Key Engineering Materials Vol. 908

Abstract: X-ray reflectivity technique is applied in evaluation of deposition of multilayer thin film fabrication process. Amorphous silicon carlbide (SiC) and carbon (rGO) was deposited alternatively on a glass substrate. Via X-ray reflectivity, every layer deposited can be analyzed, thus every flaws in defected layer can be figure out. This paper will explain further throughout the evaluation process. Deposition process carried out by radio frequency (RF) magnetron sputtering of 99% purity of silicon carbide (SiC) and carbon (C) as a target. Implementation of X-ray reflectivity technique had proven in fabricating better quality of thin film.

Abstract: The characteristics of sputtered amorphous diamond-like carbon-containing copper (DLC: Cu films) films deposited on Si (100) substrates and Si (111) in argon gas-filled chamber using carbon target under different substrates deposition time, and RF power. The samples were deposited by RF magnetron sputtering and analyzed using Raman spectroscopy and X-ray reflectivity (XRR) methods. Different parameters of depositions were used to study the structure, thickness, roughness, and density of the samples. The Cu preliminary layer act as a catalyst to growth the DLC thin-film analyzed using XRR analysis to measure thickness, roughness, and density of the thin films. The film structures of the samples were analyzed using Raman spectroscopy with a 532nm laser source. Gaussian peak shapes were used in Raman spectrum fitting to analyzed to measure the D band and G band for both samples. The Films thickness, roughness, and mass density were studied by XRR techniques using XRD to acquire the multilayer structure of thin films grown by magnetron sputtering.

Abstract: This work reports the synthesis of rGO using magnetron sputtering followed by the annealing process in argon. Raman mapping analysis helped confirm the existence of D, G and 2D band after annealing which indicating the formation of rGO and not a monolayer of graphene. Out of plane XRD measurement observed 21.5°, 30.1° and 35.5° corresponding to d-spacing and 0.412 nm, 0.296 nm and 0.253 nm respectively and for in plane XRD measurement are observed at are 2θ peaks at 30.1°, 35.5° and 62.4° corresponding to d-spacing 0.296 nm ,0.253 nm and 0.148 nm respectively. All the spectrum shows shifted due to the presence of defect in the deposited rGO structure. Thus, the in plane measurement are successfully demonstrated as an alternative method to evaluate the thin rGO film.

Abstract: Solid oxide fuel cell has become one of the interest in the sustainable energy field. In order to improve the efficiency of a solid oxide fuel cell (SOFC), the interconnect must be coated with a protective coating of (MnCO)₃O₄ spinel coated stainless steel. Commercial manganese cobalt (MnCO)₃O₄ was used as a protective coating on ferritic stainless steel in this study using the electrophoretic deposition (EPD) coating technique. This article examines the impact of voltage deposition towards morphological characteristics. The goals of these studies are to find the best interconnect coating parameter while experimenting with voltage deposition. The spinel coated interconnect (MnCO)₃O₄ was studied using Elemental Energy Dispersive X-ray Spectroscopy (EDS). The surface morphology and coating thickness are examined using a Scanning Electron Microscope (SEM). X-ray diffraction (XRD) is used to determine the phase of the spinel coated interconnect. The EPD coating technique for (MnCO)₃O₄ spinel coated interconnect is carried out in an aqueous suspension with 30V and 40V with coating durations of 20s, 30s, 40s, 50s, and 60s. By observing the deposition morphology and thickness coating at 30V and 40V, the best covering parameter for interconnect is 30V, 40s which fulfil the interconnect requirement.

Abstract: Plasma transfer arc welding (PTAW) has been one of the popular methods for depositing thick hard facing. In this study, this method was used to lay the nickel hard-facing without tungsten carbide and with different compositions which are 35 wt%, 50 wt% and 60 wt% carbides. The hard facing was characterised using a scanning electron microscope with EDS and x-ray diffractometer (XRD). The corrosion behaviour was evaluated using three electrodes electrochemical test with saturated calmonel electrode (SCE) and platinum plate as the reference electrode and counter electrode respectively. The corrosion test shows that the hard facing had higher corrosion resistance in an alkaline environment compared to an acidic environment. The corrosion mechanism was by the dissolution of the nickel matrix, Ni₃B dissolution is seen in an acidic environment while in alkaline electrolyte, the dendritic nickel dissolves preferentially.

