scholarly journals A Method for Obtaining the Complete Pole Figure With a Single Sample Using the Schulz Technique

1981 ◽  
Vol 4 (3) ◽  
pp. 159-169 ◽  
Author(s):  
M. Ortiz ◽  
J. D. Hermida
Keyword(s):  
Pole Figure ◽  
Diffraction Peak ◽  
Single Sample ◽  
Theoretical Expression ◽  
Cauchy Function ◽  
Alignment Errors ◽  
Good Agreement

A theoretical expression, which alIows the diffracted intensities to be corrected for defocusing, is derived from the convolution over the geometrical defocusing width of a diffraction peak fitted by a Cauchy function. Alignment errors are taken into account, and a good agreement between theoretical curves and experimental points is established.

scholarly journals An Investigation Into the Accuracy of the Vector Method by Comparison With ECP Measurements

1989 ◽  
Vol 10 (2) ◽  
pp. 117-134 ◽  
Author(s):  
R. Shimizu ◽  
J. Harase ◽  
K. Ohta
Keyword(s):  
Pole Figure ◽  
Direct Measurement ◽  
Orientation Distribution ◽  
Vector Method ◽  
Inversion Result ◽  
X Ray ◽  
Pole Figures ◽  
The Mean ◽  
Actual Orientation ◽  
Good Agreement

In an attempt to investigate the accuracy of the vector method for crystal texture analysis, a comparison has been made between the inversion result of the pole figure made by X-ray studies using the VM and the inversion result of the pole figure made by ECP. A comparison has been made between the inversion by the pole figure generated by direct measurement of orientations by ECP and the actual orientation distribution (measured by ECP) displayed in the same mode. The materials studied were recrystallized Fe–3% Si and Fe–50% Ni. The main findings were:• In the mean intensities of each individual Box, the inversion results of pole figures made from orientations determined by ECP were in good agreement with the inversion from (100) pole figures made by X-ray or actual orientation distribution (made by ECP) displayed in the same mode as the vector method.• For Fe–3% Si, quite a good agreement was obtained between the results inverted from X-ray pole figure and the direct measurement by ECP for the intensity distribution of minor texture component along ζ angle. It was concluded from these investigations that the inversion of the pole figure by the vector method is accurate enough for most practical purposes.

Determination of the Crystal Alignment of Pr-Fe-B Magnets Using the (105) X-Ray Pole Figure

2010 ◽  
Vol 660-661 ◽  
pp. 139-144 ◽  
Author(s):  
A.R.M. Castro ◽  
Hidetoshi Takiishi ◽  
Rubens Nunes de Faria Jr. ◽  
Nelson Batista de Lima
Keyword(s):  
Pole Figure ◽  
Permanent Magnets ◽  
X Ray ◽  
Sintered Magnets ◽  
Crystal Alignment ◽  
High Degree ◽  
Good Agreement

The crystallographic alignment of various permanent magnets has been investigated by X-ray pole figure analysis. Attempts have been made to measure the degree of alignment of these sintered magnets using the (105) reflection. It has been shown that the (105) pole figure can be used only to verify small differences in texture in magnets high degree of crystallographic alignment. A comparison between the measured and the calculated L105 index showed good agreement.

Radiation-induced changes in the structure of polypropylene

1959 ◽  
Vol 253 (1274) ◽  
pp. 322-330 ◽  
Keyword(s):  
Main Chain ◽  
High Energy ◽  
Theoretical Expression ◽  
Cross Linking ◽  
Gel Point ◽  
High Energy Radiation ◽  
Infra Red ◽  
Radiation Induced ◽  
Induced Changes ◽  
Good Agreement

Polypropylene undergoes both cross-linking and random main-chain fracture when exposed to high-energy radiation, the ratio of cross-linking to chain fracture varying with the dose received up to the gel point. An examination of the infra-red absorption spectrum of the irradiated polymer has shown that, in addition, vinylidine unsaturation ( R . R' /C=CH 2 ) is formed in the ratio of one vinylidene double bond to each chain fracture. The rate of main-chain fracture deduced from intrinsic viscosity measurements has been found to be initially (up to a dose of 35 Mrad) a function of the number of chain fractures produced, rather than proportional to the intensity of the radiation, as might have been expected from the behaviour of other polymers. After a dose of 50 to 60 Mrad an insoluble cross-linked gel can be separated from the polymer by solvent extraction, and the sol fraction decreases on further irradiation in accordance with the theoretical expression derived by Charlesby (1953), assuming that for every cross-link formed, one bond between two monomer units is broken. A mechanism for the radiation-induced changes is proposed, based upon the application of classical chemical kinetics, which is in good agreement with the observed phenomena.

