scholarly journals Magnetoelastic properties of epoxy resin based TbxHo0.9−xNd0.1 (Fe0.8Co0.2)1.93 particulate composites

2017 ◽  
Vol 35 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Z.R. Zhang ◽  
J.J. Liu ◽  
X.H. Song ◽  
F. Li ◽  
X.Y. Zhu ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particulate Composites ◽  
Particle Volume ◽  
Easy Magnetization ◽  
Magnetization Direction ◽  
Alloy Particles ◽  
Magnetoelastic Properties ◽  
Easy Magnetization Direction

AbstractTbxHo0.9−xNd0.1 (Fe0.8Co0.2)1.93 (0 ⩽ x ⩽ 0.40) particulate composites were prepared by embedding and aligning alloy particles in an epoxy matrix with and without a magnetic curing field. The magnetoelastic properties were investigated as functions of composition, particle volume fraction and macroscopic structure of the composite. The magnetic anisotropy compensation point was found to be around x = 0.25, where the easy magnetization direction (EMD) at room temperature was detected lying along ⟨ 1 1 1 ⟩ axis. The composite with ⟨ 1 1 1 ⟩ preferred orientation and pseudo-1-3 type structure was prepared under an applied magnetic field of 12 kOe. An enhanced magnetoelastic effect and large low-field magnetostriction λa, as high as 430 ppm at 3 kOe, were obtained for Tb0.25Ho0.65Nd0.1 (Fe0.8Co0.2)1.93 composite rod. The value of λa was of 72 % of its polycrystalline alloy (~595 ppm/3 kOe) although it only contained 30 vol.% of the alloy particles. This enhanced effect can be attributed to the larger λ111 (as compared to λ100), low magnetic anisotropy, easy magnetization direction (EMD) along the ⟨ 1 1 1 ⟩ axis and ⟨ 1 1 1 ⟩-textured orientation of the alloy particles as well as the chain-like structure of the composite. The good magnetoelastic properties of the composite, in spite of the fact that it contained only 30 vol.% of the alloy particles with light rare-earth Nd element in the insulating epoxy, would make it a potential material for magnetostriction application.

Multi-Scale Approach for Nonhomogeneous Microstructural Effects on Damage in Particulate Composites

2003 ◽  
Author(s):  
W. M. Cho ◽  
Y. W. Kwon ◽  
C. T. Liu
Keyword(s):  
Volume Fraction ◽  
Global Analysis ◽  
Particle Volume Fraction ◽  
Crack Tip ◽  
Particulate Composites ◽  
Local Analysis ◽  
Particle Volume ◽  
Damage Initiation ◽  
Volume Fractions ◽  
Multi Scale

This study investigated the effects of random and non-uniform particle distributions on the damage initiation and growth in particulate composites. Numerical specimens with either no crack or an existing crack were examined. For the cases with no crack, the effect of sizes of the representative area for non-uniform particle volume fractions was studied on the overall stress-strain curves and the results were compared with that of the specimen with uniform particle volume fractions. Other studies considered cracked specimens, either single edge crack or a center crack. The global-local approach was used along with multi-scale technique. The global analysis determined the deformations around the crack tip. Then, the local analysis evaluated the damage progress at the crack tip using the solution of the global analysis as boundary conditions. The results showed non-uniformed particle volume fractions in particulate composites caused the crack growth at lower applied loads than the uniform particle volume fraction. Statistical data were also plotted for the non-uniform particle volume fraction cases.

On Necessary Pumping Pressures for Industrial Process-Driven Particle-Laden Fluid Flows

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
T. I. Zohdi
Keyword(s):  
Flow Rate ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Industrial Process ◽  
Fluid Flows ◽  
Air Entrainment ◽  
Particulate Composites ◽  
Particle Volume ◽  
Derived Relations ◽  
High Reynolds