Abstract: Zinc Oxide (ZnO) nanostructured was synthesized by green method. The zinc acetate dehydrated, Zn (CH3COO)2.2H2O was mixing with psidium guajava leaves extract as reducing as well as capping agent which is very simple, rapid, cost-effective and environment friendly route. However, Titanium Dioxide (TiO₂) sol-gel was synthesized by using titanium (IV) butoxide, Ti (OC4H9)4, butanol, C₄H₉OH, acetic acid, CH₃COOH, and distilled water, H₂O. The deposition of ZnO/TiO₂ thin films on the glass substrate applied by spin coating method. The calcination temperature has been used for the first layer of ZnO were 400 °C, 500 °C, 600 °C and for the second layers, which is TiO₂, were 500 °C and 600 °C. Four types of characterization were perform to analyse the ZnO/TiO₂ thin films such as X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and Atomic Force Microscopy (AFM). From XRD analysis, the result shows the zincite structure of ZnO thin films and the anatase structure of TiO₂ thin films. Besides, increasing the calcination temperature will increase the peak intensity. Furthermore, FESEM performed to analyse the surface morphology of ZnO/TiO₂ thin films, which is when calcination temperature increase will increase the size of the particles. Meanwhile, the analyzing of ZnO/TiO₂ thin film using AFM shows that with increasing the calcination temperature will increase the surface roughness and particle size. The UV-Vis was use to determine the optical properties of the ZnO/TiO₂ thin films where it shows the percentage transmittance improved after increase calcination temperature.

Abstract: High corrosion resistance of Zn-Al-Mg (ZAM) alloy is widely used in steel wire rope protection. This alloy, however, due to Mg reactivity, easily induced dross formation containing MgZn2 and Mg2Zn11 which reduced the coating integrity. Thus, in this work, Mg is replaced with various wt.% Sb (ZAS) coated on steel surface will via hot-dip process at the eutectic environment. The thickness of the intermetallic layer and coating thickness were observed using an optical microscope and SEM. It was found that 0.3 wt.% Sb improved the corrosion performance 45.5% (0.00267 mmpy) than ZAM coated steel (0.00490 mmpy) under accelerated corrosive medium of 3.5% NaCl.

Abstract: Microorganisms can initiate, accelerate, and/or inhibit corrosion processes through several different ways, including modification of the localized environment at the metal/solution interface causing pitting attack. In this work, the effect of pH on Pseudomonas growth was investigated in understanding the biodeterioration manganese steel rod due to bacteria attack. This study focused on identifying the effect of pH on the corrosion of galvanized steel. In artificial seawater containing Pseudomonas Aeruginosa. Galvanized steels were exposed to the medium for 7 days at 37°C at pH ranging from 5.0 to 9.0. Roles of different metallurgical, chemical and microbiological features on the surface will be reviewed to interpret this phenomenon. The results confirmed that the pits formed in this case are attributed to the Pseudomonas Aeruginosa sp under microbial corrosion.

Abstract: An attempt is made in this work to improve the performance and tool life of the tungsten carbide (WC) coated aluminium chromium nitride (AlCrN) via physical vapor deposition (PVD) method. Various deposition temperatures ranging from 250, 350, 400, and 450 oC were investigated to evaluate the characteristic of coated carbide. Prior to the deposition process, WC surfaces were treated in Murakami’s solution for 15 minutes followed by Caro’s solution for 10 seconds to improve the coating adhesion on WC by the dissolution of cobalt (C); roughened the carbide surface. The thickness of the coated AlCrN increases proportional with higher deposition temperatures (from 1.14 μm to 2.18 μm) and homogenously coated. While XRD analysis observed the presence of AlN and CrN phases attributed to AlCrN coating. The hardness of the coated carbide was highest at 450 oC deposition temperature (1325 HV). The qualitative scratch test following ASTM D 3363 indicated that higher temperature (400 oC and above) provides good adhesion characteristics between AlCrN coating and WC.

Abstract: Copper-tin-zinc (Cu-Sn-Zn) ternary alloy coatings was successfully deposited from a less hazardous electrolyte containing copper (II) chloride, tin (II) chloride, zinc chloride, sodium hypophosphite and complexing agent. In this work, the impact of different complexing agent on morphology, chemical composition, current efficiency, microhardness, and corrosion rate were investigated by method of SEM equipped with EDX spectroscopy, weight gain measurements, XRD, Vickers microhardness test and potentiodynamic polarization measurement, respectively. It was discovered that, Cu-Sn-Zn alloys prepared using sodium formate shows the highest microhardness value. It is also can be concluded that, complexing agent have a significant impact on the appearance and the surface morphology of the Cu-Sn-Zn alloy electrodeposits.