Papers by Keyword: Tensile

Abstract: The dispersion and exfoliation of graphene oxides in polymer matrix remains a challenge for graphene oxides based epoxy nanocomposites fabrication. In the present paper, we reported a simple and facile solvent exchange technique to successfully transfer graphene oxides (GOs) from aqueous solution to ethanol. In addition, we found that GO dispersion in epoxy resins was affected by the curing agents. Good dispersion of GOs in epoxy resin together with enhanced thermal and mechanical properties were observed when epoxy was cured with aliphatic curing agents. For aromatic curing agent, high loading of GOs leaded to GOs aggregation, but well dispersed GOs was observed at low loading of GOs. Especially, a 12 °C increase of glass transition temperature of the epoxy resin was observed with only 0.1 wt% GOs was added to the epoxy resin.

Abstract: 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.

Abstract: Tensile, flexural and impact strength are considered as main criteria to determine the mechanical properties of any materials. These properties were determined for woven banana and glass fiber, reinforced epoxy composites. The hand-lay method of fabrication was employed in preparing the composites. Natural fibers offer both cost savings and reduction in density as well as environmental friendly when compare to glass fibers. As if the strength of natural fibers is not as remarkable as glass, fibers its specific properties are comparable.

Abstract: This paper investigates the effect of nanoclay content on glass fibre reinforced polymer (GFRP) composites under tensile and flexural loading. Four different combinations of GFRP composite panels made of fiber glass/nanomodified polyester resin have been prepared by hand lay-up manufacturing technique (HL). Composite samples are tested for tensile and flexural properties. Scanning Electron Microscopy (SEM) has given morphological picture of the FRP fracture samples. The results showed that the tensile and flexural strength is greatly increased over the range of nanoclay loading by about 23% and 40% respectively.

Abstract: The aluminium based composites are increasingly being used in the transport, aerospace, marine, automobile and mineral processing industries. The widely used reinforcing materials for these composites are silicon carbide, aluminium oxide and graphite in the form of particles or whiskers. In this study Al6061-6 & 4wt% Al₂O₃ based metal matrix composite were produced by mechanical stir casting process. The obtained cast metal matrix composite is carefully machined to prepare the test specimens for hardness, tensile as well as fracture toughness studies as per ASTM standards. The hardness, tensile strength and fracture toughness properties of Al6061-Al₂O₃ composites are explored experimentally. Finally compare the material characterization with heat treatment process sample and compare the fracture toughness of sample with mathematical approach, experimental and finite element method.

Abstract: This study focuses on tensile properties and impact strength of coir fibre reinforced polypropylene composites under influences of fibre loading and various temperatures conditions. All samples were fabricated by using hot-press technique. Tensile and izod impact samples were prepared in accordance to the standard specifications as closely as possible. Three different ratios of fibre with matrix which were 10%, 20% and 30% were studied. The results revealed that 20% volume fraction of coir fibre demonstrated optimum tensile and impact properties. Significance reduction of impact strength under low temperature condition had been shown for all composites due to the brittleness of both fibre and matrix.

Abstract: "New materials" as they are called composite materials are designed with special features to meet some special requirements regarding: mechanical strength and rigidity, resistance to corrosion, resistance to chemical agents, low weight, dimensional stability, resistance to varying loads, shock and wear, insulating properties and aesthetics. The main advantage of these materials is the high ratio between strength and weight density. This paper deals with the tests of a composite materials as polypropylene (PP) materials, firstly as pure and recovered polypropylene materials, and secondly, the same materials with the addition of 5%, 10%, 15%, 20%, 25% Reogard 2000®. This study led to the conclusion that the best mechanical properties of polypropylene is for 20% concentration of Reogard2000®.

Abstract: The current work deals with the tensile and flexural properties of bamboo fiber/epoxy composites. Tensile and flexural property evaluations were carried out in accordance with the ASTM D638 and ASTM D790 standards, respectively. Bamboo fiber was obtained from local bamboo by means of degumming process. The matrix being used is Eposchon general purpose Bisphenol A-epichlorohydrin epoxy resin mixed with Eposchon general purpose Polyaminoamide epoxy hardener supplied by P.T. Justus Kimiaraya. The specimens were cut from five bamboo fiber/epoxy composite panels. Five different fiber volume fractions, V_f, i.e. 0, 10, 20, 30 and 40 vol%, have been considered. All mechanical and physical characterization were carried out at the Mechanical Engineering laboratory, Universitas Muhammaiyah Yogyakarta. Photo macrographs of selected samples were analyzed to describe their failure modes. Physical property evaluation revealed that a slight fiber content deviation from their expected results was observed. Whilst tensile strength, modulus and strain to failure, as well as flexural strength and modulus were found to increase with the increase of fiber content up to 29.8%, maximum flexural strain to failure was being at V_f = 21.1%. Tensile specimens were mostly failed by debonding followed by fiber breakage, while flexural specimens were mostly failed by debonding followed by fiber breakage and fiber pull-out at tension sides.

Abstract: Natural fibres are preferred compared to synthetic fibres because of several advantages such as biodegradable, lightweight, low cost and good mechanical properties. Roselle is one of the plants found to be suitable to be used to produce natural fibres. Although natural fiber reinforced composites are becoming widely used, several weaknesses such as lack of good interfacial adhesion, low melting point and poor resistance to moisture absorption are harmful to its further acceptance. Chemical treatment is a method that can improve the interfacial bonding, stop water absorption, clean the fibre and increase surface roughness. In this study, roselle fibres were immersed in Sodium hydroxide (NaOH) with 3 different concentration (3, 6, and 9%). The results before and after treatment were compared. Scanning electron microscope was used to examine the surface morphology. Tensile properties of roselle fibre were performed to study the tensile properties. Results shows that the higher concentration of NaOH will increase the surface roughness and have higher ability to clean the fibre. For tensile properties, 6% of NaOH give the highest tensile strength. It can be concluded that, 6% of NaOH is the most suitable concentration to clean roselle fibre and while maintaining good tensile properties.

Abstract: The effects of mechanical properties (tensile properties and resilience test) and morphology of recycled nitrile glove (NBRr) filled epoxidized natural rubbers (ENR25) were examined. Two different size ranges of NBRr particles, i.e., S₁ (250μm-500μm) and S₂(2cm-5cm) were used in this study. The NBRr/ENR25 compounds with five different compositions of NBRr (5, 15, 25, 35 and 50 phr) were prepared using a two roll-mill at room temperature. The result indicated that the tensile properties such as tensile strength and elongation at break decreased as the ratio of NBRr increased. Meanwhile stress at 100% elongation show an increasing trend with the addition of recycled nitrile glove in ENR25. The resilience properties of NBRr/ENR25 compounds decreased when NBRr loading increased. The scanning electron microscopy studies showed that the fine size, S₁ of NBRr particles in NBRr/ENR25 compounds illustrated a better NBRr-ENR25 matrix interaction compared with coarse size, S₂ of NBRr particles. The results overall indicated that the NBRr/ENR25 with fine size, S₁ of NBRrparticles show better mechanical properties (tensile properties and resilience properties) and morphology compared to coarse size, S₂ of NBRr particles.