Advanced Materials Research Vol. 576

Abstract: Zinc Oxide (ZnO) films were prepared on unheated glass substrate by radio frequency (RF) magnetron sputtering technique and post deposition annealing of the ZnO thin film were performed at 350, 400, 450 and 500°C. Post annealing temperature was found to improve the structural and electrical characteristics of the deposited films. The structural properties of the films were carried out by the surface profiler, X-Ray diffraction (XRD), atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) while the electrical properties were measured using current voltage (I-V) probe measurement system. All samples exhibit the (002) peak and the sample annealed at 500°C gives the highest crystalline quality, highest Rms roughness (1.819 nm) and highest electrical conductivity (3.28 x 10-3 Sm-1).

Abstract: The optically transparent conducting molybdenum doped indium oxide (IMO) thin films were deposited on glass substrates by sol-gel spin coating technique. The effect of various molybdenum contents in the range of 0.25–1 at.% on the structural, morphological, optical and electrical properties was studied. XRD results confirmed the formation of cubic bixbyite structure of In2O3 with preferred orientation along (222) plane. Microstructural studies show nearly spherical morphology for thin films with size in the range of 20-40 nm. The films doped with 0.25 at.% Mo found to exhibit a minimum electrical resistivity of 188×10-3 Ω.cm and an average optical transmittance of more than 80% in the visible region with a band gap of 3.85 eV.

Abstract: Amorphous carbon thin films have been deposited by a simple Thermal Chemical Vapor Deposition (CVD) with varying the amount of natural precursor (camphor oil) onto the glass substrates. In this work, we have investigated the effect of different amount of camphor oil on the evolution of electrical conductivity and the optical and structural properties of amorphous carbon thin films. The amorphous carbon thin films were characterized by using current-voltage (I-V) measurement, UV-VIS-NIR spectroscopy and Raman spectroscopy. The current-voltage (I-V) study reveals that the highest electrical conductivity was deposited at 3 ml camphor oil. The optical band gap is almost unchanged with the increase of camphor oil amount. Raman result indicates that amorphous carbon thin films consists a mixture of sp2 and sp3 bonded carbon atoms.

Abstract: The fundamental study on carbonization characteristic of low rank coal under low temperature was investigated by using a laboratorium scale electric furnace. In this experiment, the mass decreasing fraction of coal during carbonization, the bahaviour of volatile matter and the changes of fixed carbon as well as gas composition during carbonization was carried out. The effect of fixed carbon content in fuel on iron quality is also investigated. The experimental method for investigation of low rank coal carbonization characteristic was selected by variation of the carbonization temperature and nitrogen was introduced as a carrier gas. The experimental result shows that the mass decreasing fraction of coke was increased with the carbonization period. The fixed carbon content in coke was increased with the carbonization temperature. The gas composition during carbonisation shows consist of argon (Ar), carbon monoxide (CO) and methane (CH4). It shows that the CO gas is dominated of the amoung them. It is shown that the iron surface hardness may affect on carburizing media.

Abstract: Little information has been known on the initial – stage oxidation if there is water vapor involved. Cr samples of 10 mm × 10 mm × 1 mm were isothermally oxidized in dry and wet environment respectively for 86.4 ks. Compact and even surface of Cr2O3 was formed on samples oxidized in dry environment. However, the ability to form compact and even Cr2O3 was retarded in wet environment. XRD analysis on all samples shows that Cr2O3 can be formed in dry and wet environment. The IR transmission spectra for samples oxidized in dry environment, were consisting of more intense peak while samples oxidized in wet environment has more relaxed peak. Moreover the peak of samples oxidized in dry tends to be narrower, while samples oxidized in wet tend to have broader peak.

Abstract: Solid state polymer electrolyte blend of polyethylene oxide, chitosan, ammonium iodide, and iodine crystals has been prepared by solution cast technique. The highest ionic conductivity of the polymer electrolyte was 1.18 × 10−5 S cm−1 at room temperature. Addition of chitosan to the electrolyte has improved its mechanical properties. A photovoltaic junction with configuration ITO/TiO2-solid state polymer blend electrolyte/ITO has been constructed. The open circuit voltage Voc, short circuit current density Jsc, and fill factor FF% obtained from the photovoltaic system under white light illumination of 100W Tungsten lamp are 320-350 mV, 0.59-2.5μAcm-2 and 42%-59% respectively.

Abstract: Pretreatment on tungsten carbide (WC-Co) surface is critical for obtaining perfectly adherent diamond coatings by chemical vapor deposition (CVD). The carbide surface should have high roughness to facilitate diamond nucleation and adhesion. The presence of cobalt—common binder for tungsten carbide—on the surface to be coated should be made minimum since it has negative influence on the diamond deposition process. In this study, surface pretreatment on tungsten carbide using sulfuric acid was evaluated in terms of the resulted cobalt removal and the surface roughening. The variables included were acid concentration, reaction temperature, and reaction time. The resulted surface roughness was 29% higher than initial, averaged at 1.07 µm. The acid pretreatment was also found effective in eliminating surface cobalt.

Abstract: The important of Reverse Engineering (RE) and Rapid Prototyping (RP) process in the automotive sector has made the knowledge of its operation vital to engineers and designers. The purpose of this research is to apply and implement the RE and RP process and also integrate advance quality tools in the development of automotive components. The advance quality tools that been implemented are Quality Function Deployment (QFD) and Failure Mode Effect Analysis (FMEA). To produce the final products, a machine that works under Fused Deposition Modeling (FDM) principle is used. A manual window crank as the automotive component has been selected as the product for this paper and application. Before continuing the fabrication of product, the design improvement of the target product to a better product level is done through the QFD and FMEA as the advance quality tools. The analysis from QFD and FMEA tool is then translated into the design and product development.

Abstract: Additive Manufacturing technologies are widely employed in the production of models for a range of industries. However, to-date little explicit research attention has examined the way in which the Laser Sintering technologies can be used in the specific application of architectural models. To evaluate the suitability of the process, this research develops a SWOT analysis of the Laser Sintering technologies for this application, highlighting not only the current advantages and disadvantages, but also future opportunities and threats which can be observed. From this assessment, the paper demonstrates the use of LS through the implementation of a four-stage model, supported by two examples of commercially produced architectural models.

Abstract: The environment seems to have an effect on Acrylonitrile-Butadiene-Styrene (ABS) which consequently causes physical, morphological and thermal stability changes to the polymer. Not only that, these changes may have caused nozzle blockage on the liquefier of the Fused Deposition Modeling (FDM) rapid prototyping machine. Experiments are conducted to support and verify whether ABS does affect the blockage. It has been observed that physical changes may have not caused nozzle clogging.