Exploring the Use of Cork Based Composites for Aerospace Applications

2010 ◽  
Vol 636-637 ◽  
pp. 260-265 ◽  
Author(s):  
José M. Silva ◽  
Tessaleno C. Devezas ◽  
A. Silva ◽  
L. Gil ◽  
C. Nunes ◽  
...  
Keyword(s):  
Damage Tolerance ◽  
Matrix Material ◽  
High Strength ◽  
Experimental Tests ◽  
Dynamic Loads ◽  
Natural Material ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Different Types ◽  
The Matrix

Aerospace components are characterized by having high strength to weight ratios in order to obtain lightweight structures. Recently, different types of sandwich components using composite materials have been developed with the purpose of combining the effect of reinforced face-sheets with low weight core materials, such as honeycombs and foams. However, these materials must combine damage tolerance characteristics with high resistance under both static and dynamic loads. Cork composites can be considered as an alternative material for sandwich components since cork is a natural material with some remarkable properties, such as high damage tolerance to impact loads, good thermal and acoustic insulation capacities and excellent damping characteristics for the suppression of vibrations. The experiments carried out in this investigation were oriented in order to optimize the specific strength of cork based composites for sandwich components. Static bending tests were performed in order to characterize the mechanical strength of different types of cork agglomerates which were obtained considering distinct production variables. The ability to withstand dynamic loads was also evaluated from a set of impact tests using carbon-cork sandwich specimens. The results from experimental tests showed that cork agglomerates performance depends on the cork granulate size, the type of reinforcing elements and the bonding procedure used for the cohesion with the matrix material.

Investigation of Tensile Property of Aluminium SiC Metal Matrix Composite

2015 ◽  
Vol 766-767 ◽  
pp. 252-256 ◽  
Author(s):  
A. Siddique Ahmed Ghias ◽  
B. Vijaya Ramnath
Keyword(s):  
Composite Material ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Matrix Material ◽  
Chemical Properties ◽  
High Strength ◽  
Stir Casting ◽  
The Matrix ◽  
Hybrid Metal Matrix Composite

The composite material is a combination of two or more materials with different physical and chemical properties. The composite has superior characteristics than those individual components. A hybrid composite is the one which contains at least three materials. When the matrix material is a metal, the composite is termed as metal matrix composites (MMC). The MMC is a composite material with two constituent parts, one being a metal. The other material may be another metal, ceramic or fiber. Among all the MMC’s, Aluminium is the most widely used matrix material due to its light weight, high strength and hardness. This paper deals with the fabrication and mechanical investigation of hybrid metal matrix composite Al - SiC. The fabrication is done by stir casting by adding the required quantities of additives into the stirred molten Aluminium. The results show significant effect of mechanical properties such as tensile strength, yield stress and flexural strength. The internal structure of the composite is observed using Scanning electron microscope (SEM) and found that are formation of pores in them.

Simulation and Experimental Study of the Coupling Drive Magnetic Field for Embedded Giant Magnetostrictive Actuators

2012 ◽  
Vol 510 ◽  
pp. 322-327
Author(s):  
Bin Wang ◽  
Yi Jie Wu ◽  
Lei Zhang
Keyword(s):  
Magnetic Field ◽  
Matrix Material ◽  
Experimental Tests ◽  
High Frequencies ◽  
Output Displacement ◽  
Close Relationship ◽  
The Matrix ◽  
Magnetostrictive Actuators ◽  
Magnetostrictive Actuator ◽  
The Relationship

Embedded giant magnetostrictive actuator (EGMA) is one of the most important applications of magnetostrictive material. Giant magnetostrictive actuators can deliver big-output displacement and can be driven at high frequencies. These characteristics make them suitable for a variety of positioning. However, because of the limitation of structure, the drive coil and EGMA cannot be any size as needed, so how to maximize the displacement in the limitative situation by optimization becomes the key of design. Several methods are available in the literature, but the coupling drive magnetic field of EGMA and its matrix material is often ignored. In fact, there was a close relationship between the matrix material and the distribution of drive magnetic field. To analyze the relationship, this paper establishes the magnetic circuit model for EGMA. The simulation of the coupling drive magnetic field is also presented. Finally the assumption is validated through experimental tests carried out with two different matrix materials.

