Hybrid magnetoactive elastomer with a soft matrix and mixed powder

2018 ◽  
Vol 89 (1) ◽  
pp. 105-117 ◽  
Author(s):  
Dmitry Borin ◽  
Gennady Stepanov ◽  
Eike Dohmen
Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4373
Author(s):  
Yuqiang Feng ◽  
Zexu Du ◽  
Zhengfei Hu

This paper investigated 55 NiTi commercial alloy powder and 55 NiTi with 5% pure Ni mixed powder (55 NiTi + 5 Ni) coatings fabricated by laser cladding to study the effect of extra Ni addition on the microstructure and properties of the coating. The XRD and EDS results show that the major phases in the coatings were NiTi and Ni3Ti. Besides that, a second phase like Ni4Ti3, Fe2Ti, and NiTi2 was also detected, among which, NiTi2 was only found in 55 NiTi coating. The proportion of the phase composition in the coating was calculated via the software Image-Pro Plus. The hardness of the cladding layer reaches 770–830 HV, which was almost four times harder than the substrate, and the hardness of 55 NiTi + 5 Ni coating was around 8% higher than that of 55 NiTi coating. The wear resistance of the 55 NiTi + 5 Ni coating was also better; the wear mass loss decreased by about 13% and with a smaller friction coefficient compared with the 55 NiTi coating. These results are attributed to the solid solution strengthening effect caused by Ni addition and the second phase strengthening effect caused by the content increase of the Ni3Ti phase in the cladding layer.


2021 ◽  
Vol 11 (10) ◽  
pp. 4470
Author(s):  
Inna A. Belyaeva ◽  
Jürgen Klepp ◽  
Hartmut Lemmel ◽  
Mikhail Shamonin

Ultra-small-angle neutron scattering (USANS) experiments are reported on isotropic magnetoactive elastomer (MAE) samples with different concentrations of micrometer-sized iron particles in the presence of an in-plane magnetic field up to 350 mT. The effect of the magnetic field on the scattering curves is observed in the scattering vector range between 2.5 × 10−5 and 1.85 × 10−4 Å−1. It is found that the neutron scattering depends on the magnetization history (hysteresis). The relation of the observed changes to the magnetic-field-induced restructuring of the filler particles is discussed. The perspectives of employing USANS for investigations of the internal microstructure and its changes in magnetic field are considered.


2017 ◽  
Vol 17 (1) ◽  
pp. 143-146 ◽  
Author(s):  
S. Sobula ◽  
E. Olejnik ◽  
T. Tokarski

Abstract Wear resistance of TiC-cast steel metal matrix composite has been investigated. Composites were obtained with SHSB method known as SHS synthesis during casting. It has been shown the differences in wear between composite and base cast steel. The Miller slurry machine test were used to determine wear loss of the specimens. The slurry was composed of SiC and water. The worn surface of specimens after test, were studied by SEM. Experimental observation has shown that surface of composite zone is not homogenous and consist the matrix lakes. Microscopic observations revealed the long grooves with SiC particles indented in the base alloy area, and spalling pits in the composite area. Due to the presence of TiC carbides on composite layer, specimens with TiC reinforced cast steel exhibited higher abrasion resistance. The wear of TiC reinforced cast steel mechanism was initially by wearing of soft matrix and in second stage by polishing and spalling of TiC. Summary weight loss after 16hr test was 0,14÷0,23 g for composite specimens and 0,90 g for base steel.


2012 ◽  
Vol 501 ◽  
pp. 34-38 ◽  
Author(s):  
Kar Keng Lim ◽  
Roslinda Shamsudin ◽  
Muhammad Azmi Abdul Hamid

In this study, paper sludge ash, a waste from pulp and paper industry was used as a filler in fabricating Plaster of Paris/paper sludge ash composites. Various percentage of paper sludge ash was used, namely 1wt.%, 3wt.%, 5wt.% and 7wt.%. The effect of paper sludge ash on the compressive strength of the Plaster of Paris was studied. The mixed powder of paper sludge ash and Plaster of Paris were form into a 6 mm diameter and 12 mm height cylindrical samples. The composites were characterized theirs density where it shows that the density decreased as the amount of paper sludge ash increased. The compressive strength of the composites also decreased from 11.67 MPa without paper sludge ash addition to 0.50 MPa at 7wt.% paper sludge ash. However, the requirement of strength for Plaster of Paris in industry is between 8.96 MPa to 20.68 MPa. From the SEM observation, sample contain higher percentage of paper sludge ash exhibited more porosity. Therefore with the addition of 1wt.% of paper sludge ash into Plaster of Paris can be a promising construction material.


