scholarly journals The observation of surface-softening in Fe-based metallic glass

2011 ◽  
Vol 1300 ◽  
Author(s):  
Ansar Masood ◽  
V. Ström ◽  
L. Belova ◽  
J.J. Oak ◽  
J. Ågren ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Metallic Glass ◽  
Cooling Rate ◽  
Cross Section ◽  
Radial Dependence ◽  
Depth Sensing ◽  
Nano Indentation ◽  
Outermost Surface ◽  
The Cross ◽  
Significant Change

ABSTRACTDepth sensing nano-indentation investigations have been performed to determine the radial dependence of the hardness through the cross section of a Fe-based bulk glassy rod. We have found the hardness of the material decreases along radius from the centre to the outermost surface. This phenomenon is attributed to the ‘cooling rate induced surface softening’. Furthermore, a significant change (~15 %) in elastic modulus is noticed along the radius as well.

Study on the Porosity in Al-Zn-Mg-Cu High Strength Alloy DC Ingot

2016 ◽  
Vol 879 ◽  
pp. 790-794 ◽  
Author(s):  
Hui Xue Jiang ◽  
Hiromi Nagaumi ◽  
Shi Jie Guo ◽  
Chun Zou
Keyword(s):  
Cooling Rate ◽  
Cross Section ◽  
High Strength ◽  
Direct Chill ◽  
Thickness Direction ◽  
X Ray ◽  
Density Method ◽  
Width Direction ◽  
Strength Alloy ◽  
The Cross

An Al-Zn-Mg-Cu high strength alloy ingot produced by Direct-Chill casting was used in this study. The distribution of porosity in the cross section of the DC ingot was investigated by the precision density method (Archimeds’ principle), also X-ray microtomography technique was used to quantitatively analyze porosities in typical positions. The pattern in the cross section as well as in the thickness and width direction was obtained. The results show that: in the cross section of the ingot, porosity was increasing gradually from the surface to the center of the ingot; porosity shows an overall escalating trend from the surface to the center of the ingot both in thickness direction and in width direction; porosity was closely related to the cooling rate in the ingot; oxide inclusions have an effect on the formation of porosity to some extent.

Thermo-Mechanical Treatment to Improve Properties of Sisal Fibres for Composites

2010 ◽  
Vol 636-637 ◽  
pp. 253-259 ◽  
Author(s):  
L.A.C. Motta ◽  
Vanderley M. John ◽  
Vahan Agopyan
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Cross Section ◽  
Mechanical Treatment ◽  
Moisture Absorption ◽  
Thermo Mechanical Treatment ◽  
The Cross

The cross section variation, mechanical properties and moisture absorption of vegetable sisal fibres compressed at temperatures of 120, 160 and 200 °C were determined and compared with values obtained in non-compressed fibres. The thermo-mechanical treatment carried out resulted in a relevant increasing of fibre stiffness (elastic modulus) and decreasing of fibre moisture absorption.

A new method for analyzing data from continuous depth-sensing microindentation tests

1990 ◽  
Vol 5 (1) ◽  
pp. 123-126 ◽  
Author(s):  
D. L. Joslin ◽  
W. C. Oliver
Keyword(s):  
Surface Roughness ◽  
Elastic Modulus ◽  
Cross Sectional Area ◽  
New Method ◽  
Sectional Area ◽  
Depth Sensing ◽  
Cross Sectional ◽  
The Cross ◽  
Effect Of Surface

A new parameter, hardness/modulus2 (H/E2), has been derived from the equations used to calculate the hardness and elastic modulus from data taken during continuous depth-sensing microindentation tests. This paper discusses the use of this parameter to treat the data obtained from a sample whose surface roughness was of the same scale as the size of the indents. The resulting data were widely scattered. This scatter was reduced when the data were plotted in terms of H/E2 versus stiffness. The effect of surface roughness on the hardness and elastic modulus results is removed via stiffness measurements, provided single contacts are made between the indenter and the specimen. The function relating the cross-sectional area of the indenter versus the distance from its point is not required for calculation of H/E2, but the hardness and modulus cannot be determined separately. The parameter H/E2 indicates resistance to plastic penetration in this case.

scholarly journals INFLUENCE OF UNDERGROUND MINE PARAMETERS ON THE VALUE OF DAYLIGHT SURFACE SETTLEMENT OF UNDERMINED TERRITORY

2020 ◽  
Vol 11 (2) ◽  
pp. 5-18
Author(s):  
O. A Bogomolova ◽  
A. V Zhidelev
Keyword(s):  
Elastic Modulus ◽  
Cross Section ◽  
Lateral Pressure ◽  
Pressure Coefficient ◽  
Underground Mine ◽  
Cross Sectional ◽  
Lateral Pressure Coefficient ◽  
Vertical Displacements ◽  
The Cross ◽  
Sectional Shape

