scholarly journals A synthesis concept for a nanostructured CoFe2O4/BaTiO3 composite: Towards multiferroics

2019 ◽  
Author(s):  
Roberto Köferstein
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Multiferroic Properties ◽  
Replication Method ◽  
Nanostructured Composite ◽  
Ferroic Properties

The synthesis of a periodically ordered, nanostructured composite consisting of CoFe2O4 and BaTiO3 is presented. In a first step, mesoporous CoFe2O4 is prepared by the structure replication method (nanocasting) using mesoporous KIT-6 silica as a structural mold.Subsequently, BaTiO3 is created inside the pores of CoFe2O4 by the citrate route, resulting ina well-ordered composite material of both phases. The two components are known for their distinct ferroic properties, namely ferrimagnetism (CoFe2O4) and ferroelectricity (BaTiO3), respectively. Therefore, this proof of synthesis concept offers new perspectives in the fabrication of composite materials with multiferroic properties.

Hydrogen Storage Properties of Magnesium Based Nanostructured/Amorphous Composite Materials

2003 ◽  
Vol 801 ◽  
Author(s):  
Ming Au
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Hydrogen Storage ◽  
Mechanical Alloying ◽  
Particle Morphology ◽  
New Materials ◽  
Nanostructured Composite ◽  
Different Temperatures ◽  
The Stability ◽  
Kinetics Of

ABSTRACTIn this work, nanostructured composite materials Mg-Ni, Mg-Ni-La, Mg-Ni-Ce and Mg-LaNi5 have been synthesized using the mechanical alloying process. The new materials produced have been investigated by X-ray diffraction (XRD), TEM, SEM and EDS for their phase compositions, crystal structure, grain size, particle morphology and the distribution of the catalyst elements. Hydrogen storage capacities and the hydriding-dehydriding kinetics of the new materials have been measured at different temperatures using a Sieverts apparatus. The results show that amorphous/nanostructured composite material Mg50%-Ni50% absorbs 5.89wt% within five minutes and desorbs 4.46% hydrogen within 50 minutes at 250°C respectively. Adding 5% La into Mg-Ni composite materials reduces the starting temperature of hydrogen absorption and desorption from 200°C to 25°C which suggests the formation of unstable hydrides. The composite material Mg80%-LaNi5 20% absorbs 1.96% hydrogen and releases 1.75 wt% hydrogen at 25°C. It is observed that mechanical alloying accelerates the hydrogenation kinetics of the magnesium based materials at low temperature, but a high temperature must be provided to release the absorbed hydrogen from the hydrided magnesium based materials. It is believed the dehydriding temperature is largely controlled by the thermodynamic configuration of magnesium hydride. Doping Mg-Ni nano/amorphous composite materials with lanthanum reduces the hydriding and dehydriding temperature. Although the stability of MgH2 can not be easily reduced by ball milling alone, the results suggest the thermodynamic properties of Mg-Ni nano/amorphous composite materials can be alternated by additives such as La or other effective elements. Further investigation toward understanding the mechanism of additives will be rewarded.

scholarly journals The study of the structure and properties of nanostructured biodegradable thermoplastic composite

2018 ◽  
Vol 80 (2) ◽  
pp. 302-306 ◽  
Author(s):  
N. A. Shcherbina ◽  
V. A. Taganova ◽  
E. V. Bychkova ◽  
S. Ya. Pichkidze
Keyword(s):  
Composite Material ◽  
Lactic Acid ◽  
Composite Materials ◽  
Relative Elongation ◽  
Thermoplastic Composite ◽  
Polymer Materials ◽  
Structure And Properties ◽  
Natural Mineral ◽  
Nanostructured Composite ◽  
Mineral Fillers

Increased requirements for polymer materials and the expansion of their application fields create the prerequisites for the creation of new composite materials. The most promising matrix for the biocomposite material is 2-hydroxypropionic (lactic) acid, the unique capabilities of which are manifested as a result of modification by inorganic mineral fillers of nanometric size. The combination of such properties as Biodegradability and biocompatibility is particularly valuable in this polymer. Nanostructured composite materials, consisting of polylactic acid and mineral fillers, acquire a significant improvement in properties compared to the properties of a pure polymer. Biodegradable films containing a layered natural mineral from the class of metasilicates were obtained by the method of irrigation of molding solutions. Trichloromethane was used as a solvent for the preparation of molding solution. The structure and properties of a nanostructured thermoplastic composite are studied. It is shown that the filler is evenly distributed in the polymer structure, affects the size of the crystal formations, the size of the crystallites increases. The introduction of a nanostructuring mineral into a biopolymer increases the thermal stability of the composite, which is due to the high resistance to high temperatures of the initial micro-reinforcing mineral filler, which does not decompose to a temperature of 1000-1100 0C. The influence of layered natural mineral from the class of metasilicates on the deformation and strength properties of biocompositeis established: the strength is maintained and the relative elongation at material rupture is slightly reduced. The ability to biodegradation and very low toxicity allow the use of nanostructured composite material based on 2-hydroxypropionic (lactic) acid in biomedical, pharmaceutical, environmental and industrial fields. The development of biodegradable composite material will solve the current domestic problems of polymers for medical purposes.