Due to increasing demands for faster and faster manufacturing of new complex materials, such as casting of particulate composites, the determination of pumping pressures needed for particle-laden fluids through channels is critical. In particular, the increase in viscosity as a function of the particle volume fraction can lead to system malfunction, due to an inability to deliver necessary pressures to pump the more viscous fluid through the system. This paper studies the pressure gradient needed to maintain a given flow rate, explicitly as a function of the volume fraction of particles present in the fluid. It is also crucial to control voids in the casted products, which can be traced to air-entrainment, spurious internal reactions, dewetting, etc., which can be traced to high Reynolds numbers. Accordingly, an expression for the resulting Reynolds number as a function of the particle volume fraction and flow rate is also developed. Numerical examples are provided to illustrate the practical use of the derived relations to characterize the necessary pumping pressures for process-driven, particle-laden fluid flows.

scholarly journals Dynamic magnetoelastic properties of TbxHo0.9−xNd0.1(Fe0.8Co0.2)1.93/epoxy composites

2019 ◽  
Vol 37 (2) ◽  
pp. 257-264 ◽  
Author(s):  
W.C. Shen ◽  
L.L. Lin ◽  
C.Y. Shen ◽  
S. Xing ◽  
Z.B. Pan
Keyword(s):  
Room Temperature ◽  
Bias Field ◽  
Material System ◽  
Magnetic Bias ◽  
Easy Magnetization ◽  
Magnetization Direction ◽  
Magnetoelastic Properties ◽  
Type Composite ◽  
Easy Magnetization Direction ◽  
Orientation Structure

AbstractTbxHo0.9−xNd0.1(Fe0.8Co0.2)1.93/epoxy (0 ⩽ x ⩽ 0.40) composites are fabricated in the presence of a magnetic field. The structural and dynamic magnetoelastic properties are investigated as a function of both magnetic bias field Hbias and frequency f at room temperature. The composites are formed as textured orientation structure of 1–3 type with 〈1 0 0〉 preferred orientation for x ⩽ 0.10 and 〈1 1 1〉-orientation for x ⩾ 0.25. The composites generally possess insignificant eddy-current losses for frequency up to 50 kHz, and their dynamic magnetoelastic properties depend greatly on Hbias. The elastic modulus (E3H and E3B) shows a maximum negative ΔE effect, along with a maximum d33, at a relatively low Hbias ~ 80 kA/m, contributed by the maximum motion of non-180° domain-wall. The 1–3 type composite for x ⩾ 0.25 shows an enhanced magnetoelastic effect in comparison with 0 to 3 type one, which can be principally ascribed to its easy magnetization direction (EMD) towards 〈1 1 1〉 axis and the formation of 〈1 1 1〉-texture-oriented structure in the composite. These attractive dynamic magnetoelastic properties, e.g., the low magnetic anisotropy and d33,max as high as 2.0 nm/A at a low Hbias ~ 80 kA/m, along with the light rare-earth Nd element existing in insulating polymer matrix, would make it a promising magnetostrictive material system.

Preparation and Magnetostriction of Epoxy-Bonded Pr(Fe0.4Co0.6)1.93 Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1370-1373
Author(s):  
X Liu ◽  
J.J Liu ◽  
R.R Lin ◽  
H.Y Yin ◽  
X.C Liu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Standard Strain ◽  
Easy Magnetization ◽  
Magnetization Direction ◽  
X Ray ◽  
Magnetoelastic Properties ◽  
Type Composite ◽  
Easy Magnetization Direction

The magnetostrictive Pr(Fe0.4Co0.6)1.93alloy with MgCu2-type structure, and its 0-3 and pseudo 1-3 type epoxy-bonded composites were fabricated by curing without and with a magnetic field. The structural, magnetic and magnetoelastic properties were investigated by means of x-ray diffraction, a vibrating sample magnetometer and a standard strain technique. The 0-3 type composite has a larger magnetostriction than the 1-3 composite has, which can be ascribed to the easy magnetization direction (EMD) not lying along direction.

