Components Of Composite Materials Research Articles

Mineral fibre reinforced friction composites: effect of rockwool fibre on mechanical and tribological behaviour

Rockwool fibre, which is the important one of mineral fibres, shows tremendous potential as reinforcing components in composite materials. The purpose of this study is to evaluate the influence of rockwool fibre on physical, mechanical and tribological properties of friction composites. The friction composites were fabricated by a compression molder and evaluated by using a friction test machine. The experimental results show that friction coefficient of all specimens has an obvious increasing trend with the increasing of test temperature, the heat fade doesn’t occur in the test processes, and the existence of rockwool fibre could remarkable increase friction coefficient and restraint the heat fade at high temperature. Specimen F-3 containing 9 wt% rockwool fibres has the lowest wear rate, and presents best wear resistance. The worn surfaces morphologies were using the Scanning Electron Microscopy (SEM) for the sake of the tribological behavior and wear mechanism. The results reveal that the specimen F-3 presents a smoother friction surface with larger stable contact plateaus.

Studies on mechanical strengths of hemp-glass fibre reinforced epoxy composites

The objective of this study is to produce hemp and glass fiber incorporated composites with epoxy resin polymer matrix and to determine the mechanical strengths like, impact strength, tensile strength and flexural strength of the different samples. The hemp and glass fibres reinforced composite material components and products plays a major role in the field of automobile and construction sectors. By using hand layup process the different composite samples are fabricated as per the ASTM standards and the specimens were tested with aid of UTM tensile testing machine and charpy impact energy testing machine. The experimental reading of tested samples indicates that the untreated hemp and glass fibres composite exhibit the excellent tensile and flexural strengths. From the tested samples the SEM analysis was carried out to study the morphological properties

Carbon Materials from Technical Lignins: Recent Advances.

Lignin, a major component of lignocellulosic biomass, is generated in enormous amounts during the pulp production. It is also a major coproduct of second generation biofuels. The effective utilization of lignin is critical for the accelerated development of the advanced cellulosic biorefinery. Low cost and availability of lignin make it attractive precursor for preparation of a range of carbon materials, including activated carbons, activated carbon fibers (CF), structural CF, graphitic carbons or carbon black that could be used for environmental protection, as catalysts, in energy storage applications or as reinforcing components in advanced composite materials. Technical lignins are very diverse in terms of their molecular weight, structure, chemical reactivity, and chemical composition, which is a consequence of the different origin of the lignin and the various methods of lignin isolation. The inherent heterogeneity of lignin is the main obstacle to the preparation of high-performance CF. Although lignin-based CF still do not compete with polyacrylonitrile-derived CF in mechanical properties, they nevertheless provide new markets through high availability and low production costs. Alternatively, technical lignin could be used for production of carbon adsorbents, which have very high surface areas and pore volumes comparable to the best commercial activated carbons. These porous carbons are useful for purifying gas and aqueous media from organic pollutants or adsorption of heavy metal ions from aqueous solutions. They also could be used as catalysts or electrodes in electrochemical applications.

A Review on SHM Techniques and Current Challenges for Characteristic Investigation of Damage in Composite Material Components of Aviation Industry

Abstract Introduction of composites for aircraft fabrication has given the opportunity to all researchers and original equipment manufacturers to design a lightweight structure that will reduce both fuel consumption and harmful emissions. Reliability and cost of implementing structural health monitoring (SHM) systems are two critical parameters for the utilization of composite materials in the aviation industry. SHM of composite material components in the aviation industry not only lessens the downtime of aircraft but also enhances the possibility of damage detection in order to avoid severe failure. This article presents a case study of SHM systems that has been developed from research and implemented for the inspection and safety of recent aircraft structures. Compulsory components required for proper working of an SHM system and the basis and classification of defects in composite material components of aircraft are thoroughly explained in this article. Furthermore, characterization of SHM techniques (on the basis of functioning, advantages, and limitations) for crack detection and challenges of SHM systems are also part of this case study. An experimental work and its results have been well expressed regarding guided wave inspection using two different types of fiber-optic sensors for quasi-isotropic carbon fiber–reinforced plastic laminate. The ultimate goal of this article is to highlight the current challenges of SHM and promote the concept that SHM has great potential for research in the aviation industry.

Intrinsic transportation properties along and across the CNTs in self-supported 3D-CNT frameworks

Although carbon nanotube (CNT) is commonly used as an effective component in composite materials to improve the thermal and electrical transportations, the intrinsic thermal and electrical transportation properties of individual CNTs were seldom explored. By using orderly and randomly aligned multi-walled CNT (MWCNT) frameworks with self-supported constructions, herein we investigate the intrinsic thermal and electrical transportation properties of MWCNTs at high temperature ranges. Distinct temperature dependences in both thermal and electrical transportation properties along individual tubes or across the cross-linked tube joints were demonstrated. It is associated to the anisotropic phonon and carrier transportations at elevated temperatures. The present investigation is expected to improve the fundamental understanding of the transportation of CNTs and provide guidelines in design and fabrication for high-performance CNTs based composites.