scholarly journals The effect of influence of conservative and tangential axial forces on transverse vibrations of tapered vertical columns

2017 ◽  
Vol 4 (20) ◽  
pp. 333-342
Author(s):  
Jerzy Jaroszewicz ◽  
Leszek Radziszewski ◽  
Łukasz Dragun
Keyword(s):  
Boundary Value Problem ◽  
Natural Frequency ◽  
Critical Loads ◽  
Cauchy Function ◽  
Axial Forces ◽  
Transverse Vibrations ◽  
Cantilever Length ◽  
Tangential Forces ◽  
Elastically Supported ◽  
Good Agreement

The Cauchy function and characteristic series were applied to solve the boundary value problem of free transverse vibrations of vertically mounted, elastically supported tapered cantilever columns. The columns can be subjected to universal axial point loads which considerate – conservative and follower /tangential/ forces, and to distributed loads along the cantilever length. The general form of characteristic equation was obtained taking into account the shape of tapered cantilever for attached and elastically secured. Bernstein-Kieropian double and higher estimators of natural frequency and critical loads were calculated based on the first few coefficients of the characteristic series. Good agreement was obtained between the calculated natural frequency and the exact values available in the literature.

Effect of Melt Temperature on the Interfacial Thermal Resistance and Solidification Behaviour of Al/SiCp Composites

2014 ◽  
Vol 606 ◽  
pp. 35-40
Author(s):  
P. Gurusamy ◽  
S. Balasivanandha Prabu ◽  
R. Paskaramoorthy
Keyword(s):  
Thermal Resistance ◽  
Squeeze Casting ◽  
Solidification Time ◽  
Interfacial Thermal Resistance ◽  
Theoretical Expression ◽  
Melt Temperature ◽  
Squeeze Pressure ◽  
Solidification Behaviour ◽  
Resistance Value ◽  
Good Agreement

The effect of melt temperature on the interfacial thermal resistance and solidification behaviour of A356/10% SiCp during squeeze casting is studied. The melt pouring temperatures are considered in the investigation within the range of 750 - 900°C respectively. The squeeze pressure is kept constant at 100 MPa. It was observed that the solidification time increased with the melt temperature from 40 seconds at 750°C to 51 seconds at 900°C. The results also showed that the cooling rate decreased with melt temperatures. The solidification time calculated from the theoretical expression was found to be in good agreement with that obtained from the experimental cooling curves. The interfacial thermal resistance value increases from 0.000043 to 0.000203 m2 K/W when the melt temperature is increased from 750 to 900°C.

Heating Rate and Composition Dependence of Crystallization Temperature of Cu-Based Metallic Glasses

2016 ◽  
Vol 1141 ◽  
pp. 156-161 ◽  
Author(s):  
Supriya Kasyap ◽  
Sonal Prajapati ◽  
Arun Pratap
Keyword(s):  
Metallic Glass ◽  
Heating Rate ◽  
Power Law ◽  
Metallic Glasses ◽  
Crystallization Temperature ◽  
Composition Dependence ◽  
Theoretical Expression ◽  
Linear Variation ◽  
Peak Crystallization Temperature ◽  
Good Agreement

The variation of onset of crystallization temperature (Tx) and peak crystallization temperature (Tp) with heating rate (q) is studied. Tx and Tp vary in a power law behavior with heating rate (q) for Cu60 Zr20Ti20 metallic glass and these parameters show a linear variation for Cu60Zr40 metallic glass. The power law variation is expressed as Tx (or Tp) = T0 [q]y; where, q is the normalized heating rate, T0 is the Tx (or Tp) at a heating rate of 10Cmin-1. Further, the calculated values of Tx (or Tp) are found to be in good agreement with the experimental results. Hence, the power law relation is found to be an appropriate theoretical expression for the variation of crystallization temperature (Tx or Tp) with heating rate (q) for Cu60 Zr20Ti20 metallic glass. In addition to heating rate, the composition of a metallic glass also affects its crystallization temperature. It is observed that the characteristics temperatures shift towards higher values with increase in number of components.

