dimensional Parameters

AbstractTo analyze the process of subduction of the Nazca and South American plates in the area of the Southern Andes, and its relationship with the tectonic and volcanic regime of the place, magnetotelluric measurements were made through a transversal profile of the Chilean continental margin. The data-processing stage included the analysis of dimensional parameters, which as first results showed a three-dimensional environment for periods less than 1 s and two-dimensional for periods greater than 10 s. In addition, through the geomagnetic transfer function (tipper), the presence of structural electrical anisotropy was identified in the data. After the dimensional analysis, a deep electrical resistivity image was obtained by inverting a 2D and a 3D model. Surface conductive anomalies were obtained beneath the central depression related to the early dehydration of the slab and the serpentinization process of the mantle that coincides in location with a discontinuity in the electrical resistivity of a regional body that we identified as the Nazca plate. A shallow conductive body was located around the Calbuco volcano and was correlated with a magmatic chamber or reservoir which in turn appears to be connected to the Liquiñe Ofqui fault system and the Andean Transverse Fault system. In addition to the serpentinization process, when the oceanic crust reaches a depth of 80–100 km, the ascending fluids produced by the dehydration and phase changes of the minerals present in the oceanic plate produce basaltic melts in the wedge of the subcontinental mantle that give rise to an eclogitization process and this explains a large conductivity anomaly present beneath the main mountain range.

scholarly journals Preparation and Properties of Layered SiC-Graphene Composites for EDM

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2916
Author(s):  
Ondrej Hanzel ◽  
Zoltán Lenčéš ◽  
Peter Tatarko ◽  
Richard Sedlák ◽  
Ivo Dlouhý ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Surface Layer ◽  
Positive Influence ◽  
Layered Composite ◽  
Layered Composites ◽  
Good Adhesion ◽  
Electric Discharge Machining ◽  
Layer Sequence ◽  
The Individual ◽  
Scratch Tests

Three and five-layered silicon carbide-based composites containing 0, 5, and 15 wt.% of graphene nanoplatelets (GNPs) were prepared with the aim to obtain a sufficiently high electrical conductivity in the surface layer suitable for electric discharge machining (EDM). The layer sequence in the asymmetric three-layered composites was SiC/SiC-5GNPs/SiC-15GNPs, while in the symmetric five-layered composite, the order of layers was SiC-15GNPs/SiC-5GNPs/SiC/SiC-5GNPs/SiC-15GNPs. The layered samples were prepared by rapid hot-pressing (RHP) applying various pressures, and it was shown that for the preparation of dense 3- or 5-layered SiC/GNPs composites, at least 30 MPa of the applied load was required during sintering. The electrical conductivity of 3-layered and 5-layered composites increased significantly with increasing sintering pressure when measured on the SiC surface layer containing 15 wt.% of GNPs. The increasing GNPs content had a positive influence on the electrical conductivity of individual layers, while their instrumented hardness and elastic modulus decreased. The scratch tests confirmed that the materials consisted of well-defined layers with straight interfaces without any delamination, which suggests good adhesion between the individual layers.

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