Development and characterization of alkali treated abaca fiber reinforced friction composites

Abaca fibers show tremendous potential as reinforcing components in composite materials. The purpose of this study is to investigate the effect of abaca fiber content on physical, mechanical and tribological properties of abaca fiber reinforced friction composites. The friction composites were fabricated by a compression molder and investigated using a friction test machine. The experiment results show that surface treatment of abaca fibers could improve the mechanical properties of abaca fiber and interface bonding strength of the abaca fiber and composite matrix. Density of friction composites decreased with the increasing of abaca fiber content (0 wt%–4 wt%). The different content of abaca fibers had less effect on hardness of specimens, whereas large of impact strength. The specimen F3 with 3 wt% abaca fibers had the lowest wear rate and possessed the best wear resistance, followed by specimen F4 with 4 wt% abaca fibers. The worn surface morphologies were observed using the Scanning Electron Microscopy for study the tribological behavior and wear mechanism. The results show that a large amount of secondary contact plateaus presented on the worn surface of specimen F3 which had relatively smooth worn surface.

Formation of biodegradated polymers as components of future composite materials on the basis of shape memory alloy of medical appointment

The processes of formation of polymer polylactide or polyglycylidactide films for the subsequent creation of a layered composite with a biodegradable layer on the basis of a nickel-free shape memory alloy TiNbTaZr are studied. The structure of the samples was determined using an SEM. The correspondence of morphology of surfaces of and the substrate itself is noted. High adhesion of the polymer to the future basis of the developed composite material is supposed. The formed films is homogeneous and amorphous throughout the polymer volume. By varying the volume of solutions, it is possible to obtain films of a given thickness for any type of polymer, its molecular weight, and the solution concentration of the polymer in chloroform. Poly (glycolide-lactide) should be more plastic than polylactide.

Applications of ice‐templated ceramics

AbstractThe freeze‐cast ceramics process involves the use of an aqueous slurry in which ice acts as a fugitive template, providing control of the morphology of the resultant green body, which is then sintered. Here, we report a variety of applications of ice‐templated ceramics, showcasing the versatility of the process. Applications include: as a suitable scaffold for silver loading and release at concentrations that could show antibacterial properties; as a component of a robust composite material with negative thermal expansion but reduced material cost; as thin porous structures for dye‐sensitized solar cells.

Composite material components damaged by impact loading: a methodology for the assessment of their residual elastic properties

Purpose: Detection and evaluation of damage due to impact or fatigue loading in components made by composite materials is one of the main concern for automotive engineers. We focus on damage due to impact loading on long fibre, plastic matrix composite, as they represent one of the most interesting development solution for automotive components toward lightweight structure that in turn means reduction of fuel consumption and of Green House Gas emissions. Design/methodology/approach: An innovative simplified methodology is proposed, based on the impact and repeated impact behaviour of composite material, for the evaluation of the induced damage and of material residual elastic properties. The investigated composite laminate is made of eight twill-wave carbon fabrics impregnated with epoxy resin. The methodology consists of two phases: at first the identification of the impact response. Composite plates have been impacted at different energy levels and residual elastic properties measured through standard tensile tests. The relationship between impact energy and residual elastic properties is obtained. Then the exploration impact load is identified, large enough to give a well-defined picture of the suffered damage but soft enough to do not induce further damage in the composite laminate. Findings: This exploration impact test and the Damage Index (DI) value, as interpretation key, leads to a prediction of the local residual elastic properties in the damaged area. The proposed methodology has been validated on plate specimens. A strict correlation is found between the predicted and the actual residual elastic properties of the damaged composite plate. Practical implications: Subsequently it has been applied to a composite beam, with a omega shape transverse section, that can be considered as a demonstrator for a typical beam used in the car body frame. Originality/value: A selection on the following alternatives will be possible: a – don’t care the damage is not affecting the structure performance; b – repair is needed but will be sufficient; c – substitute the damaged component as soon as possible.