Mechanical Properties of Densified Untwisted Carbon Nanotube Yarn / Epoxy Composites

2015 ◽  
Author(s):  
Risa Yoshizaki ◽  
Kim Tae Sung ◽  
Atsushi Hosoi ◽  
Hiroyuki Kawada
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Polymer Matrix Composites ◽  
High Strength ◽  
Matrix Composites ◽  
Specific Strength ◽  
The Matrix ◽  
Cnt Arrays ◽  
Strength And Stiffness ◽  
Long Fibers

Carbon nanotubes (CNTs) have very high specific strength and stiffness. The excellent properties make it possible to enhance the mechanical properties of polymer matrix composites. However, it is difficult to use CNTs as the reinforcement of long fibers because of the limitation of CNT growth. In recent years, a method to spin yarns from CNT forests has developed. We have succeeded in manufacturing the unidirectional composites reinforced with the densified untwisted CNT yarns. The untwisted CNT yarns have been manufactured by drawing CNTs through a die from vertically aligned CNT arrays. In this study, the densified untwisted CNT yarns with a polymer treatment were fabricated. The tensile strength and the elastic modulus of the yarns were improved significantly by the treatment, and they were 1.9 GPa and 140 GPa, respectively. Moreover, the polymer treatment prevented the CNT yarns from swelling due to impregnation of the matrix resin. Finally, the high strength CNT yarn composites which have higher volume fraction than a conventional method were successfully fabricated.

scholarly journals Recent studies on particulate reinforced AZ91 magnesium composites fabricated by Stir casting – A review

2020 ◽  
Vol 4 (2) ◽  
pp. 115-126
Author(s):  
Anil K. Matta ◽  
Naga S. S. Koka ◽  
Sameer K. Devarakonda
Keyword(s):  
High Performance ◽  
Matrix Material ◽  
Weight Ratio ◽  
High Strength ◽  
Casting Process ◽  
Stir Casting ◽  
Critical Conditions ◽  
Matrix Composites ◽  
The Matrix ◽  
Magnesium Composites

Magnesium Metal Matrix Composites (Mg MMC) have been the focus of consideration by many researchers for the past few years. Many applications of Mg MMCs were evolved in less span of time in the automotive and aerospace sector to capture the benefit of high strength to weight ratio along with improved corrosion resistance. However, the performance of these materials in critical conditions is significantly influenced by several factors including the fabrication methods used for processing the composites. Most of the papers addressed all the manufacturing strategies of Mg MMC but no paper was recognized as a dedicated source for magnesium composites prepared through stir casting process. Since stir casting is the least expensive and most common process in the preparation of composites, this paper reviews particulate based Mg MMCs fabricated with stir casting technology. AZ91 series alloys are considered as the matrix material while the effect of different particle reinforcements, sizes , weight fractions on mechanical and tribological responses are elaborated in support with micro structural examinations. Technical difficulties and latest innovations happened during the last decade in making Mg MMCs as high performance material are also presented.

scholarly journals Interpretation of Specific Strength-Over-Resistivity Ratio in Cu Alloys

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7150
Author(s):  
Hongming Li ◽  
Shuang Zhang ◽  
Yajun Zhao ◽  
Xiaona Li ◽  
Fushi Jiang ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Lower Limit ◽  
High Strength ◽  
Alloy System ◽  
Resistivity Ratio ◽  
Specific Strength ◽  
Cu Alloys ◽  
The Matrix ◽  
In Series ◽  
Pure Cu

Reaching simultaneously high mechanical strength and low electrical resistivity is difficult as both properties are based on similar microstructural mechanisms. In our previous work, a new parameter, the tensile strength-over-electrical resistivity ratio, is proposed to evaluate the matching of the two properties in Cu alloys. A specific ratio of 310 × 108 MPa·Ω−1·m−1, independent of the alloy system and thermal history, is obtained from Cu-Ni-Mo alloys, which actually points to the lower limit of prevailing Cu alloys possessing high strength and low resistivity. The present paper explores the origin of this specific ratio by introducing the dual-phase mechanical model of composite materials, assuming that the precipitate particles are mechanically mixed in the Cu solid solution matrix. The strength and resistivity of an alloy are respectively in series and parallel connections to those of the matrix and the precipitate. After ideally matching the contributions from the matrix and the precipitate, the alloy should at least reach half of the resistivity of pure Cu, i.e., 50%IACS, which is the lower limit for industrially accepted highly conductive Cu alloys. Under this condition, the specific 310 ratio is related to the precipitate-over-matrix ratios for strength and resistivity, which are both two times those of pure Cu.

