Materials Science Forum Vol. 1068

Abstract: This work aims to investigate the structural deterioration of the Carbon Fiber Reinforced Epoxy (CFRE) composite under vibration loading by monitoring the variation of the electrical resistance of the composite. The vacuum assisted resin transfer moulding process is used to fabricate the CFRE composites. Multiwall Carbon Nanotubes (MWCNTs) (0.5% wt) are added to the non-conductive resin to increase its electrical conductivity before CFRE fabrication. The tests were carried out by monitoring the variation in electrical resistance of the CFRE composite at 90 Hz frequency vibration loading. The dispersion of MWCNTs into the matrix and the damage of CFRE composite are illustrated by the SEM images. The results show that the electrical resistance change can be considered as a good indication to detect damage in CFRE (modified with 0.5 wt % MWCNTs) under vibration loading.

Abstract: The glass fiber reinforced plastic (GFRP) composite materials are widely used in industries; these composites are coupled into large structures by drilled holes. In the present investigation, the characteristics of such drilled holes and defects were studied using GFRP composite samples with open-hole (at different positions), half-through holes and epoxy filled holes under three-point bend loading conditions. The “composite with epoxy filled holes” envisages maximum flexural strength, "composite with holes at a depth of 2.5 mm" showed intermediate and "composite with an open hole" exhibited minimum flexural strength. However, the flexural strength of the "composite" was increased when the relative distance between the holes was increased. The hypothesis of investigating the effect of defects in the form of Teflon exhibited significant results. The flexural strength was minimum in the case of multiple defects, however, it showed maximum fracture toughness. It was also observed that if the defect is present only at one end, it exhibited maximum flexural strength and minimum fracture toughness value.

Abstract: Fused Deposition Modeling (FDM) 3D printing is one of the most popular 3D printing technology today and its products is always interested to improving their mechanical properties by printed engineering parameters. In this study, the influences of infill density and printing pattern on mechanical properties of FDM 3D printing structure have been studied on some common printing materials including Acrylonitrile Butadiene Styrene (ABS), Polylactic Acid (PLA), carbon fibre reinforced PLA composites (PLA-CF). Each material is printed with different patterns such as hexagonal, square, triangular, zigzag structures at 15% infill. Particularly for the triangle printed structure of ABS, there are three infill densities at 15 %, 25 % and 40 %. The experimental process has evaluated the strength and deformation of the printing patterns. The results have shown that the influence of printing patterns on compressive strength are significant because of the relationship between printing patterns and sample weight. Besides, infill density also have a great influence on the compressive strength of 3D printed products.

Abstract: Metal matrix composites are the novel engineering materials finding applications in several extreme environmental and industrial requirements leading to the developments of numerous types of its kind in recent decades. Powder metallurgical techniques is one among the promising methods of producing intricate shaped end products out of the MMCs. Essentially the uniformity in distribution of the reinforcements and the accuracy in employing the percentile addition of the reinforcements decide the tailor made properties of these composites. There are several techniques to evaluate the reinforcement percentage and uniformity. This work concentrates on the analysis of effectiveness of volume fraction determination methods namely Archimedes test and acid dissolution test for 7075 Al/Al₂O₃ composite. Using the two methods the volume fraction of 7075Al/ Al₂O₃ composite prepared by powder metallurgy technique is determined. Advantages and disadvantages of both methods were analyzed using the result analysis and the observation indicated that the acid dissolution test produces more accurate results than the Archimedes test. In addition, the randomized selection of the specimens out of the end products leads to the corroboration of reinforcement uniformity in the composite matrix.

Abstract: Composites have a wide range of applications in the field of robotics, aerospace, aviation, sports, and automotive engineering. They have appealing properties such as high strength to weight ratio, good mechanical and electrical properties, and durability. Multilayered composites are prepared by stacking different layers of composites along different directions. This research focuses on the compression and tension response of multilayered composite panels without interference of bending by using in-plane loading. The aim of this research is to develop a generalized MATLAB code for a number of layers, to solve a model composite through analytical and MATLAB computations, to analyze the stress behavior in ANSYS (ACP) and finally to compare the results. For carrying out the analysis, a multi-layered, symmetric composite panel is modelled under in-plane loading. First, a mathematical model is formulized to solve the multi-layered composite panel under in-plane loading and analytical results are obtained. Next, a generic MATLAB code is developed, followed by simulations and computational study using ANSYS (ACP) module. The results of MATLAB and the solution of the mathematical model are found to be identical. Further, the results obtained from ANSYS (ACP) have shown the stresses in each layer and overall deformation of the composite panel. The overall results from three methods have shown that the stresses produced in a composite panel are symmetric across mirrored layers. However, there is a significant difference between the analytical and ANSYS (ACP) results, this is due to the limitations of the Classical Laminate Theory (CLT) which has been used in the analytical study. CLT does not take into effect the out-of-plane stresses. However, in real life scenarios, out-of-plane stresses exist under the in-plane loadings and have a significant effect around the edges and corners of the panel. If 10 percent of the edges are removed on both sides, the analytical results and simulations are found to be in good agreement. Further, after the ANSYS (ACP) analysis has been obtained for the panel, a sandwiched composite panel has been modelled by adding a core material of foam and polyethylene at the center of the composite. The thickness of the core material is varied to observe the change in the stress behavior. The results have shown that there is an increased stress behavior when a softer core is used or the thickness of the core material is increased.