Study of the Composite Materials Optimal Structure Containing a Hollow Aluminum and Silica Microsphere Dependence on Humidity

2020 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Atyaksheva ◽  
Yermek Sarsikeyev ◽  
Anastasia Atyaksheva ◽  
Olga Galtseva ◽  
Alexander Rogachev
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Strength Function ◽  
Theory And Practice ◽  
Optimal Structure ◽  
Optimal Size ◽  
Structure And Properties ◽  
Power Functions ◽  
Silica Microsphere ◽  
Heat Engineering

Aims:: The main goals of this research are exploration of energy-efficient building materials when replacing natural materials with industrial waste and development of the theory and practice of obtaining light and ultra-light gravel materials based on mineral binders and waste dump ash and slag mixtures of hydraulic removal. Background.: Experimental data on the conditions of formation of gravel materials containing hollow aluminum and silica microsphere with opportunity of receipt of optimum structure and properties depending on humidity with the using of various binders are presented in this article. This article dwells on the scientific study of opportunity physical-mechanical properties of composite materials optimization are considered. Objective.: Composite material contains hollow aluminum and silica microsphere. Method.: The study is based on the application of the method of separation of power and heat engineering functions. The method is based on the use of the factor structure optimality, which takes into account the primary and secondary stress fields of the structural gravel material. This indicates the possibility of obtaining gravel material with the most uniform distribution of nano - and microparticles in the gravel material and the formation of stable matrices with minimization of stress concentrations. Experiments show that the thickness of the cement shell, which performs power functions, is directly related to the size of the raw granules. At the same time, the thickness of the cement crust, regardless of the type of binder, with increasing moisture content has a higher rate of formation for granules of larger diameter. Results.: The conditions for the formation of gravel composite materials containing a hollow aluminosilicate microsphere are studied. The optimal structure and properties of the gravel composite material were obtained. The dependence of the strength function on humidity and the type of binder has been investigated. The optimal size and shape of binary form of gravel material containing a hollow aluminosilicate microsphere with a minimum thickness of a cement shell and a maximum strength function was obtained. Conclusion.: Received structure allows to separate power and heat engineering functions in material and to minimize the content of the excited environment centers.

On the prospects of application of nanostructured heterophase polyfunctional composite materials inengine building industry

2019 ◽  
pp. 50-57
Author(s):  
O. B. Silchenko ◽  
M. V. Siluyanova ◽  
V. Е. Nizovtsev ◽  
D. A. Klimov ◽  
A. A. Kornilov
Keyword(s):  
Composite Materials ◽  
Gas Turbine ◽  
Developed Countries ◽  
The United States ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Nanostructured Composite ◽  
Polymer Metal ◽  
Long Operation ◽  
Prospects Of Application

The paper gives a brief review of properties and applications of developed extra-hard nanostructured composite materials and coatings based on them. The presentresearch suggestsaerospace applications of nanostructured composite materials based on carbides, carbonitrides and diboridesof transition and refractory metals. To improve the technical and economic performance of gas turbine engines, it is advisable to use new composite structural materials whose basic physicomechanical properties are several times superior to traditional ones. The greatest progress in developing new composites should be expected in the area of materials created on the basis of polymer, metal, intermetallic and ceramic matrices. Currently components and assemblies of gas turbine engines and multiple lighting power units with long operation life and durability will vigorously develop. Next-generation composites are studied in all developed countries, primarily in the United States and Japan.