Self-Healing Materials as New Biologically Inspired Materials

2012 ◽  
Vol 16 ◽  
pp. 11-25
Author(s):  
Fabrizia Ghezzo ◽  
Xi Geng Miao
Keyword(s):  
Failure Mechanisms ◽  
Matrix Material ◽  
High Strength ◽  
Self Healing ◽  
Micro Cracks ◽  
Specific Objective ◽  
Wide Range ◽  
The Matrix ◽  
Safety And Reliability ◽  
Healing Agent

Lightweight, high strength fibre-reinforced polymeric composites are leading materials in many advanced applications including biomedical components. These materials offer the feasibility to incorporate multi functionalities due to their internal architecture, heterogeneity of materials and the flexibility of combining them using currently available fabrication methods. In spite of the excellent properties of these materials, their failure is still a questionable and not well predicted event. Delamination, debonding and micro-cracks are only some of the failure mechanisms that affect the matrices of polymer based composites. More complex cases exist with the combination of multiple failure mechanisms. In such cases a self-repairing mechanism that can be auto-triggered in the matrix material once the crack has been formed, would be very beneficial for all the applications of these materials, reducing maintenance costs and increasing their safety and reliability. Self-healing materials have been studied for more than a decade by now, with the specific objective of reducing the risks and costs of cracking and damage in a wide range of materials. Different approaches have been taken to create such materials, depending on the kind of material that needs to be repaired. The most popular methods developed for polymers and polymer reinforced composites are considered in this review. These methods include materials with micro-capsules containing a healing agent, and composites with matrices that can self-heal the cracks by repairing the broken molecular links upon external heating. While the first approach to healing has been widely used and studied in the past decade, in this review we focus on the second approach since less is reported in the literature and more difficult is the development of the materials based on such a method.

scholarly journals Mechanical Characteristics and Adhesion of Glass-Kevlar Hybrid Composites by Applying Different Ratios of Epoxy in Lamination

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 94
Author(s):  
Sajid Hussian Siyal ◽  
Subhan Ali Jogi ◽  
Salman Muhammadi ◽  
Zubair Ahmed Laghari ◽  
Sadam Ali Khichi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Bonding Strength ◽  
Hybrid Composites ◽  
Matrix Material ◽  
Tensile Modulus ◽  
Experimental Tests ◽  
Material System ◽  
Swelling Ratio ◽  
Specific Strength

Hybrid composites have great potential for specific strength and specific stiffness, effective in aerospace industries, submarines, and light-weight automotives. The mechanical strength and adhesiveness of hybrid laminates can be enhanced by effective use of matrix materials in different ratios of epoxy resin and epoxy hardener. Gentle use of resin and hardener in the fabrication of hybrid composites can alter tensile modulus, the bonding strength between matrix and fabric. Spectacular progress has been achieved by the selection of appropriate amounts of resin and hardener in the hybridization of composite laminate. Hybridization was made by Kevlar inorganic/organic fabrics and glass fabrics stacked with epoxy matrix material. To achieve the combination of mechanical properties and bonding strength, transparent epoxy resin and hardener of commercial grades mixed in various ratios are incorporated as matrix material to fabricate laminate. Three different sheets, named A (3:2), B (4:1), and C (2:3), were embedded by the hand layup method to prepare a hybrid composite. Experimental tests, according to ASTM 3039, were performed to determine the tensile mechanical properties. Peel tests, according to ASTM 6862-11, were performed to investigate the interlaminar strength between Kevlar and glass layers. Shore A and Shore C hardness durometers were used to find out the hardness of the specimens at different spots using the ASTM D-2240 standard. Finally, physical testing, such as density and then water absorption, was carried out using the ASTM D-570 standard to check the swelling ratio of the different specimens. The results obtained highlight that the specimen of the glass/Kevlar hybrid embedded in the ratio 3:2 in lamination has the best mechanical properties (tensile strength and hardness) and the lowest swelling ratio, while the material system in the ratio 4:1 shows the best interlaminar properties and adhesion capabilities.