Magnetostriction of Epoxy-Bonded Tb0.22Dy0.48Pr0.3(Fe0.9B0.1)1.93 Composites

2011 ◽  
Vol 295-297 ◽  
pp. 978-981
Author(s):  
Jin Jun Liu ◽  
Xiang Liu ◽  
Hong Yun Yin ◽  
Xin Cai Liu ◽  
Ping Zhan Si
Keyword(s):  
Magnetic Field ◽  
Room Temperature ◽  
Chain Structure ◽  
X Ray Diffraction ◽  
Standard Strain ◽  
Easy Magnetization ◽  
Magnetization Direction ◽  
X Ray ◽  
Magnetoelastic Properties ◽  
Easy Magnetization Direction

The magnetostrictive Tb0.22Dy0.48Pr0.3(Fe0.9B0.1)1.93 alloy, and its 0-3 and pseudo 1-3 type epoxy-bonded composites were fabricated by curing without and with a magnetic field. The structural, magnetic and magnetoelastic properties were in investigated by means of x-ray diffraction, an alternating gradient magnetometer and a standard strain technique. The easy magnetization direction (EMD) is lying along <111> direction at room temperature. The 1-3 type composites has a larger magnetostriction than the 0-3 composite has, which can be attributed to the <111>-textured orientation and the chain structure.

scholarly journals Performance improvement of double-tube gas cooler in CO2 refrigeration system using nanofluids

2015 ◽  
Vol 19 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Jahar Sarkar
Keyword(s):  
Performance Improvement ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Particle Volume ◽  
Transcritical Carbon Dioxide ◽  
The Given ◽  
Theoretical Analyses

The theoretical analyses of the double-tube gas cooler in transcritical carbon dioxide refrigeration cycle have been performed to study the performance improvement of gas cooler as well as CO2 cycle using Al2O3, TiO2, CuO and Cu nanofluids as coolants. Effects of various operating parameters (nanofluid inlet temperature and mass flow rate, CO2 pressure and particle volume fraction) are studied as well. Use of nanofluid as coolant in double-tube gas cooler of CO2 cycle improves the gas cooler effectiveness, cooling capacity and COP without penalty of pumping power. The CO2 cycle yields best performance using Al2O3-H2O as a coolant in double-tube gas cooler followed by TiO2-H2O, CuO-H2O and Cu-H2O. The maximum cooling COP improvement of transcritical CO2 cycle for Al2O3-H2O is 25.4%, whereas that for TiO2-H2O is 23.8%, for CuO-H2O is 20.2% and for Cu-H2O is 16.2% for the given ranges of study. Study shows that the nanofluid may effectively use as coolant in double-tube gas cooler to improve the performance of transcritical CO2 refrigeration cycle.

The Influences of Depositing Angles on TbFe Film Magnetic and Magnetostrictive Characteristics

2005 ◽  
Vol 475-479 ◽  
pp. 3757-3760
Author(s):  
Hong Chuan Jiang ◽  
Wan Li Zhang ◽  
Bin Peng ◽  
Wen Xu Zhang ◽  
Shi Qing Yang
Keyword(s):  
External Field ◽  
Magnetic Domain ◽  
Grain Morphology ◽  
Dc Magnetron Sputtering ◽  
Easy Magnetization ◽  
Magnetization Direction ◽  
Saturation Field ◽  
Domain Structures ◽  
Columnar Grain ◽  
Easy Magnetization Direction

In this paper, the influences of depositing angles on TbFe film magnetic and magnetostrictive characteristics were discussed. TbFe films were deposited by DC magnetron sputtering. With the decrease of depositing angles from 900 to 150, TbFe film in-plane magnetization measured at 1600kA.m-1 external field is greatly increased. With the decrease of depositing angles from 900 to 150, the magnetostrictive saturation field is decreased. TbFe film in-plane magnetostriction is improved when depositing angles are changed from 900 to 150. Magnetic domain structures detected by MFM indicates that film easy magnetization direction is gradually changed from perpendicular to parallel with the decrease of depositing angles. The variation of film magnetic and magnetostrictive performances can be explained by the oblique anisotropy associated with columnar grain morphology of the films.

A simulation and experimental study on particle volume fraction of PMMA suspension in centrifugal fields

2021 ◽  
Author(s):  
Yosephus Ardean Kurnianto Prayitno ◽  
Tong Zhao ◽  
Yoshiyuki Iso ◽  
Masahiro Takei
Keyword(s):  
Experimental Study ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particle Volume
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