Hierarchical ZSM-22/PHTS composite material and its hydro-isomerization performance in hydro-upgrading of gasoline

2021 ◽  
Author(s):  
Jiyuan Fan ◽  
Chengkun Xiao ◽  
Jinlin Mei ◽  
Cong Liu ◽  
Aijun Duan ◽  
...  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Impregnation Method ◽  
Molar Ratios

CoMo series catalysts based on ZSM-22/PHTS (ZP) composite materials with different SiO2/Al2O3 molar ratios were prepared via the impregnation method. The properties of the ZP material and the corresponding catalysts...

scholarly journals Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 145
Author(s):  
Lesław Kyzioł ◽  
Katarzyna Panasiuk ◽  
Grzegorz Hajdukiewicz ◽  
Krzysztof Dudzik
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Composite Material ◽  
Composite Materials ◽  
Testing Machine ◽  
Measurement Data ◽  
Entropy Method ◽  
Displacement Sensor ◽  
Metric Entropy ◽  
Plastic Phase

Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). Modern measurement methods and tools allow to determine the properties of the composite material, already during its design. The article presents the use of the method of acoustic emission and Kolmogorov-Sinai (K-S) metric entropy to determine the mechanical properties of composites. The tested materials were polyester-glass laminate without additives and with a 10% content of polyester-glass waste. The changes taking place in the composite material during loading were visualized using a piezoelectric sensor used in the acoustic emission method. Thanks to the analysis of the RMS parameter (root mean square of the acoustic emission signal), it is possible to determine the range of stresses at which significant changes occur in the material in terms of its use as a construction material. In the K-S entropy method, an important measuring tool is the extensometer, namely the displacement sensor built into it. The results obtained during the static tensile test with the use of an extensometer allow them to be used to calculate the K-S metric entropy. Many materials, including composite materials, do not have a yield point. In principle, there are no methods for determining the transition of a material from elastic to plastic phase. The authors showed that, with the use of a modern testing machine and very high-quality instrumentation to record measurement data using the Kolmogorov-Sinai (K-S) metric entropy method and the acoustic emission (AE) method, it is possible to determine the material transition from elastic to plastic phase. Determining the yield strength of composite materials is extremely important information when designing a structure.

scholarly journals Development of Detailed FE Numerical Models for Assessing the Replacement of Metal with Composite Materials Applied to an Executive Aircraft Wing

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 178
Author(s):  
Valerio Acanfora ◽  
Roberto Petillo ◽  
Salvatore Incognito ◽  
Gerardo Mario Mirra ◽  
Aniello Riccio
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Numerical Model ◽  
Numerical Models ◽  
Structural Performance ◽  
Aircraft Wing ◽  
Resin Infusion ◽  
Effectiveness Analysis ◽  
Liquid Resin Infusion ◽  
Process Constraints

This work provides a feasibility and effectiveness analysis, through numerical investigation, of metal replacement of primary components with composite material for an executive aircraft wing. In particular, benefits and disadvantages of replacing metal, usually adopted to manufacture this structural component, with composite material are explored. To accomplish this task, a detailed FEM numerical model of the composite aircraft wing was deployed by taking into account process constraints related to Liquid Resin Infusion, which was selected as the preferred manufacturing technique to fabricate the wing. We obtained a geometric and material layup definition for the CFRP components of the wing, which demonstrated that the replacement of the metal elements with composite materials did not affect the structural performance and can guarantee a substantial advantage for the structure in terms of weight reduction when compared to the equivalent metallic configuration, even for existing executive wing configurations.

Study on Mechanical Properties of the Composite Materials Film by Speckle Projection Method

2012 ◽  
Vol 496 ◽  
pp. 281-284
Author(s):  
Wen Wen Liu ◽  
Zhi Wang ◽  
Yun Hai Du ◽  
Xian Zhong Xu ◽  
Da Quan Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Projection Method ◽  
Dynamic Deformation ◽  
Calibration Method ◽  
Deformation Measurement ◽  
Lens Distortion

An improved accurate speckle projection method is used for study the mechanical properties of the composite material film in the paper. A system for deformation measurement is developed with the telecentric lenses, in which such conventional lens’ disadvantages such as lens distortion and perspective error will be diminished. Experiments are performed to validate the availability and reliability of the calibration method. The system can also be used to measure the dynamic deformation and then results are also given.

Stress Field of Semi-Infinite Interface Crack Tip of Double Dissimilar Orthotropic Composite Materials

2010 ◽  
Vol 97-101 ◽  
pp. 1223-1226
Author(s):  
Jun Lin Li ◽  
Shao Qin Zhang
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Interface Crack ◽  
Interfacial Crack ◽  
Crack Tip ◽  
Stress Fields ◽  
Displacement Fields ◽  
Orthotropic Composite ◽  
Stress Functions ◽  
Secular Equations

The problem of orthotropic composite materials semi-infinite interfacial crack was studied, by constructing new stress functions and employing the method of composite material complex. In the case that the secular equations’ discriminates the and theoretical solutions to the stress fields and the displacement fields near semi-infinite interface crack tip without oscillation and inter-embedding between the interfaces of the crack are obtained, a comparison with finite element example was done to verify the correction of theoretical solution.

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