Advanced Materials Research Vol. 845

Abstract: The laminated rubber-metal spring is well known in application as the vibration isolator for earthquake protection. The spring is therefore designed to be able to sustain the vibration waves from horizontal direction. This paper discusses the possibility of the laminated spring to be employed for other applications where the excitation mainly comes from axial direction, such as to isolate vibration transmission from heavy engine. The model is first developed for a simple finite rod to simulate the effect of internal resonances at high frequency when the wavelength is much smaller than the length of the rod. The effect of metal plates inserted in the rubber is then modelled using the lumped parameter system. The results are presented in terms of the vibration transmissibility.

Abstract: Fe-Ni-Cr or known as Incoloy 800H and Haynes HR120 is a solid solution strengthened iron-nickel based superalloy which is extensively used in high temperature and corrosive environment. The effect of grain size in creep strength and creep rate comes through the grain boundary sliding and grain boundaries as barrier mechanism. This paper describes the effect of microstructural variation of Fe-Ni-Cr on the high temperature creep properties. The materials were heat treated at temperature 1050°C and 1200°C followed by water quenching process. The grain size of the samples of Incoloy 800H is 95.47μm for as-received, 122.81μm for solution treated at 1050°C and 380.95μm for solution treated at 1200°C. And the grain size of the samples of Haynes HR120 is 53.45μm for as-received, 61.50μm for solution treated at 1050°C and 158.27μm for solution treated at 1200°C. The creep damage investigation was carried out in the three different grain sizes of Fe-Ni-Cr superalloy at 900°C with stress at 100MPa. Rectangular section forms of specimens are used in the research. In all the tests conducted, the creep curves show primary, secondary and tertiary stages. The creep fracture surface were characterised by using scanning electron microscope. It was found that larger grain size results in lower creep rate for alloy Haynes HR120 but inverse result showed on alloy Incoloy 800H.

Abstract: The isothermal oxidation behavior of two different grain size of Fe-33Ni-19Cr alloys was investigated at 700 °C in laboratory air. Different grain size of alloyed was made of solution annealing treatment at different temperatures, namely, 1050 °C and 1150 °C for fine and coarse grain, respectively. Optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were employed in this study to analyze the oxidation behavior of solution-annealed samples. Results indicate that the fine grain size solution-annealed alloys possess a better oxidation resistance and reduced oxidation rate than the coarse grain. The differences observed are attributed to the finer grains increasing the relaxation of the oxide scale stress and improving the adhesion of the oxide layer on the matrix.

Abstract: Crude palm oil (CPO) is one of the vegetable oil that has potential for use as a fuel in diesel engine. Despite years of improvement attempts, the high viscosity and the major chemically bound oxygen component in the biodiesel fuel play as a key element during combustion process. Purpose of this study is to explore how significant the effect of preheated biodiesel blends on the engine performance and emission. The blending of biodiesel was varied from 5vol%(B5)~ 45vol%(B45) and preheated fuel temperature from 40°C~60°C. The engine speed was varied from 1500 rpm~3000 rpm and the load test conditions of 100% are considered. The performances parameter study of diesel engine in brake power, torque and flywheel torque are described together with the emissions parameter such as opacity, hydrocarbon (HC), nitrogen oxide (NOx), carbon oxide (CO), carbon dioxide (CO₂) and oxygen (O₂). Under high load condition, preheated biodiesel blends were found enhancing the combustion process, resulting in better performances. Increased preheated fuel temperature, higher in torque value and brake power increases significantly as the engine speed increases.

Abstract: NOx and PM are the major product results from the combustion of diesel either in internal combustion engine or external burner system. Thus, the emulsification concept from diesel and water were studied with focusing in controlling of combustion process in order to minimize the harmful emission. The main purpose of this research is to investigate the effects of diesel-water emulsification on mixture formation, burning process and flame development in burner system. The studied parameters include equivalent ratio, water content in diesel-water emulsification and spray characteristics such as spray penetration length, spray angle and spray area. The spray image of different diesel-water ratio and equivalence ratio can be investigated by direct photography method with a digital camera. The real spray images with the time changes was analyzed and compared with based diesel fuel. The results show that the higher of water contents due to higher viscosity influences the higher penetration length and lower spray angle thus predominantly the lower combustible mixture and lower the flame penetration.

