Nurul Razliana Abdul Razak
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Preferred name
Nurul Razliana Abdul Razak
Official Name
Nurul Razliana, Abdul Razak
Alternative Name
Razak, N. R.Abdul
Razak, N. R.A.
Abdul Razak, N. R
Razak, Nurul Razliana Abdul
Main Affiliation
Scopus Author ID
56353055800

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Characterisation and properties of aluminium/zinc oxide composites as catalytic gases from depolymerisation of low density polyethylene to liquid oil

2012 , Nurul Razliana Abdul Razak

The effects of addition zinc oxide (ZnO) or magnesium trisilicate (MTS) in aluminum (Al) matrix composites on physical and mechanical properties at different sintering temperature were studied. The Al/ZnO and Al/MTS composites prepared by powder metallurgy (PM) method. The composites were mixed using a milling machine at a speed of 131 rpm with ball to powder weight ratio is 10:1, then compressed at 200 MPa for 2 minutes. The results show that the additions of ZnO or MTS in Al composites have increased the density and hardness but decrease the compressive strength of the composites. The Al/ZnO or Al/MTS composites sintered at 750 °C have higher density, hardness and compressive strength than composites sintered at 650 °C. The effect of different sintering temperature gives effect to intensity of the composites. The microstructure of Al/ZnO or Al/MTS sintered at 750 °C show better interaction between filler and Al matrix. The effect of stearic acid or zinc stearate in Al/ZnO composites has increased the hardness and compressive strength of composites but density reduced at sintered 750 °C. The XRD patterns of Al/ZnO composites with stearic acid or zinc stearate show the changed in intensity peak of composites. The presence of stearic acid and zinc stearate as binder improved the adhesion and interaction between ZnO and Al matrix composites. The Al/ZnO composites with zinc stearate have higher physical and mechanical properties compared to other composites. The applied of Al/ZnO composites with zinc stearate as catalyst in the depolymerisation of low density polyethylene (LDPE) has produced yield 76.22 % of liquid oil. The liquid oil product consists of light hydrocarbons such as gasoline was proven by using gas chromatography - mass spectrometer (GC-MS).

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Effects of Surface Finish on Sn-3.0Ag-0.5Cu Solder Joint Microstructure and Strength

2021-03-01 , Siti Farahnabilah Muhd Amli , Mohd Arif Anuar Mohd Salleh , Mohd Izrul Izwan Ramli , Nurul Razliana Abdul Razak , Yasuda H. , Chaiprapa J. , Nogita K.

The effects of copper organic solderability preservative (Cu-OSP) and electroless nickel immersion gold (ENIG) surface finish reflowed on Sn-3.0Ag-0.5Cu (SAC305) solder have been investigated in detail. Besides conventional cross-sectional microstructure observation, advanced characterization techniques such as synchrotron radiography imaging and synchrotron micro-x-ray fluorescence (µ-XRF) were utilized to elucidate the microstructural evolution in the solder joints during soldering. Additionally, high-speed shear testing was performed to understand the influence of the surface finish on the solder joint strength. The results indicated that the presence of nickel (Ni) from the ENIG surface finish decreased the growth rate but increased the amount of small Cu6Sn5 primary intermetallics, resulting in a slight reduction of the average interfacial intermetallic compound (IMC) thickness in the SAC305/ENIG solder joints. Due to the refined control of the solder joint microstructure, the average high-speed shear strength was higher for as-reflowed SAC305/ENIG versus SAC305/Cu-OSP solder joints. These results indicate a significant influence of the surface finish on SAC305 solder joint microstructure and strength and could provide a basis to improve solder joint strength.

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Development of savonius and darrieus vertical axis hybrid wind turbine to increase effectiveness in wind energy conversion system

2013 , