ORCID Profile
0000-0003-4995-4553
Current Organisations
University of Wollongong
,
Universiti Kebangsaan Malaysia
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Publisher: Elsevier BV
Date: 12-2012
Publisher: Penerbit UTHM
Date: 10-2018
Publisher: MDPI AG
Date: 12-04-2023
DOI: 10.3390/EN16083381
Abstract: The increased voltage loading of transformers has led to research on improving transformers’ lifespans to meet demand. Insulation oil acts as cooling medium that can significantly affect the performance of a transformer. This paper discusses an experimental study on the influences of the doping of carbon nanotube (CNT) particles and magnetic fields on the electrical properties of mineral oil (MO). An analysis of electrical properties was conducted using AC breakdown tests, Tan Delta tests, Raman measurements, and simultaneous thermal analysis. Proper preparation was considered before starting the analysis of the electrical properties. The AC breakdown voltages before and after modification were measured. The experiment results indicated that the AC breakdown of mineral oil with a suitable amount of carbon nanotube particles (0.005 g/L) and a suitable magnetic field (0.45 T) gives the highest breakdown voltage. It was found that the proper treatment of nanofluid also greatly influences breakdown voltage. Additionally, Raman measurements analyzed the physical changes in the s les. From the results obtained, the addition of carbon nanotubes and the magnetic field of mineral oil leads to an improved performance of the transformer.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 05-2019
Publisher: IOP Publishing
Date: 06-2020
DOI: 10.1088/1742-6596/1532/1/012006
Abstract: The brazing of steel and aluminium alloy using low melting point aluminium based fillers has been extensively studied and the technique has been used in many industries, especially the automotive industry. The strength and failure mode of AR500 steel and AA7075 aluminium alloy brazing joint using the Al-Si-Zn filler metal will be measured and calculated in this paper. However, the adverse effect of intermetallic phases formation on the joint strength has limited the application of this joining method.These dissimilar metals possessing a high strength joint would be of benefit to industry especially in reducing the weight of products. The torch brazing method using Al-Si-Zn base filler metal wasused to join AR500 steel and AA7075 aluminium alloy in this study. The intermetallic phase formation of the brazing on was investigated by scanning electron microscopy and the mechanical strength of the joints was evaluated by shear testing, flexural testing and low velocity impact testing. A maximum shear load of 6460 N was obtained. The presence of intermetallic phases was found to have some effect on the strength of the brazed joint. However, overall, this brazing process using Al-Si-Zn filler metal facilitates the joining of these dissimilar metals to improve the mechanical properties of the joint
Publisher: Author(s)
Date: 2018
DOI: 10.1063/1.5022932
Publisher: MDPI AG
Date: 09-07-2021
Abstract: With the development of societies, diabetic foot ulcers have become one of the most common diseases requiring lower extremity utation. The early treatment and prevention of diabetic foot ulcers can considerably reduce the possibility of utation. Using footwear to redistribute and relieve plantar pressure is one of the important measures for the treatment and prevention of diabetic foot ulcers. Thus, the evaluation and prediction of the distribution of plantar pressure play an important role in designing footwears. Herein, the finite element method was used to study plantar pressure under two kinds of foot models, namely, the skeletal structure foot model and the whole foot model, to explore the influence of human bones on the pressure of the soles of the feet and obtain accurate foot pressure. Simulation results showed that under the two models, the plantar pressure and the pressure from the footwear with ethylene vinyl acetate were all reduced. The total deformation demonstrated a slight increase. These stresses are very useful as they enable the design of suitable orthotic footwear that reduces the amount of stress in in iduals with diabetic foot ulcers.
Publisher: MDPI AG
Date: 27-08-2018
DOI: 10.3390/MET8090668
Abstract: The joining of aluminium alloys to steels has been extensively studied, especially in the automotive sector. However, aluminium alloys are known to be difficult to join with steels when methods involving fusion welding are used because of the hot cracking problem. Hence, a high-strength joint between these dissimilar metals would be of benefit especially in reducing the weight of products. In this work, the torch-brazing method was applied to join AR500 steel with AA7075 aluminium alloy using Al–Si–Zn base filler metal at various flame times. The effects of the brazing work on the intermetallic phase formation and the mechanical strength of the joints were investigated. In this work, the maximum shear load obtained was 6460 N and the presence of the intermetallic phases had reduced the shear strength of the brazed joints. However, the torch-brazing process using Al–Si–Zn filler metal had successfully facilitated the joining of these dissimilar metals.