Abstract: The Portland cement has showed a negative impacts to the environmental and therefore researchers from all over the world are interested in using wastes and their recovered extraction processes to discover fresh construction materials. The present review manuscript is an attempt to reconsider the use of abandoned computer / electronic wastes, also known as E-waste, which is used as alternative materials for the development of a variety of non-toxic concrete for the industrial and construction sectors. The main goal of this review is to provide current position of concrete materials for this reason, it is necessary for understanding these modern, complicated, valuable, but hazardous wastes. These materials are used as alternate for crude aggregate in building material production. The brand-new, cutting-edge, and ground-breaking concept are used for the production of environmentally friendly, cost-effective green concretes. Furthermore, chemical, physical, and metallurgical reuse procedures for E-waste, as well as its benefits and dis-advantage with heat, tensile, the endurance characteristics for Electronic-wastes such as green concretes, unsafe compound, are appraised. This research also examines the application glass as E-waste from cathode rays are used in concrete, mortar, and cement paste. The E-waste materials are used as bituminous mixture. The "Urban Mining" strategies have recognized the application of non-biodegradable materials recovered as E-waste plastics as a partial substitute for natural courses or fine components. This review paper assists to promote the implementation of green precast E-waste in the construction sector in a sustainable and cost-effective manner, it also impasse the exhaustion of natural resources, environmental contamination in earth and underground water. It also concern over the environmental pollution and to defend the health of living organisms.

Abstract: To meet future social and environmental objectives for diagnosis of human diseases has offered to develop the proficient gas sensors devices with higher selectivity and sensitivity. For the production of ZnO doped reduced graphene oxide (ZnO doped rGO) nanocomposite, a one-pot hydrothermal approach. The morphological, structural and composition of nanocomposite were investigated to confirm ZnO nanoparticle effectively doped on rGO nanosheets. The nanocomposite has exhibited a superior acetone sensing characteristics. Furthermore, the nanocomposite has a high selectivity for acetone vapour. These findings emphasise advantageous synergistic effects among ZnO and excellent rGO sheet substrate properties.

Abstract: A growing demand for advanced composite materials as well as diverse design requirements offering significant weight savings in comparison to conventional materials have all contributed to a growing interest in composite materials. This review paper is focused on Powder Metallurgy (P/M) process to fabricate magnesium based metal matrix composites. The excellent oxidation and corrosion resistance and low density of Silicon carbide have made it a popular material even at very high temperatures. Despite their very high specific strength, magnesium matrix composites possess excellent cast ability, good damping capabilities, and greater machinability. Therefore, this review paper discusses the importance, fabrication, and properties of magnesium matrix composite materials for industry applications. An examination of the properties of recently produced magnesium matrix composites by various researchers is presented in this review paper.

Abstract: Several parameters are required to improve Tire dynamic performances like high wet and dry traction (Grip), high wear resistance and high steering performance (handling). These performances depend on the physical properties of tire tread compound, tire construction, tread profile and road conditions. The most influential one is the reinforcing filler, which is responsible for inheriting the tread dynamic properties. Conventionally, carbon black is used as filler but it possesses a major hitch of CO₂ emission during manufacturing as well as in service conditions. Its high rolling resistance is responsible for boosting the carbon footprint of a vehicle. In the past few decades, the focus has been shifting on silica fillers, an emerging technology to develop low rolling resistance tires resulting in low CO₂ emissions thus contributing in the establishment of a healthy eco system. Design of Experiment (DOE) approach is used therefore, sixteen (16) variants of silica based compounds were prepared and properties of silica based samples were compared with that of carbon black compounds (conventional). The results revealed that this emerging silica filler showed promising results in giving the highest possible wet traction and lowest rolling resistance to minimize CO₂ (Greenhouse gas) in the environment.