62 research outputs found

    Effect of carbon nanotubes loading in multifiller polymer composite as bipolar plate for PEM fuel cell

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    In this study, bipolar plates for Proton Exchange Membrane Fuel Cell (PEMFC) were developed by compression molding technique using Polypropylene (PP) as a polymer matrix and Graphite (G), Carbon Black (CB) and Carbon Nanotube (CNTs) as reinforcements. United Stated Department of Energy (US DOE) target values were taken as the benchmark for the development and investigation of the bipolar plate properties. The effects of CNTs loading on the electrical and mechanical properties of G/CB/PP composite were investigated. By adding small amount of CNTs such as 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 wt% into G/CB/PP composite thus will give synergy effects on electrical conductivity and mechanical properties. It was found that, using CNTs as a third filler at a loading of 6 wt% in a G/CB/PP composite, shown the higher result of in-plane electrical conductivity is 158.32 S/cm, the density and shore hardness 1.64 g/cm3 and 81.5 (SH) respectively. Meanwhile, the optimum value of flexural strength obtained was 29.86 MPa at 5 wt% of CNTs

    Effect of Carbon Nanotubes on Properties of Graphite/Carbon Black/Polypropylene Nanocomposites

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    Abstract. High chemical corrosion, low manufacturing cost and light of total mass of bipolar plate in Proton Exchange Membrane Fuel Cell (PEMFC) lead most of the PEMFC’s researchers over the world attracted their interest to replace pure graphite or metal based bipolar plate with conductive polymer composites (CPCs) bipolar plate. CPCs is fabricate from the mixed of conductive fillers such as and Graphite (G) andCarbon Black (CB) had been incorporated in Polypropylene (PP) matrix for fabrication of electrical conductive polymer composite plate. Most researchers reported only at high loading of fillers (more than 90 wt.%), are gave electrical conductivity above 100 S/cm, which is target from Department of Energy (USA). Higher loading of fillers cause change in rheological properties and increase the difficulties in polymer processing. Thus will decreasing the electrical and mechanical properties of CPCs as bipolar plate. Therefore, in this study carbon nanotubes (CNTs) which have 1000 time electrical conductivity than copper wire are introduced into G/CB/PP composite to compensate above problems. But the main problems of CNTs, at high loading it tend to agglomerate and thus will affect the properties of CPCs. So that, small amount of CNTs which is 0.2, 0.4, 0.6 and 0.8 wt.% will be added into G/CB/PP composite. But weight percentage of CB and PP has been fixed which is 25 wt.% and 20 wt.% respectively and the weight percentage of G will various from 55 wt.% to 54.2 wt.% according to CNTs loading. The result shows that the G/CB/CNTs/PP composite with 0.2 wt% CNTs has the higher electrical conductivity 295.78 S/cm

    Failure Analysis of Hybrid Fibre Reinforced Plastics for Bolted Joint under Thermal Effect

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    Composite material is gaining a large attention in these few years due to its high strength to weight ratio. The cost of composite is also relatively lower than conventional metallic alloy. Several previous studies had shown introducing of synthetic fibre in the natural fibre-based composite polymer can enhance the mechanical strength of the composite structure. This research paper studies the effect of temperature and preload moment on the bearing strength of woven kenaf-glass fibre reinforced polypropylene hybrid composite. The kenaf fibre and E-glass fibre are in the form of plain weave fabric. Composite specimens were manufactured through hot press moulding compression method at 180ºC. In bolted joint test, specimens were exposed to a temperature of 25ºC (room temperature), 40ºC, 50ºC, and 60ºC and tightened with 0Nm, 5.2Nm and 7.5Nm preload moment. Bearing response under different conditions was tested according to ASTM D5961 standard procedure and failure modes were observed. The results revealed that increase in the ambient temperature reduced the bolted joint strength whereas the increase in preload moment improved the joint strength

    Failure analysis of two serial holes bolted joint hybrid composite

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    This study investigates the effect of different geometry parameters to the behavior of bolted-joint hybrid composites. The hot compression method is used to fabricate the hybrid composite. The composites were fabricated with three layers of woven fibers which are two layers of woven glass fiber and a layer of woven kenaf fiber with polypropylene matrix making a composite panel. The nominal thickness of these composites is 3mm and the bearing test is done by using Universal Testing Machine. The test were conducted according to ASTM D5961. The results show the different geometry parameters affect the behavior of hybrid composites

    Failure analysis on hybrid fiber reinforced plastics for bolted joint under geometric parameters effect

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    In this study, glass fiber and kenaf reinforced thermoplastic hybrid composite were fabricated using compression method. The composite is layout in sandwich structure. Woven glass fiber is sandwiched in between woven kenaf fiber with polypropylene matrix. The nominal thickness of the composite is 3mm. Bolted joint test was conducted according to ASTM D5961 using Universal testing machine. The results confirm geometric parameters affect the failure mode

    Proceeding Of Mechanical Engineering Research Day 2015 (MERD’15)

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    This Open Access e-Proceeding contains 74 selected papers from the Mechanical Engineering Research Day 2015 (MERD’15) event, which is held in Kampus Teknologi, Universiti Teknikal Malaysia Melaka (UTeM) - Melaka, Malaysia, on 31 March 2015. The theme chosen for this event is ‘Pioneering Future Discovery’. The response for MERD’15 is overwhelming as the technical committees have received more than 90 papers from various areas of mechanical engineering. From the total number of submissions, the technical committees have selected 74 papers to be included in this proceeding. The selected papers are grouped into 12 categories: Advanced Materials Processing; Automotive Engineering; Computational Modeling and Analysis & CAD/CAE; Energy Management & Fuels and Lubricants; Hydraulics and Pneumatics & Mechanical Control; Mechanical Design and Optimization; Noise, Vibration and Harshness; Non-Destructive Testing & Structural Mechanics; Surface Engineering and Coatings; Others Related Topic. With the large number of submissions from the researchers in other faculties, the event has achieved its main objective which is to bring together educators, researchers and practitioners to share their findings and perhaps sustaining the research culture in the university. The topics of MERD’15 are based on a combination of advanced research methodologies, application technologies and review approaches. As the editor-in-chief, we would like to express our gratitude to the editorial board members for their tireless effort in compiling and reviewing the selected papers for this proceeding. We would also like to extend our great appreciation to the members of the Publication Committee and Secretariat for their excellent cooperation in preparing the proceedings of MERD’15

