Abstract: This study represents the result of hybrid cathodic protection (Hybrid CP) system application. Hybrid CP, which is the combination between sacrificial anode cathodic protection (SACP) system and impressed current cathodic protection (ICCP) system, can be optimum way to protect corrosion, especially in concrete columns. In this study, sections below a water line, i.e. submerged and tidal zones, were cathodically protected by means of SACP. In addition, ICCP was applied to the upper areas of water line, i.e. splash and atmospheric zones. Water level was changed to verify the effectiveness of hybrid CP system. The test factors were natural, CP, and 4-hour depolarization potential.
Abstract: More than a billion rubber tires are discarded annually around the world. Growing piles of discarded tires create fire and environmental hazards. Current disposal methods are mostly wasteful and costly. Tires possess high tensile strength, are chemically very stable, practically non-destructible and light in weight. All of these properties make tires a potentially useful geo-material. This paper presents the results of an extensive laboratory testing study investigating the potential of using shredded tires mixed with sandy soils (rubber-sand) as lightweight fill and backfill material in road construction. The results show that rubber-sand has significant promise for use as an earthwork fill material. In addition to its engineering benefits, such use of scrap tires would significantly contribute to solving the ever-growing tire disposal problem.
Abstract: Keywords: Boron Carbide; Silisium Carbide; Composite; Powder Metallurgy. Abstract : In this study, effect of boron carbide (B4C), aluminium oxide (Al2O3) and silisium carbide (SiC) addition on microstructure and mechanical properties of diamond cutting segments was investigated. The effects of reinforcement particle additions on characteristic of CuSn matrix composites have been investigated. For this purpose, Al2O3, SiC and B4C addition quantity was added as 2 wt.%. Samples of segments were processed by cold pressing at 550 MPa, followed by sintering at 850°C/30min. Micro-structural aspects were observed by optical microscope. Density, hardness and wear tests were also performed. Wear behaviour and hardness values of segments changed depending on aluminium oxide, silisium carbide and boron carbide addition. The alloy CuSn– 2 wt.%. B4C presented the best results, available for use in cutting tools.
Abstract: The present work aims to compare the mechanical properties of Polypropylene (PP) based composites reinforced with B4C. Maleic Anhydride Modified Polypropylene (MAPP) was added to improve the B4C-matrix interphase. Processing has been carried out by twin-screw extrusion and injection molding. By adding the B4C particles to the PP and PP+MAPP matrix, the yield strength, shore D hardness, microhardness and relative scratch resistance increased gradually, but PP+MAPP/B4C composites showed better overall mechanical properties than the PP/B4C composites. However, elongation at break values occurred for all composites dropped with the B4C content, and PP+MAPP/B4C composites exhibited lower elongations at break than PP/B4C composites.
Abstract: Al2124-20wt.% SiCp composites were prepared by powder metallurgy (PM) method and investigated the tribological behavior of MMCs. S/N ratio analysis and analysis of variance (ANOVA) were employed to investigate which design parameters significantly affected the wear of the composites. The hardness of the matrix alloy increased from 44.2 HRB up to 87 HRB when reinforced with SiC particles. The ANOVA results showed that the hardness exerted the greatest effect on the wear, followed by the abrasive size.
Abstract: The effects of boron carbide (B4C) additions on characteristic of diamond impregnated Fe-Co-Cu matrix composites have been investigated using powder metallurgy (PM) method. For this purpose, samples of Fe-(30-60)wt. % Cu–20 wt. %Co alloys and1wt. % B4C additions of its matrix were processed by cold pressing at 350 MPa, followed by sintering at 1100°C. Microstructural examination, hardness and wear tests were performed.The microstructure of Fe–Cu–Co alloys was very sensitive to the Cu content and pore closure took place with increasing the Cu content.In addition, the addition of B4C particles increased Fe–Cu-Co hardness about 44% compared to samples without B4C particles. The experimental results showed that alloy Fe–60 wt. % Cu–20 wt. %Co-1 wt. % B4C presented the best results for use in diamond cutting tools.
Abstract: Glass fiber reinforced polymeric (GFRP) composite laminates have been prepared by hand layup method. According to ASTM standard, the test specimens have been prepared to carry out the flexural bending tests. The specimens have been subjected to both cyclic impact load and cyclic gradual load with various frequencies prior to the flexural bending analysis. Three point bend method has been adopted to find out the flexural strength and flexural modulus. Flexural strength and modulus have been calculated from the load deflection curve obtained from the tensometer for respective specimens. The flexural bending properties of GFRP composites subjected to cyclic gradual load and cyclic impact have been compared and found that the GFRP composite materials are effective for gradual cyclic load than the cyclic impact load.
Abstract: Dynamic consolidation is the route that can be used as a processing method to produce aluminum-matrix composite. This process offers several unique advantages over the static compaction methods in conventional powder metallurgy. Al-20vol.% SiCp composites were manufactured by direct explosive compaction with various explosive pad thicknesses that resulted in densities of compacts from 92% to 98.5% TD. The wear behavior of the various compacts was evaluated using a pin-on-disc wear tester. The microstructure characterization was performed using light microscopy. The dominant wear mechanisms were evaluated using scanning electron microscopy. The results showed that the sliding wear resistance increased with the increase in the density of the compact composites.
Abstract: Friction is classified as the main dominant element having an adverse influence on materials' lifespan and performance. Friction between any sliding contacts is continually accompanied by heat generation and shear force. The surface deterioration produces destruction in the component and reduced the life expectancy of the components. The shear force and/or the frictional heat areseen to be the main reasonscausing occurrence of the wear on surfaces and the wear removal during adhesion wear loading. In the current paper, a comprehensive experiments and observation were made to correlate the three main elements of tribology (friction, temperature, and weight loss) to epoxy and its composites based on glass and kenaf fibres. The tests were conducted in adhesive wear loading conditions against stainless steel counterface under dry contact conditions. SEM was performed to categorize the damage features of both composites. The results revealed that the interface temperature has more influence on the wear behaviour of both composites than the friction coefficient. Different destructive features were observed.