Publisher: Informa UK Limited
Date: 20-04-2016
Publisher: Inderscience Publishers
Date: 2019
Publisher: Inderscience Publishers
Date: 2018
Publisher: MDPI AG
Date: 19-06-2020
DOI: 10.3390/EN13123181
Abstract: This paper intends to prepare a nanofluid s le by suspending Multi-walled Carbon Nanotubes (MWCNTs) at 0.005g/L concentration and analyze the behavior of electrical and dielectric properties based on the International Electrotechnical Commision test method. In order to validate the effectiveness of MWCNT nanofluid, alternating current breakdown voltage (BDV), negative polarity lightning impulse (LI), dielectric permittivity, dissipation factor (DF), DC resistivity and Raman structural measurement are executed accordingly. In the following, an analysis of the statistical distribution using the two-parameter Weibull distribution law of BDV and LI are evaluated at four experimental conditions to predict the probability of breakdown occurring at different percentages. Based on the observation, the MWCNT filler has a substantial effect in improving the BDV and LI characteristics of disposed mineral oil. The permittivity, DF and resistivity performance of MWCNT nanofluid from 25 °C to 90 °C also produces comparable and reliable performance as a fresh transformer oil. As for Raman structure, the revolution of transformer oil by doping MWCNT does not disrupt the original chemical structure of mineral oil. Hence, this study proves the improvement of the electrical and the behavior of dielectric properties and chemical structure of nanofluid, providing a huge contribution towards the development of insulating materials for transformer application.
Publisher: Penerbit UTM Press
Date: 21-06-2016
DOI: 10.11113/JT.V78.9147
Abstract: The brazing of 1080 steel to 6063 aluminium alloy was conducted under various wetting time to investigate the properties of the joint. Generally, joining of steel to aluminium using high temperature joining method can cause formations of hard and brittle intermetallic compounds that reduce the strength of joint. Brazing wetting time were varied to observe the effect of this parameter to the shear strength and microstructure at the interface of brazed joint. Shear testing showed that the strength of joint with brazing time of 5 to 15 minutes have exceeded the strength of the 6063 aluminium alloy. Microstructure analysis revealed that brazing with 15 minutes wetting time has better joining profile at interface between the steel and aluminium alloy than the other wetting durations. Optimization of the brazing wetting time improved the strength of brazed joint by minimizing the formation of brittle layer within the join interface.
Publisher: Author(s)
Date: 2018
DOI: 10.1063/1.5055489
Publisher: Blue Eyes Intelligence Engineering and Sciences Engineering and Sciences Publication - BEIESP
Date: 30-09-2019
DOI: 10.35940/IJRTE.C6208.098319
Abstract: Bearings are critical components for the transmission of motion in machines. Automotive components, especially bearings, will wear out over a certain period of time because they are constantly subjected to high levels of stress and friction. Studies have proven that coatings can extend the lifespan of bearings. Hence, it is necessary to conduct studies on coatings for bearings, particularly the mechanical and wear properties of the coating material. This detailed study focused on the mechanical properties of single-coatings of TiN and TiAIN using the finite element method (FEM). The mechanical properties that can be obtained from nano-indentation experiments are confined to just the Young’s modulus and hardness. Therefore, nanoindentation simulations were conducted together with the finite element method to obtain more comprehensive mechanical properties such as the yield strength and Poisson’s ratio. In addition, various coating materials could be examined by means of these nanoindentation simulations, as well the effects of those parameters that could not be controlled experimentally, such as the geometry of the indenter and the bonding between the coating and the substrate. The simulations were carried out using the ANSYS Mechanical APDL software. The mechanical properties such as the Young’s modulus, yield strength, Poisson’s ratio and tangent modulus were 370 GPa, 19 GPa, 0.21 and 10 GPa, respectively for the TiAlN coating and 460 GPa, 14 GPa, 0.25 and 8 GPa, respectively for the TiN coating. The difference between the mechanical properties obtained from the simulations and experiments was less than 5 %.
Publisher: Trans Tech Publications, Ltd.
Date: 09-2020
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.1010.86
Abstract: A comprehension about magnetic refrigeration which develops strong materials as the refrigerant will be explained and develop in this project. Magnetic refrigeration comes from magnetocaloric effect (MCE) which is magnetic material known as refrigerant that react with a magnetic and demagnetic field. Refrigerant plays the roll in control the performance of magnetic refrigerator. One of interesting refrigerant is MnCoGe compound which found very favourable in produce high value of MCE. From this point of view, the process of producing of MnCoGe using ball milling treatment and heat treatment had been studied. Variable of temperature in heat treatment process and following by cooling down to room temperature have been implemented in order to produce good structure of MnCoGe compound. Furthermore, from structure properties measurement found this compound produce three type of structures which are hexagonal, orthorhombic and mix structure (hexagonal and orthorhombic). Based on the different temperature of heat treatment, it indicate for 1500 o C and 1200 o C treatment are dominant to the hexagonal structure type, then for 1000 o C dominant to the orthorhombic structure and lastly for 1100 o C dominant to mix structure. Electric properties measurement found the frequency play the role in change the structure as well as in 1000 o C compound was found below 5M Hz frequency show the hexagonal structure and when increasing above 5M Hz the pattern change to orthorhombic structure respectively. Moreover, for the permittivity measurement it gives the information about conductivity and tan delta value. Systematically at 1000 o C compound found this material is more to conductor behavior compare others compound. Therefore, when the temperature is increased to 1100 o C, 1200 o C and 1500 o C then the conductivity value decreasing and its resistivity value become increasing.
