Advanced Materials Research Vol. 795

Abstract: Polypropylene (PP)/Acrylonitrile butadiene rubber (NBRr)/rice husk powder (RHP) composites was fabricated with silane and acetic anhydride treatment agent. The in-situ formed RHP filled PP/NBRr composites were prepared by melt mixing technique using Haake internal mixer at 180 °C. The tensile properties of the both treatment methods were invesigated with Instron mechanical analysis. The results indicated that acetic anhydride treatment was found to exhibit better mechanical properties for RHP filled PP/NBRr composites. Good compatibility and stronger interaction between anhydride moieties with PP/NBRr was resulted.

Abstract: Varying amount of recycled-Aluminum (0, 3.0, 3.5 and 4.0 wt.% re-Al) particulates produced from aluminium beverage cans were successfully reincorporated into Sn-0.7Cu base matrix solder material via powder metallurgy technique. This paper focuses on the mechanical properties aspect of the new solder when joint on Cu-substrate. The hardness of the composite solders sintered bulks was enhanced with the increasing re-Al additions. Moreover, the composite solders have shown enhancement of shear stress strength at the solder joints. Fracture surface of the failure samples were analyzed using scanning electron microscope (SEM) which have indicated all samples failed under ductile fracture mechanism. However, with the refining dimples formation shown on the fractograph, this report suggests the increasing re-Al reinforcement has optimized the solder joints ductility strength.

Abstract: Composite approach in lead-free solder development was perceived as an expectation in finding new robust solder. Accordingly, Sn-0.7Cu/re-Al composite lead-free solder with varying amount of recycled-Aluminum (0, 3.0, 3.5 and 4.0 wt.% re-Al) particulates produced from aluminum beverage cans were successfully fabricated via powder metallurgy techniques in this study. This paper focuses on the thermal properties focusing on the melting temperature of the new developed Sn-0.7Cu/re-Al lead-free composite solder. The melting temperature (T_m) of the new solders was determined using differential scanning calorimetry (DSC). The melting temperature of the composite solders has showed comparable results with the monolithic solders of Sn-0.7Cu lead-free solder.

Abstract: A coal fired power plant with its normal operation temperature of 540oC in which its steam trap bypass tube in that power plant was totally fractured. The aim of this study is to explore the evidence related to the steam trap bypass tube failure and to determine the failure mechanism and the root cause of the failure and to give an appropriate recommendation. From the evidence with considering the contribution factors such as temperature, pressure and environment, a fault analysis was made and it can be concluded that the cause of failure to the steam trap bypass is due to multi causes which consists of creep failure and hydrogen damage.

Abstract: Microfluidic devices present a powerful platform for working with living cells and even gases. Parameter such as the length and volume scales of these devices in miniaturize system makes it possible to develops and perform detailed analyses with several advantages. The objective of this project is to do a design of 1μm microfluidic separator device that consist the microchannel. Furthermore, another objective is to understand the fundamental physical processes of fluid flow in these devices and to predict their behavior and every method using in the simulation of COMSOL Multiphysics 3.5 software will be elaborate in numerical simulation technique section. Finally, result from the simulation such as concentration, fluidic flow pressure and velocity field will be observed and explained in the result section.

Abstract: The effect of preparation conditions, temperature and atmosphere, on oxygen stoichiometry and interlayer cation mixing in the layered rock salt material LiNi_0.8Mn_0.1Co_0.1O_2-δ has been investigated using X-Ray powder diffraction, including Rietveld refinement. Interlayer mixing occurs as a direct consequence of oxygen deficiency; samples with least oxygen deficiency and most cation order were obtained on firing in O₂ at ~ 900 950C.

Abstract: The corrosion behavior of anodized powder metallurgy Al/2wt%Mg composites reinforced with the short fibre alumina Saffil^TM was studied using potentiodynamic polarization in 3.5% NaCl solutions. The materials under investigation were fabricated using powder metallurgy route. Anodising process has been done to the materials to improve their corrosion resistance. Anodising process were carried out in sulphuric acid solutions with different anodizing voltage, which are 10V, 12V, 14V, 16V and 18V and different concentration of sulphuric acid (5%, 10%, 15%, 20% and 25%). Results from Tafel plot showed that corrosion behavior of PM Al-Mg composites strongly depends on the anodizing parameters. Corrosion resistance increases with the increase in anodizing voltage and concentration of sulphuric acid. The maximum corrosion resistance was recorded by the PM Al-Mg composite anodized using 16V and in the 15% concentration of sulphuric acid.

Abstract: Catastrophic failure is often associated with a large temperature rise. This situation may lead to a drastic deterioration in material strength where a cooling system is important for a smooth system plant operation to prevent catastrophic failure to its equipments, parts or processes. In this study, a part of a failed closed recirculation system water cooling pipe in a steel manufacturing plant in Malaysia has been investigated for detailed failure analysis. A steam leakage of a water cooling pipe with a closed recirculation system operation made of ASTM A106/A (Carbon Steel Pipes for high temp service) was detected. The aim of this study is to explore the evidence related to the water cooling pipe leakage and to investigate the cause of failure. Detailed investigation was carried out by visual inspection, optical microscopy and hardness testing. With the evidence obtained, due to presence of water scale and prolonged overheating, decarburization had occurred. During decarburization, it was found that carbon elements from inner surface tube had depleted through the outer tube surface. The accumulation of carbon elements on the outer tube surface appears to show significantly higher brittle zone in the outer tube and with the presence of tensile stress developed from operating thermal cycle which subsequently resulted in crack. It can be concluded that the water cooling pipe leakage was due to thermal fatigue.

Abstract: This paper discussed refinement strategy that been used to reveal crystallographic properties of lithium-based complex oxides with layered rock salt structure. Rietveld analysis using XRD data was used to determine the amount of interlayer mixing and estimate oxygen contents. The structural model and refinement methodology was controlled and validated initially using a standard sample. Thus, this paper summarized structure refinement strategy that been used to quantify the degree of cation order associated with interlayer mixing and investigate the sensitivity of laboratory XRD data to oxygen non-stoichiometry that recently published elsewhere [.

Abstract: The titanium dioxide (TiO₂) is a semiconductor oxide photocatalys, which is chemically and biologically inert but exhibits excellent photolytic activity in the ultraviolet (UV) region. Progress in photocatalytic water disinfection requires understanding both concepts of TiO₂ semiconductor as well the biochemistry of microorganisms. The advantage and disadvantage for current water purifications are discussed. Finally, the photocatalytic reactions to water disinfection and detoxification using solar energy.