    EFFECT OF AGING TREATMENT ON THE MICROSTRUCTURES AND HARDNESS OF Fe-Ni-Cr SUPERALLOY

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    Aging treatment was conducted on Fe-Ni-Cr superalloy to observe its effect on the microstructures and hardness of the material. Solution treatments were carried out at 900oC, 975oC, 1050oC, and 1125oC followed by water quenching. The samples were further treated with a double aging treatment at 720oC and 650oC for 4 hours and 12 hours respectively. Materials characterization techniques such as SEM, XRD, and optical microscopy were used to analyze the heat-treated samples. The Fe-Ni-Cr superalloy formed mainly a dendritic austenitic structure with Cr23C6 precipitated along the grain boundaries. Increase in solution treatment temperature results in dissolution of chromium carbide, coarser grain, and lower hardness for non-aged samples. Double aging treatment produced more chromium carbide, higher hardness, but no apparent change in grain size. Neither quenching nor aging treatments caused any phase transformation. The highest hardness value of 220.4 Hv was recorded for the sample solution treated at 1125oC for 2 hours and water quenched, followed by 2-step aging at temperature 720oC and 650oC for 4 hours and 12 hours respectively, and air cooled

    A Study on the Mechanical and Forming Performance of Oil Palm Fiber Reinforced Polypropylene Composite

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    Composite materials have steadily gained recognition worldwide for its uses in various sectors such as aerospace, infrastructures and automotive industries. Natural fibers are gaining recognition as a substitute to synthetic fibers due to its recyclability and abundance. Palm fiber reinforced polypropylene composite panels have potential to be stamp formed in order to build complex geometries. In stamp forming the most sensitive feature is elastic recovery during unloading. This phenomenon will affect the net dimension of the final product. Objective: To identify the effects of forming rate, tool radius, temperature and ratio of fiber to polypropylene on the spring-back of palm fiber composite. To deduce an empirical model in predicting spring-back. To investigate the effect of fiber composition on its tensile strength. Results: Statistical analysis conducted shows all the studied parameters gives significant effect towards spring-back. The higher the temperature, feed rate and fiber composition (up to 30wt %) the smaller the spring-back and it is vice versa for tool radius. An empirical model was formulated to predict the spring-back angle. 30wt% of fiber composition was found to give the highest tensile strength. Conclusion: The suggested temperature, fiber composition, tool radius and feed rate to get the smallest spring-back angle in the current study are 150 °C, 30wt%, 2mm and 500mm/min. While the fiber composition of 30wt% shows the highest tensile strength

    Effect of formation temperature on properties of graphite/stannum composite for bipolar plate

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    Bipolar plates are key components in Proton Exchange Membrane (PEM) fuel cells. They carry current away from the cell and withstand the clamping force of the stack assembly. Therefore, PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical strength, in addition to being light weight and low cost in terms of both applicable materials and production methods. In this research, the raw materials used to fabricate the high performance bipolar plate are Graphite (Gr), Stannum (Sn) and Polypropylene (PP). All materials used was in powder form and Gr and Sn act as fillers and the PP acts as binder. The ratio of fillers (Gr/Sn) and binder (PP) was fixed at 80:20. For the multi-conductive filler, small amount of Sn, which is 10 up to 20wt% (from the total weight of fillers 80%) have been added into Gr/Sn/PP composite. The fillers were mixed by using the ball mill machine. The second stage of mixing process between the mixer of fillers and binder is also carried out by using ball mill machine before the compaction process by the hot press machine. The effect of formation temperatures (160°C-170°C) on the properties of Gr/Sn/PP composite had been studied in detail, especially the electrical conductivity, bulk density, hardness and microstructure analysis of Gr/Sn/PP composite. The result shows that there are significant improvement in the electrical conductivity and bulk density, which are exceeding the US-DoE target with the maximum value of 265.35 S/cm and 1.682g/cm3 respectively

    Mechanical properties of polypropylene composites reinforced with alkaline treated pineapple leaf fibre from Josapine cultivar

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    This study investigates the mechanical properties of high impact polypropylene composite reinforced with pineapple leaf fibre from the Josapine cultivar as a function of fibre loading. PLF was extracted by using a pineapple leaf fibre machine and then an alkaline treatment was conducted to enhance the properties. Samples of the composite were fabricated with 100 mm fibre length with five different fibre loadings of PLF (30, 40, 50, 60 and 70 wt%). The fabrication was made by a compression moulding technique with unidirectional fibre orientation. Related tests such as tensile, hardness and density tests were conducted to determine the effect of fibre loading. The experimental data showed that the composite with the 60 wt% fibre loading offered the highest value of tensile strength, which was about 309%, and the Young’s modulus was about 540% compared to 0 wt% of PLF loading. Meanwhile, the hardness and density of the PLF/PP composites showed very similar values, with small increments from 30 wt% up to 70 wt% PLF loading compared to 0 wt% of PLF loading. The highest values are 65.38 Shore-D and 1.002 g/cm³ respectively. The results also revealed that PLF from the Josapine cultivar with alkaline treatment greatly influences the mechanical properties of PLF/PP composite
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