Innovative composite material component with embedded self-powered wireless sensor device for structural monitoring

An innovative structural component, manufactured in laminated composite material is provided of an embedded sensor device to monitor his temperature and transmit it via wireless radio connection. The aim of such component is both to supporting loads, as a common structure, and to sense at the same time one or more structural parameters of interest, as in example in this work the temperature, but that can be the state of stress and/or strain and/or the dynamic mechanical loading. This capability is achieved by mean of one or a plurality of sensors, wired to a processing unit. Such unit is linked to a remote control station via wireless radio connection to transmit the acquired data. The electronic equipment is powered by an embedded energy harvesting circuit that transduce the mechanical vibrations in electric power by mean of a piezoelectric element, allowing the device to work without an external power source or a battery. Sensor network, processing unit, radio device and energy harvester are designed in a flat scale with ultra-low power electronic components in order to be embedded inside the stacking sequence of the laminated composite material. The structure and the monitoring device are all in one. The solution can be part of a more complex hosting structure as sub-component or it can be the whole structure itself. A remote station collects and post-process the information of one or more of such components and evaluate the measured parameters. The advantage of this component is to be a completely autonomous system, all integrated, ready to use and free of external equipment that can be directly subjected to harsh environmental actions.

Evaluation of tribological properties of components of polymer composite selflubricating materials

The paper presents data on the anti-wear properties of the basic components of polymer self-lubricating composite materials for heavy loaded friction units. In friction these components are released from the composite structure as a result of destructive processes or physical desorption with increasing temperature and involved in the metal plating of friction parts. Besides, it shows the wear form of a sample friction pair in comparison with I-40 base oil, often applied as a composite plasticizer, on the example of synergistic interference of unhardened epoxy-diane resin with highly dispersed mineral fillers of the serpentine group. The conducted study reveals the ability of minerals to reduce the wear rate of a sample friction pair as a result of the transferred film formation. The kinetic features of model samples wear under special conditions for testing ceramic materials are determined as well. In addition, the paper identifies the practicability to exploit layered silicates in the structure of polymer matrices as lubricating agents of heavy loaded friction units.

Laser-induced cratering of a 3DCC material at mesoscale: Experiments and simulations

This study concerns the damaging of a 3-Dimension Carbon/Carbon (3DCC) composite material under dynamic loading. Experiments were performed with a laser facility delivering energies between 13 and 40 J with 100 nanoseconds pulse duration. The focal spot diameter was 250 μm, leading to dynamic pressure up to 10 GPa. The focal spot being smaller than the size of the composite components, it allows us to study the dynamic behaviour of the material at mesoscopic scale. The dynamic process of this cratering is then investigated via 3D numerical simulations, and a Johnson-Holmquist model is proposed. It appears that comparison of simulations with experimental results is useful to identify the dynamic strength of individual components of composite materials.

Boosting medical technological innovation through finite element simulation

Riba Composites, thanks to the experience gained through years of working with and sizing composite material components, was able to support and collaborate with 3Shape in the design of their new CBCT (Cone Beam Computed Tomography) scanner.

Study on Charcoal Sorbent Encapsulation in High-Molecular Compound during the Development of Filtering Personal Protective Equipment of Skin

Personal protective equipment (PPE) of skin, made of filtering materials is the most convenient equipment for work in the areas, contaminated with percutaneous toxic chemicals. These kinds of materials must contain activated charcoal on its surface, enough for safe exploitation of PPE. The main task of polymer component in composite filter protective material for PPE is to fix the activated charcoal on the material`s surface, to sorb toxic chemical and to transport it into sorbent`s macro- and mesopores. During the study on the penetrability of methyl salicylate – toxic chemical`s simulator – into such polymer materials, like polyurethane, polyvinyl chloride, polystyrene, styrene-butadiene-styrene polymer and polypropylene it was found out, that styrene-butadiene-styrene polymer possessed the highest sorptivity towards methyl salicylate. So there are good reasons to continue the studies on charcoal sorbent encapsulation in high-molecular compound during the development of filtering personal protective equipment of skin, with the use of styrene-butadiene-styrene polymer as a matrix

R&D of colloid components of composite material for fire prevention and extinguishing and an investigation of its performance

Abstract Because the existing fire prevention and extinguishing materials for coal mining cannot adhere to coal for long periods of time, this study investigated their colloid components. A colloid recipe of sodium silicate as the base material, sodium bicarbonate as the coagulation accelerator and sodium polyacrylate as the polymer additive was determined. An optimum proportion was obtained by orthogonal tests, whereby the ratio of water to solid was 4:1, sodium silicate accounted for 4%, sodium bicarbonate accounted for 5% and sodium polyacrylate accounted for 0.75‰. Comparing the performance of four other typical materials of fire prevention and extinguishing through contrast experiments, we observed that the new material has advantages of dropping the temperature, lowering the concentration of oxygen and carbon monoxide and increasing the concentration of carbon dioxide. In addition, a field test was conducted with the new material. After injection, three zones of spontaneous combustion showed clear changes: the oxidation temperature rise zone was ahead by 8 m, its length was shortened by 20 m and the choking zone moved up by 28 m. These changes indicated the improvement of colloid could significantly increase the effect of fire prevention and extinguishing materials.