Publisher: FapUNIFESP (SciELO)
Date: 09-2016
Publisher: Penerbit UTM Press
Date: 21-06-2016
DOI: 10.11113/JT.V78.9160
Abstract: This paper presents the study on interface bonding characteristic of AA7075 and AA6061 aluminum alloy with AR500 steel by torch brazing bonding process. The weight reduction in vehicles component is required for energy saving in the automobile industry. Lightweight metals such as aluminum joining with other metal especially with steel, have started replaced steel parts in automobile structures but the effect of intermetallic compound (IMC) layer formation have limited the application in this industry due to strength matter. The torch brazing method was done to join the dissimilar metal with Al-Si-Zn base filler metal for the process. The shear strength of the AA6061/AR500 joint was higher than the AA7075/AR500 joint when the joining conditions were the same. The IMC formation was observed at the joint interface, and the joints mainly fractured at this region.
Publisher: Wiley
Date: 05-07-2013
Publisher: Penerbit UTM Press
Date: 21-06-2016
DOI: 10.11113/JT.V78.9163
Abstract: This work presents a study related to the grain refinement of an aluminum A2618 alloy achieved by High-Pressure Torsion (HPT) known as a process of Severe Plastic Deformation (SPD). The HPT is conducted on disks of the alloy under an applied pressure of 6 GPa for 1 and 5 turns with a rotation speed of 1 rpm at room temperature. The HPT processing leads to microstructural refinement with an average grain size of ~250 nm at a saturation level after 5 turns. Gradual increases in hardness are observed from the beginning of straining up to a saturation level. This study thus suggests that hardening due to grain refinement is attained by the HPT processing of the A2618 alloy at room temperature.
Publisher: MDPI AG
Date: 17-09-2018
DOI: 10.3390/MET8090732
Abstract: This paper presents the effect of laminated aluminium-steel panel with different configurations in a high-speed impact test. Layering aluminium plate with high strength steel has become an interest in reducing the overall density of armour vehicle body while improving the ballistic resistance. Different layering configurations differ in laminated panel performance. Two layering configurations of double-layered panel achieving 25% of existing panel weight reduction were tested using experiment and computational method to investigate their behaviours when impacted with 7.62-mm full metal jacket at velocity range of 800–850 m/s. The ballistic performance of each configuration plate in terms of ballistic limit velocity, penetration process and permanent deformation was quantified and considered. Laminated panel with aluminium as the front layer reduced the ballistic performance of existing panel to 50% and the other panel maintained its performance. Thus, the laminated panel with aluminium as the back layer can be used in designing a protective structure for armoured vehicle while maintaining the performance of the existing vehicle in achieving weight reduction.
Publisher: MDPI AG
Date: 09-2020
DOI: 10.3390/MET10091171
Abstract: In the gas-turbine research field, superalloys are some of the most widely used materials as they offer excellent strength, particularly at extreme temperatures. Vital components such as combustion liners, transition pieces, blades, and vanes, which are often severely affected by wear, have been identified. These critical components are exposed to very high temperatures (ranging from 570 to 1300 °C) in hot-gas-path systems and are generally subjected to heavy repair processes for maintenance works. Major degradation such as abrasive wear and fretting fatigue wear are predominant mechanisms in combustion liners and transition pieces during start–stop or peaking operation, resulting in high cost if inadequately protected. Another type of wear-like erosion is also prominent in turbine blades and vanes. Nimonic 263, Hastelloy X, and GTD 111 are ex les of superalloys used in the gas-turbine industry. This review covers the development of hardface coatings used to protect the surfaces of components from wear and erosion. The application of hardface coatings helps reduce friction and wear, which can increase the lifespan of materials. Moreover, chromium carbide and Stellite 6 hardface coatings are widely used for hot-section components in gas turbines because they offer excellent resistance against wear and erosion. The effectiveness of these coatings to mitigate wear and increase the performance is further investigated. We also discuss in detail the current developments in combining these coating with other hard particles to improve wear resistance. The principles of this coating development can be extended to other high-temperature applications in the power-generation industry.
Publisher: Informa UK Limited
Date: 02-04-2016
Publisher: Author(s)
Date: 2019
DOI: 10.1063/1.5089361
Publisher: Universiti Malaysia Pahang Publishing
Date: 30-12-2016
Publisher: Universiti Malaysia Pahang Publishing
Date: 30-12-2016
No related grants have been discovered for Wan Fathul Hakim W. Zamri.