Mohd Afendi Rojan
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Preferred name
Mohd Afendi Rojan
Official Name
Mohd Afendi , Rojan
Alternative Name
Afendi, Mohd
Rojan, M. Afendi
Afendi Rojan, M.
Afendy, M.
Rojan, M. A.
Mohd Afendi, R.
Afendi, M.
Main Affiliation
Scopus Author ID
57188766103
Researcher ID
GQR-0248-2022

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  • Publication
    Finite element modelling of thin intermetallic compound layer fractures
    ( 2017)
    Ooi Eang Pang
    ;
    Ruslizam Daud
    ;
    Nasrul Amri Mohd Amin
    ;
    Mohd Afendi Rojan
    ;
    Mohd Shukry Abd Majid
    A thin intermetallic compound (IMC) of solder ball joint induces strong stress concentration between the pad and solder where a crack propagated near the IMC layer. The fracture mechanism of the IMC layer is complex due to the effect of IMC thickness, crack length, solder thickness and Young’s Modulus. At present, there is still an undefined exact geometrical model correlation for numerical simulations of IMC layer fracture. Thus, this paper aims to determine the accuracy of IMC layer models subjected to crack-to-width length ratio (a/W) in correlation with the ASTM E399-83 Srawley compact specimen model using finite element (FE) analysis. Several FE models with different geometrical configurations have been proposed under 10 MPa tensile loading. In this study, the two dimensional linear elastic displacement extrapolation method (DEM) is formulated to calculate the stress intensity factor (SIF) at the crack tip. The study showed that with an error of 0.58% to 0.59%, a width of 2.1 mm and a height of 1.47 mm can be recommended as the best geometrical model for IMC layer fracture modelling which provides a wider range for a/W from 0.45 to 0.85 instead of from 0.45 to 0.55. This result is significant as it presents a method for determining fracture parameters at thin IMC layers with a combination of singular elements with meshes at different densities which is tailored to the Srawley model.
  • Publication
    Finite element modelling of thin intermetallic compound layer fractures
    ( 2017)
    Ooi Eang Pang
    ;
    Ruslizam Daud
    ;
    Nasrul Amri Mohd Amin
    ;
    Mohd Afendi Rojan
    ;
    Mohd Shukry Abdul Majid
    A thin intermetallic compound (IMC) of solder ball joint induces strong stress concentration between the pad and solder where a crack propagated near the IMC layer. The fracture mechanism of the IMC layer is complex due to the effect of IMC thickness, crack length, solder thickness and Young’s Modulus. At present, there is still an undefined exact geometrical model correlation for numerical simulations of IMC layer fracture. Thus, this paper aims to determine the accuracy of IMC layer models subjected to crack-to-width length ratio (a/W) in correlation with the ASTM E399-83 Srawley compact specimen model using finite element (FE) analysis. Several FE models with different geometrical configurations have been proposed under 10 MPa tensile loading. In this study, the two dimensional linear elastic displacement extrapolation method (DEM) is formulated to calculate the stress intensity factor (SIF) at the crack tip. The study showed that with an error of 0.58% to 0.59%, a width of 2.1 mm and a height of 1.47 mm can be recommended as the best geometrical model for IMC layer fracture modelling which provides a wider range for a/W from 0.45 to 0.85 instead of from 0.45 to 0.55. This result is significant as it presents a method for determining fracture parameters at thin IMC layers with a combination of singular elements with meshes at different densities which is tailored to the Srawley model.
  • Publication
    Influence of friction stir welding parameters on joint defects, temperature and hardness of AA6061-T6 and S27JR mild steel FSW joint
    ( 2021-10-25)
    Wan Mohd Syafiq Wan Sulong
    ;
    Mohd Afendi Rojan
    ;
    Mazlee Mohd Noor
    The influence of welding parameters such as tool plunge depth, tool travel speed and tool tilt angle on welding temperature during friction stir welding of AA6061-T6 and S275JR mild steel was the focus of this research. Thermocouple placed in the aluminum alloy plate prior to welding was used to measure the temperature during the welding of joints under different set of parameter values. Joint appearance as well as defects occurring on the surface or within the joint was observed. Microhardness profiles were also taken by measuring microhardness values across the cross section of joints. Excessive flash, tunnel defects and insufficient welding were the type of weld defects observed on different joints with different parameters. Defects were attributed to the varied parameter values affecting the heat generation as well as the flow of the plasticized material. Highest temperature was recorded by the joint fabricated using the largest tool plunge depth, owing to the increased downwards pressure. Microhardness profiles were seen to be similar for all the welded joints. A “plateau” of low microhardness value was observed for all joints associated with the thermomechanically affected zone (TMAZ) and heat affected zone (HAZ). A wider plateau was observed for joints welded with higher tool plunge depth due to higher temperature.