2011 ◽  
Vol 23 (3) ◽  
pp. 269-278 ◽  
Author(s):  
Bin Zhu ◽  
Christopher D Rahn ◽  
Charles E Bakis

Fluidic flexible matrix composite (F2MC) tubes have been shown to provide actuation and stiffness change in applications that require isolated tubes or multiple tubes embedded in a soft matrix. Structural applications often require stiff and strong composites, however, so this article addresses the actuation performance of F2MC tubes embedded in structural media. Two analytical models are developed based on Lekhnitskii’s solutions for a homogeneous orthotropic cylinder with axial force and pressure loading. These unit cell models are cylindrical and bilayer with the inner layer being a thick-walled F2MC tube and the outer layer representing the surrounding rigid composite and are composed of either homogeneous epoxy or a second FMC layer made with stiffer matrix material. The models are validated using ABAQUS. Free strain and blocked force are calculated for a variety of unit cell designs. The analytical results show that actuation performance is generally reduced compared to that of an isolated F2MC tube due to the radial and longitudinal constraints imposed by the surrounding structural medium. The free strain is generally two orders of magnitude smaller for an F2MC tube in structural media, requiring higher actuation pressures for bilayer F2MC structures. The blocking force of F2MC in either epoxy or composite is roughly an order of magnitude smaller than that of an isolated F2MC tube. The analysis shows a great degree of tailorability in actuation properties, so that the F2MC tube can be designed to minimize these differences. Higher actuation performance is achieved, for example, with a thick-walled F2MC tube, as opposed to the thin wall that maximizes performance in an isolated F2MC tube.


Author(s):  
Dmitry Yu Borin ◽  
Mikhail V Vaganov

Abstract First-order reversal curve (FORC) analysis allows one to investigate composite magnetic materials by decomposing the magnetic response of a whole sample into individual responses of the elementary objects comprising the sample. In this work, we apply this technique to analysing silicone elastomer composites reinforced with ferromagnetic microparticles possessing low intrinsic coercivity. Even though the material of such particles does not demonstrate significant magnetic hysteresis, the soft matrix of the elastomers allows for the translational mobility of the particles and enables their magnetomechanical hysteresis which renders into a wasp-waisted major magnetization loop of the whole sample. It is demonstrated that the FORC diagrams of the composites contain characteristic wing features arising from the collective hysteretic magnetization of the magnetically soft particles. The influence of the matrix elasticity and particle concentration on the shape of the wing feature is investigated, and an approach to interpreting experimental FORC diagrams of the magnetically soft magnetoactive elastomers is proposed. The experimental data are in qualitative agreement with the results of the simulation of the particle magnetization process obtained using a model comprised of two magnetically soft particles embedded in an elastic environment.


2015 ◽  
Vol 9 (7) ◽  
pp. 134 ◽  
Author(s):  
Siti Machmudah ◽  
M. Akmal Hadian ◽  
Lenno Samodro K. ◽  
Sugeng Winardi ◽  
Wahyudiono Wahyudiono ◽  
...  

Ceria-zirconia mixed oxides have been synthesized by hydrothermal synthesis process. Under hydrothermalconditions, water potential to control the direction of crystal growth, morphology, particle size and sizedistribution, because of the controllability of thermodynamics and transport properties by pressure andtemperature. The synthesis was carried out at temperatures of 150 − 200 oC and pressure of 5 MPa in a batchreactor. The reactor made of SUS 304 tube reactor with internal volume of 8.8 ml. The synthesized productswere calcined and characterized using SEM, XRD and FTIR. The results showed that the particles formed weresphere shaped particles with smooth morphology and the size of particle diameters were 35, 61, and 31 nm onaverage for reactions temperatures of 150, 180, and 200oC, respectively. The XRD pattern indicated thatceria-zirconia mixed powder was uniformly distributed in the structure to form a homogeneous solid solution.


1995 ◽  
Vol 6 (2) ◽  
pp. 103-110
Author(s):  
Makio Naito ◽  
Toyokazu Yokoyama ◽  
Akira Kondo ◽  
Hidehiro Kamiya ◽  
Toshio Iwahara ◽  
...  

2006 ◽  
Vol 527-529 ◽  
pp. 55-58 ◽  
Author(s):  
Kwan Mo Kim ◽  
Soo Hyung Seo ◽  
Jae Woo Kim ◽  
Joon Suk Song ◽  
Myung Hwan Oh ◽  
...  

The variation of nitrogen doping concentration was systematically investigated with respect to the amount of silicon powder added to the SiC powder for growing n-type 6H-SiC single crystal by the sublimation method. To change intentionally the Si content in the SiC powder, 0wt% to 2wt% of a silicon powder was added to first-thermal treated SiC powder and the mixed powder was treated again at 1800oC for 3 hours to eliminate excess free-metallic silicon. Nitrogen doped 6H-SiC single crystals were grown by using 2nd-thermal treatment SiC powder at fixed N2/(Ar + N2) (3%). The nitrogen doping concentration of 6H-SiC crystals increased with increasing Si content in the SiC powder. In this work, we could identify that the additional silicon powder in SiC powder plays a role in the enhancement of nitrogen doping in 6H-SiC crystals grown by the sublimation method.


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