Thermo-mechanical behavior of Fe thin films

2003 ◽  
Vol 795 ◽  
Author(s):  
Nail R. Chamsoutdinov ◽  
Amarante J. Böttger ◽  
Rob Delhez ◽  
Frans D. Tichelaar
Keyword(s):  
Mechanical Behavior ◽  
Diffraction Peak ◽  
Peak Width ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wafer Curvature ◽  
State Of Stress ◽  
Diffraction Peak Width ◽  
Scanning Electron ◽  
Good Agreement

ABSTRACTThe thermo-mechanical behavior of magnetron sputtered Fe polycrystalline films of thickness between 50 nm and 400 nm has been investigated. The state of stress has been determined by means of wafer curvature and X-ray diffraction (sin2ψ-method). Both methods are in good agreement for layers of thickness above 200 nm. For specimens of smaller layer thickness, however, the average stresses as measured by X-ray diffraction are systematically higher than those observed by wafer curvature experiments. The results can be interpreted in terms of differences in micro-strain (estimated using X-ray diffraction peak width analysis) and grain size as obtained by transmission and scanning electron microscopy. Thermal cycling experiments were performed between RT and 873 K. The effect of microstructure on thermo-mechanical properties was shown to be crucial.

DENSIFICATION AND GRAIN GROWTH OF NANOCRYSTALLINE NIAL POWDER DURING PRESSURELESS SINTERING

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2896-2904 ◽  
Author(s):  
A. MASHREGHY ◽  
M. M. MOSHKSAR
Keyword(s):  
Grain Growth ◽  
Profile Analysis ◽  
Diffraction Peak ◽  
Pressureless Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Grain Growth Model ◽  
Good Agreement ◽  
Nial Powder

Nanocrystalline NiAl powder was prepared by mechanical alloying. The prepared powder was cold compacted and sintered at different temperatures and times. The crystallite size of green and sintered compacts was estimated from X-Ray Diffraction peak profile analysis. Thereafter, the Generalized Parabolic Grain Growth model and Master Sintering Curve concept based on Combined Stage Sintering model were employed to investigate the grain growth and densification behavior of nanocrystalline NiAl powder during sintering, respectively. The results of modeling were in a very good agreement to that of experiment. Finally, by comparing the modeling results the sintering parameters were optimized.

A New Method for Determining the Vulcanization Characteristics of Rubber Compounds

1958 ◽  
Vol 31 (1) ◽  
pp. 105-116 ◽  
Author(s):  
J. Peter ◽  
W. Heidemann
Keyword(s):  
Shear Modulus ◽  
Test Sample ◽  
Single Sample ◽  
Dynamic Shear Modulus ◽  
Good Reproducibility ◽  
Dynamic Shear ◽  
Advantages And Disadvantages ◽  
Rubber Compounds ◽  
The Cost ◽  
Good Agreement

Abstract The complete course of the vulcanization curve is obtained by measuring the values of the dynamic shear modulus during a period while the test sample is held at the vulcanization temperature. The measurements are made about the position of zero distortion. The curves are in good agreement with those obtained by a step-cure method, and scorch data agree well with those obtained with the Mooney apparatus. The method has the following advantages and disadvantages. A. Advantages 1) The course of the vulcanization curve is established on a single sample without curing in stages. 2) Minimum material is required. 3) The test is quickly performed. 4) Good reproducibility is observed. 5) The unit lends itself readily to automatic recording so that one man can easily operate several instruments. B. Disadvantages 1) The apparatus should be operated by trained workers. 2) The cost of the apparatus is rather high.

Powder diffraction line profiles from the size and shape of nanocrystallites

2011 ◽  
Vol 44 (5) ◽  
pp. 945-953 ◽  
Author(s):  
K. R. Beyerlein ◽  
R. L. Snyder ◽  
P. Scardi
Keyword(s):  
Powder Diffraction ◽  
Numerical Procedure ◽  
Tangent Plane ◽  
Diffraction Peak ◽  
Line Profiles ◽  
Integration Technique ◽  
Debye Function ◽  
Size And Shape ◽  
Crystallite Sizes ◽  
Good Agreement

A numerical procedure to carry out the integral on the powder diffraction sphere in reciprocal space and obtain accurate powder diffraction peak profiles for small crystallites is presented. In doing so, the literature surrounding the effect of crystallite size and shape on the powder peak profile is briefly reviewed. Powder patterns simulated by this technique are compared with those calculated by the tangent plane approximation and Debye function for spherical, cubic and cylindrical crystallites having sizes of only a few nanometres. The tangent plane approximation is found to produce inaccurate peak profiles and peak positions in simulated patterns of the cubic and cylindrical nanocrystallites. This performance is in contrast to that of the proposed powder integration technique, which results in powder patterns that are in good agreement with those from the Debye function, for all crystallite sizes and shapes considered here.

Sign in / Sign up

Export Citation Format

Share Document