  • Publication
    Effect of FSW parameters on temperature profile and grain size of AA6061-T6 and S275JR mild steel FSW joint
    ( 2021-05-03)
    Wan Mohd Syafiq Wan Sulong
    ;
    Mohd Afendi Rojan
    ;
    Mazlee Mohd Noor
    Friction stir welding (FSW) is a solid-state welding technique used to join materials such as aluminum alloy, magnesium alloy, steel and titanium. The process involves relatively low process temperatures compared to other conventional welding techniques. Welded material undergoes severe plastic deformation driven by the rotating FSW tool, which causes dynamic recrystallization of grains. In this study, the temperature during the welding of AA6061-T6 aluminum alloy and S275JR mild steel was recorded using K-type thermocouple. Grains in the stir zone (SZ) of joints were observed in order to measure the grain size. Samples were etched with Keller's reagent to reveal its microstructure. It was seen that the highest temperature was recorded when welding with a high tool plunge depth. Decreasing tool travel speed was seen to increase temperature readings. The lowest temperature was recorded when using a high tool tilt angle due to a reduced contact area between tool shoulder and weld piece. Largest observed grain size was measured in the SZ of the joint welded with a high tool plunge depth, due to the high process temperature experienced by the joint during welding.
  • Publication
    Formation of polypropylene nanocomposite joint using silicon carbide nanowhiskers as novel susceptor for microwave welding
    ( 2023-05-01)
    Foong P.Y.
    ;
    Voon Chun Hong
    ;
    Lim B.Y.
    ;
    Teh P.L.
    ;
    Mohd Afendi Rojan
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohd Khairuddin Md Arshad
    ;
    Nor Azizah Parmin
    ;
    Low F.W.
    ;
    Ruslinda A. Rahim
    ;
    Uda Hashim
    Up to present, no study has reported on the use of silicon carbide nanomaterials (SiCNMs) as susceptor for microwave welding of thermoplastics. Therefore, in this study, silicon carbide nanowhiskers (SiCNWs) was attempted as the microwave susceptor for the microwave welding of polypropylene (PP). It was observed that SiCNWs are capable of absorbing microwave and converting them into heat, leading to a sharp increase in temperature until it reaches the melting point of PP substrates. The microwave welded joint is formed after the molten PP at the interface between PP substrates is cooled under pressure. The effect of microwave heating duration and solid loading of SiCNWs suspension was studied and reported. The formation mechanism of SiCNWs reinforced PP welded joint was proposed in this study. With these remarkable advantages of microwave welding and enhanced mechanical properties of the welded joint, it is believed that this study can provide a new insight into welding of thermoplastic and material processing through short-term microwave heating.
  • Publication
    Microwave welding of thermoplastic using silicon carbide nanowhiskers as susceptor effect of heating duration
    ( 2024-06)
    Phey Yee Foong
    ;
    Voon Chun Hong
    ;
    Lim Bee Ying
    ;
    Teh Pei Leng
    ;
    Yeoh Cheow Keat
    ;
    Mohd Afendi Rojan
    ;
    Nor Azizah Parmin
    ;
    Subash Chandra Bose Gopinath
    ;
    Foo Wah Low
    ;
    Muhammad Kashif
    ;
    Nor Azura Abdul Rahman
    ;
    Sam Sung Ting
    ;
    Veeradasan Perumal
    Microwave welding is becoming more popular than conventional joining methods due to its advantages such as rapid and localised heating as well as applicable to components with complicated geometry. Previously reported susceptor, such as carbonaceous materials and conductive polymers, are toxic and the welding process involving these susceptors is time-consuming. Because of its exceptional microwave absorption and biocompatibility, silicon carbide nanowhiskers (SiCNWs) was employed as the microwave susceptor for microwave welding. Microwave welding in this study comprises of only three simple steps: SiCNWs suspension preparation, SiCNWs application and microwave heating. The weld strength of welded joint was then characterised using tensile test and energy dispersive x-ray spectroscopy equipped scanning electron microscopy (EDS-SEM) to study its mechanical properties and cross-section microstructure. The influence of microwave irradiation time was studied in this study, and it is found that the weld strength rose with the extension of microwave irradiation time, until a maximum weld strength of 1.61 MPa was achieved by 17 s welded joint. The development of SiCNWs reinforced PP nanocomposite welded joint layer is responsible for the enhanced weld strength. Prolonged heating duration may also result in flaws such as void formation at the welded joint, which subsequently lowered the weld strength to 0.60 MPa when the heating duration was extended to 20 s. In sum, a strengthen welded joint can be formed with rapid microwave heating under the proper control of heating duration.
  • Publication
    Investigation of vortex-induced vibration with different width of two bluff bodies in tandem arrangement for energy harvesting system
    ( 2021-05-24)
    Aziz N.A.
    ;
    Mohd Nor Fakhzan Mohd Kazim
    ;
    Nasrul Amri Mohd Amin
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Afendi Rojan
    ;
    Nasir N.F.M.