Measurement of microscopic displacements in graphite/epoxy composite materials using a SEM-generated surface map

1990 ◽  
Vol 48 (4) ◽  
pp. 430-431
Author(s):  
R.C. Burghardt ◽  
J.M. Ehrman ◽  
T.C. Stephens ◽  
M.F. Hibbs
Keyword(s):  
Composite Materials ◽  
Resin Composite ◽  
Matrix Material ◽  
Crack Tip ◽  
High Strength ◽  
Beam Current ◽  
Experimental Conditions ◽  
X Ray ◽  
The Matrix ◽  
Sporting Goods

Graphite fiber-reinforced resin composite materials have a wide use in aerospace, automotive and sporting goods applications where high strength to weight ratios are requisite. Many of these materials use highly cross-linked epoxy resins as the matrix material. Unfortunately these resins have a low resistance to crack propagation and as a result research efforts have been directed towards reducing this tendency.The ability to measure microscopic displacements and calculate strain fields in the vicinity of a fracture crack tip under experimental conditions was needed in order to help predict the fracture resistance of various composite materials being tested. A technique was developed that made it possible to derive displacement measurements on a micrometer scale in the region of a crack tip from observations of epoxy-based composites being fractured using a tensile stage equipped scanning electron microscope (SEM). Samples were polished on the surface to be observed and sputter coated with 5 to 10 nanometers of either gold or 60:40 gold-palladium prior to mounting on the TS-2 tensile stage of a JEOL JSM-35CF. This instrument was also equipped with a Krisel beam interceptor, a beam current meter, a Tracor Northern TN-2000 x-ray analyzer and a TN-1310 digital beam control system. Using the digital beam and x-ray mapping capabilities a matrix of small dots was “written” onto the surface of the sample as shown in figure 1.

The fabrication and neutron shielding property of polyphenylene sulfide containing salicylic acid/Gd2O3 composites

2021 ◽  
pp. 095400832110214
Author(s):  
Yumin He ◽  
Pengcheng Li ◽  
Haohao Ren ◽  
Xi Zhang ◽  
Xiulian Chen ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Salicylic Acid ◽  
Thermal Property ◽  
High Strength ◽  
Polyphenylene Sulfide ◽  
Nano Particles ◽  
Neutron Shielding ◽  
Aerospace Applications ◽  
Blending Method ◽  
The Matrix

A series of neutron absorbing materials with good neutron absorbing capacity, high strength and good thermal property were designed and prepared in this work. First of all, polyphenylene sulfide containing different mole content of salicylic acid (SAPPS) in the main chain was synthesized by nucleophilic substitution polymerization under high pressure. Then the composites with different content of nano Gd2O3 and modified PPS were prepared by melt blending method. The testing results indicated that the copolymers SAPPS were synthesized successfully, there was an interface interaction between nano Gd2O3 and the matrix without the need for surfactants or coupling agents. Additionally, the content of nano Gd2O3 had no obvious influence on the thermal property of the composites. While following with the increase of the content of nano Gd2O3, the tensile strength of the composites increased firstly and then decreased, when the content of nano Gd2O3 was 10 wt%, the tensile strength of 10%Gd2O3/5%SAPPS reached the maximum value of 74.9 MPa. The results of neutron shielding testing indicated that the content of nano-particles had a large effect on the neutron shielding rate of composites. The neutron shielding rate of 50%Gd2O3/5%SAPPS composite was up to 83%. All of these results indicated that the Gd2O3/5%SAPPS had potential to be applied to the high-temperature resistance and thermal shielding materials in nuclear and aerospace applications.

scholarly journals Graphene oxide/mussel foot protein composites for high-strength and ultra-tough thin films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Eugene Kim ◽  
Xuyan Qin ◽  
James B. Qiao ◽  
Qingqing Zeng ◽  
John D. Fortner ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Matrix Material ◽  
High Strength ◽  
Organic Polymer ◽  
Material Synthesis ◽  
Synthesis Strategy ◽  
The Matrix ◽  
Facile Fabrication ◽  
Mussel Foot Protein ◽  
Film Composites

Abstract Graphene oxide (GO)-based composite materials have become widely popular in many applications due to the attractive properties of GO, such as high strength and high electrical conductivity at the nanoscale. Most current GO composites use organic polymer as the matrix material and thus, their synthesis suffers from the use of organic solvents or surfactants, which raise environmental and energy-consumption concerns. Inspired by mussel foot proteins (Mfp) secreted by the saltwater mussel, Mytilus galloprovincialis and by recent advances in microbial protein production, we developed an aqueous-based green synthesis strategy for preparing GO/Mfp film composites. These GO/Mfp films display high tensile strength (134–158 MPa), stretchability (~ 26% elongation), and high toughness (20–24 MJ/m3), beyond the capabilities of many existing GO composites. Renewable production of Mfp proteins and the facile fabrication process described provides a new avenue for composite material synthesis, while the unique combination of mechanical properties of GO/Mfp films will be attractive for a range of applications.

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