Study of Influence of Composite Materials Components on Properties of Concrete Mixtures and Concrete in Time Dynamics

It is accepted to call concrete a special construction mix which consists of several main components – most often, these are cement, water and various fillers. As a result of grout hardening, the artificial stone, used in many areas where durability, stability and durability are required, is formed. To improve the main characteristics of concrete, various additives are added to the mix. These substances are also capable of accelerating the speed of construction and reducing the funds expenditure. It is especially important to apply additives at the installation of coverings to airfields, at the construction of moorings, roads, at the laying of pools or during other hydraulic engineering constructions, and also at the construction of monolithic industrial facilities and houses. The article deals with the composition and quantity of complex organomineral additives, the duration and conditions for the formation of composites’ structure.

Методы проектирования изделий из полимерных композиционных материалов

FIELD: composite materials. SUBSTANCE: invention relates to manufacturing composites, e. g. for slabs to protect rapidly-wearing surfaces of grooves passing loose materials or gas-dust stream conduits, etc. Method of invention, including preparation of mixture of components and filling of mold to form products, is distinguished by that, mixture of composite material components is prepared by pouring filler, heated to temperature above melting point of matrix metal, into molten matrix metal to give blend which is used to fill mold. EFFECT: enabled conduction of process in any atmosphere, including air, and obviated necessity of preheating mold when large-size products are molded.

Composite materials for impellers of the turbocharger of automotive engines

The aim of this work is the search and selection of components of composite materials are fully meeting the requirements imposed to the materials of the impellers of the turbocharger. During the work modern components of the composites and their properties is described. The requirements to materials of impellers were formulated. Patent search was carried out to describe existing concepts of impellers made of composite materials. A possible production version of the impellers is described, revealed their advantages and disadvantages. In the course of patent studies have not traditional the advantages of using composites in the design of the turbocharger. Described the possibility of creating a rotor of the electric machine of the compressor impeller by weaving a copper wire. The main technology of manufacture of impellers is described. Given domestic and foreign manufacturers of polymer matrixes and fibers. The described physic-mechanical properties of randomly reinforced composite materials available on the market today. A comparative analysis of selected composite material most fully meets the requirements - polyamideimide filled carbon fiber. The use of continuous fibers in the impellers is an effective way to increase the strength of the latter. It is established that as a cheaper alternative to polyamideimide can be a carbon-containing material '^^11!" provided reinforcement of the wheel with continuous fibers. Cheap and widely used materials (filled polyamides, polycarbonates, epoxy resin, etc.) can be used in the manufacture of impellers in centrifugal blowers with manual or electric drive. Composites with carbon fiber in silicon carbide matrix (C-SiC) can act as an alternative to heat-resistant nickel alloys, of which currently produce the turbine wheel.

Effect of the carbon component on the electrical and optical properties of nanocellulose-based composites

The results of X-ray studies of the structure of components of composite materials based on milled microcrystalline cellulose are presented. The 3D model of the atomic arrangement in the short-range order of amorphous carbon can be described by a mechanical mixture of two types of clusters in the ratio of 1 : 2. One type of clusters is formed by two planar graphene single layers shifted relative to each other and containing vacancies, and the other type is presented by six graphene grids. The cellulose matrix with silicon nanoparticles has a low photoluminescence-signal degradation rate. The introduction of fullerenes into nanomaterial as a third nanofraction, as well as the action of ozone, leads to anomalous luminescence kinetics under UV (ultraviolet) photoexcitation, which can be associated with competing processes of hydrogen and oxygen adsorption on the surface of silicon nanoparticles. A change in the ionic conductivity of the porous cellulose matrix upon exposure to ozone can be used to develop effective ozone detectors. Such a filler as amorphous-crystalline carbon causes not only ionic but also electronic conductivity in the sample; however, the processes of space-charge redistribution remain dependent only on the ion-current component. An increase in the total current passing through the pressed sample eliminates the need for a further increase in the signal in the design of ozone sensors.

Composite electrode materials for solid oxide fuel cells with the protonic electrolyte of La1 – x Sr x ScO3 – δ

Heterogeneous systems based on the proton–conducting oxide of La0.95Sr0.05ScO3 – δ with Cu, Fe, Ni, Pd, La0.9Sr0.1MnO3 – δ considered as potential materials of solid oxide fuel cell (SOFC) electrodes are synthesized. Chemical interaction between individual components of composite materials is studied, dependences of thermal and chemical expansion of the electrolyte and composites are obtained, conductivity of electrodes is measured under the conditions of SOFC operation.