    Due to imperative of enhancement on Vortex-induced vibration (VIV) energy harvesting as renewable energy sources, dual bluff bodies which are triangle and cylinder in tandem arrangement with different width from each other are studied in terms of total deformation, directional deformation and voltage generated in order to determine the better bluff bodies for the piezoelectric film. This is due to the unsymmetrical wakes pattern, low frequency vortices, and low energy output produced by the system. The length and height of the bluff bodies were fixed to 0.1m and airflow used for simulations was 1.46m/s. The spacing ratio was calculated from 1 to 6 to examine various width between two bluff bodies that will affect the formation of the vortex at the downstream area. From the results, it can be concluded that triangle bluff bodies in tandem arrangement 0.6m from each other have resulted in the highest total deformation and effective voltage generated of 0.47mm, and 3.05mV, respectively. These data indicated the highest ability of energy harnessing. Furthermore, this model results in a consistent flagging direction of the piezoelectric that implying a good energy harvesting system.
  • Publication
    Design and analysis of exhaust manifold for a single-cylinder internal combustion engine (ICE)
    ( 2021-05-24)
    Aziz N.A.
    ;
    Rahman M.T.A.
    ;
    Amin N.A.M.
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Afendi Rojan
    ;
    Nasir N.F.M.
    ;
    Rahman Y.M.N.
    An efficient exhaust system is vital to maximising the performance of an internal combustion engine (ICE), hence improving overall vehicle performance. To have an efficient exhaust system, the amount of exhaust backpressure is to be minimised. To decrease the backpressure effects in the exhaust system, the exhaust has to be redesigned according to the certain bending radius, length of straight pipe and bending angle and pipe diameter. This paper presents design and analysis of the exhaust system used in Shell Eco-Marathon 2019 competition. In this project, the exhaust manifold was redesigned according to the specification of the chassis, the exhaust outlet in the engine and the rules and regulations of the competition. Computational Fluid Dynamic (CFD) analysis was employed to identify the optimum exhaust system design with minimum pressure loss. Among the tested models, the exhaust manifold with 100 mm length, 30° bending angle, 34 mm diameter, and 40 mm bending radius was the optimised design that resulted in the lowest pressure loss of 12.24 kPa. This study shows that a small bending angle with a short straight pipe has led to a smoother exhaust flow and even exhaust velocity across the model.
  • Publication
    Tensile Properties of Diffusion Bonded Duplex Stainless Steel to Low Carbon Steel
    ( 2020-01-01)
    Baharudin B.A.
    ;
    Hussain P.
    ;
    Mustapha M.
    ;
    Ayob F.
    ;
    Ismail A.
    ;
    Ab Rahman F.
    ;
    Khalid P.Z.M.
    ;
    Hamid D.A.
    ;
    Mohd Afendi Rojan
    The diffusion bonding is one of the methods used to join dissimilar metals. Specimens of duplex stainless steel and low carbon steel were joined by diffusion bonding under varied temperature and holding time. The specimens were clamped using jigs and heated in a furnace. Tensile test was performed on the joined samples. The effect of bonding time and holding temperature on tensile strength and quality of the diffusion bonds were observed. Tensile strength of the joints was examined and the highest tensile strength of 116.12 MPa are obtained at temperatures of 900 °C and holding time of 180 min.
  • Publication
    Effect of Microwave Power and Clamping Pressure on the Microwave Welding of Polypropylene Using Silicon Carbide Nanowhiskers as Microwave Susceptor
    ( 2022-01-01)
    Foong P.Y.
    ;
    Voon Chun Hong
    ;
    Lim B.Y.
    ;
    Teh P.L.
    ;
    Mohd Afendi Rojan
    ;
    Nor Azizah Parmin
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohd Khairuddin Md Arshad
    ;
    Low F.W.
    ;
    Mahalingam S.
    ;
    Manap A.
    ;
    Ruslinda A. Rahim
    ;
    Uda Hashim
    Due to their excellent dielectric properties and the rapid response to microwave irradiation, silicon carbide nanowhiskers (SiCNWs) were employed as microwave susceptor in this study to absorb microwave and locally melt the surrounding polypropylene (PP) substrates for the joining of PP substrates. Complete welded joint is formed after the melted PP was cooled and resolidified. Other than microwave susceptor, SiCNWs also acted as the nanofillers in strengthening the welded joint through the formation of SiCNWs reinforced PP nanocomposite at the interface of PP substrates. Besides, the effect of microwave power on the microwave welding of PP substrates using SiCNWs as susceptor was studied and reported. It was found that the tensile strength and modulus of elasticity of the welded joint improved as microwave power increased. However, it deteriorates the flexibility of the welded joint as high stiffness SiCNWs were incorporated deeper into the PP matrix which restricted the PP chain mobility. Aside from microwave power, clamping pressure is also critical in determining the mechanical properties of a welded joint. When compared to unclamped welded joint, the tensile strength, modulus of elasticity and flexibility of welded joint subjected to clamping pressure improved drastically. Moreover, the tensile strength of welded joint increased when the clamping pressure was increased from P1 to P3, but decreased when the clamping pressure was further increased to P4 due to the occurrence of flashing at welded joint. The formation mechanism of SiCNWs reinforced PP welded joint was also proposed in this study. Compared to conventional welding, this welding process is easy, straightforward and is able to produce welded joint with outstanding mechanical properties via precise controlling of the processing parameters. Thus, microwave welding is thought to offer an option for the joining of thermoplastics and other applications.