Abstract: Simple analytical model of plate dynamics usually applies for rectangular plate with simply supported edges. Analytical model of sound radiation from rectangular plate is also convenient, but not for other geometries and other boundary conditions. This paper presents a hybrid mathematical model which combines a semi-analytical model with the Finite Element Analysis (FEA) method to determine sound radiation from a vibrating structure. The latter is employed to calculate the vibration velocity of a structure with a rather complex geometry. The results are then used as the input in the semi-analytical model to calculate the radiated sound pressure through the Rayleigh integral. Results from the proposed model are presented here for the radiation efficiency of rectangular plates with different boundary conditions.

Abstract: The electronic packaging industry is now being driven towards smaller, lighter, and thinner electronic products but with higher performance and more functions. Thus, smaller solder ball sizes are needed for fine solder joint interconnections to fulfill these requirements. This study investigates the interfacial reactions during reflow soldering and isothermal aging between Sn-4.0Ag-0.5Cu (SAC405) and electroless nickel (boron)/ immersion palladium/immersion gold (EN(B)EPIG). Reliability of solder joint has also been investigated by performing solid state isothermal aging at 125 °C for up to 2000 hours. The results revealed that after reflow soldering, (Cu, Ni)₆Sn₅ IMC is formed between solder and substrate while after aging treatment another IMC was found between (Cu, Ni)₆Sn₅ and substrate known as (Ni, Cu)₃Sn_4. Aging time of solder joints resulted in an increase in IMC thickness and a change in morphology into more spherical, dense and with larger grain size. By using optical microscope, the average thickness of the intermetallics was measured and it found that the larger solder balls produced thicker IMC than the smaller solder balls during reflow soldering. However, after aging the smaller solders produced thicker IMC than the larger solders.

Abstract: This paper attempts to explain the motion behaviour of the marine riser coupled to a drill string when the vortex induced vibration (VIV) is involved. Vibrations have been reported to have a major effect on the drilling performance, affecting the rate of penetration (ROP), causing severe damages to the drilling tools and also reduces the efficiency of the drilling process. There are two major components of drilling tools that are subjected to vibration, namely the marine riser and the drilling string. Analysis of vibration in the marine riser and drill string are two topical areas that have individually received considerable attention by researchers in the past. Though these two subjects are interrelated, borne by the fact that the marine riser encapsulates and protects the drill pipe, there have been few attempts to investigate them together as a unity. Due to the complexities of the models, simplified assumptions were made in order to undertake the investigation by using staggered approach. The results were compared with the experimental and simulation data from the open literature. It was found that the maximum displacement with negative damping occurs at low frequency and rotation speed.

Abstract: The laminated rubber-metal spring has been widely applied for earthquake vibration isolation which deals mainly for horizontal motion at a very low frequency input. This article presents the effect of a vertical vibration input, which is also aimed at applying the laminated spring for high frequency excitation. Static analysis is discussed here using the Finite Element Analysis (FEA) to observe the stress and strain distribution as well as the safety factor of the isolator due to the axial force. Solid rubber spring experiences greater deformation while it reduces for the laminated rubber-metal spring as more plates are embedded in the rubber. However, higher stress distributions occur on spring with multiple plates compared to solid rubber and the stress concentrate on steel plate layers. Strain distribution was observed to be high at solid rubber spring and it is decreasing on the laminated rubber-metal spring. The critical part for the strain distribution in the laminated rubber-metal spring is in the rubber layers.

Abstract: In this paper, the basic synthesis of encapsulated zeolite, polyaniline and zeolite/polyaniline composite as self-healing core materials for antifouling coatings was studied through interfacial polymerization. All materials were synthesized by using ammonium persulphate as an oxidant agent. Field Emission Scanning electron microscope (FESEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) techniques were used to characterize the synthesized materials. This paper aims to study on synthesis and characterization of zeolite, polyaniline and zeolite/polyaniline composite as self-healing core materials for antifouling applications. FESEM revealed that a smooth and homogeneous microstructure of materials. XRD results showed the high crystalline nature of all materials. FTIR showed the successful synthesis of the three materials. Finally, DSC results revealed appreciable Thermal properties of the developed materials.