The article presents the analysis results of influence of shape and dimensions of cross-section, laying depth of mine, cross-section shape and dimensions of underground mine on the daylight surface settlement of undermined territory depending on the different numerical values of the soil lateral pressure coefficient of the surrounding soil. The numerical solution was obtained in an elastic setting using the computer programs «FEA» and «Stability». In the calculations, the elastic modulus of the enclosing rocks is taken equal to the dimensionless constant E /γ H = 500 (where γ; H are the rocks volumetric weight and laying depth of mine), therefore, the numerical values of the vertical displacements gained as a result of the calculations are also dimensionless. This approach is convenient for both quantitative and qualitative analysis, because not only specific values of vertical displacements are considered, but also change patterns of their values depending on changes in the numerical values of the variables of the calculated parameters. Assuming that the displacements in the linear formulation of the problem are inversely proportional to the elastic modulus, their magnitudes can be determined for any other value of E . It was established the vertical displacements of earth’s surface points located above the mine, provided that the depth of its laying is more than 15.2 m and the dimensions of the cross section are greater than 4×4 m, significantly depend on the shape of the cross section and the lateral pressure coefficient of the surrounding rock. In addition, smaller vertical precipitation of the daylight surface corresponds to an underground mine having an exotic and «non-technological» cross section in the deltoid form. Therefore, the problem arises is to obtain such an optimal cross-sectional shape of the mine that would ensure the minimum precipitation of the earth's surface. The cross-sectional shape of the mine must be as “technological" as possible according to its advancement. The subject of further research is the solution of these problems.

A Finite Element Model and Experimental Verification for the Mechanical Properties of 2.5-D Braided Composites

2007 ◽  
Vol 546-549 ◽  
pp. 1591-1596
Author(s):  
Wei Feng Dong ◽  
Yong Li ◽  
Jun Xiao
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Elastic Modulus ◽  
Finite Element Model ◽  
Cross Section ◽  
Element Model ◽  
Tensile Tests ◽  
Braided Composites ◽  
Finite Element Software ◽  
The Cross

As for 2.5-D layer-to-layer angle interlock braided composites, the cross section of the warp tow was represented in double-convex lens form, and the center line of the warp tow was along the sinusoid. The arranging characteristic of weft tow fibers along the cross section outline of the longitude fibers was studied in detail. A novel finite element model for 2.5-D braided composites was established to predict elastic modulus. The finite element software ANSYS was adopted to study the mechanical properties of the model and presented its stress nephogram, and the influence of the braided structure parameters on the elastic modulus of this material was analyzed in detail. To validate this model, qualified experimental samples were made by VARTM technique, and then tensile tests were performed to determine the mechanical properties. The results show that the conclusions of finite element method (FEM) fit well with the experimental values, and this model can be used to predict effectively the macro modulus of 2.5-D braided composites.

The Heterogeneity of Composition and Microstructure in Cast Large Sized 3104 Alloy Slab

2012 ◽  
Vol 217-219 ◽  
pp. 349-353
Author(s):  
Rui Yin Huang ◽  
Zhi Min Yin ◽  
Yuan Zhi Zhu
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Aluminium Alloy ◽  
Cooling Rate ◽  
Surface Area ◽  
Cross Section ◽  
Chemical Compositions ◽  
The Cross

Heterogeneity of composition and microstructure in cast large sized 3104 aluminium alloy slab were studied using AES-ICP, OM, SEM, etc. The results show that the cooling rate on the cross section of 3104 slab is different, macro-segregation is found in the different section in the slab .The content of Ti decreases gradually from the surface to about 1/4 thickness of the slab, then increases rapidly to the center of slab; other elements content increases gradually from the surface to the about 1/4 thickness and then decreases rapidly to the center; the grain size on the surface area is fine, and the grain size at the center is coarse , segregation of Mg is found within the grains; great amount compound is found to be of presence on the grain boundary, with chemical compositions of Al 87（FeMn）13 and Al83（FeMn）12Si5; The compound size at the surface area is comparatively smaller, and coarser at the centre of slab.

Propagation of a Pulse in a Nonhomogeneous Elastic Rod With Varying Cross Section

1978 ◽  
Vol 45 (4) ◽  
pp. 942-944 ◽  
Author(s):  
R. Y. Vasudeva ◽  
R. K. Bhaskara
Keyword(s):  
Elastic Modulus ◽  
Cross Section ◽  
Power Law ◽  
Pressure Pulse ◽  
Longitudinal Displacement ◽  
Elastic Rod ◽  
Material Density ◽  
The Cross

The problem of propagation of a pressure pulse in a nonhomogeneous elastic rod with varying cross section is discussed. The cross section, the material density, and the elastic modulus of the rod are taken to be varying in a power law form along the length of the rod and the longitudinal displacement is obtained through a method due to Keller and Keller.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Energy Distribution in Electron Beams

1972 ◽  
Vol 30 ◽  
pp. 568-569
Author(s):  
Tamotsu Ohno
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Cross Section ◽  
Integral Curve ◽  
Electron Beams ◽  
Electron Gun ◽  
Angular Divergence ◽  
Apparent Increase ◽  
Integral Width ◽  
The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

Sign in / Sign up

Export Citation Format

Share Document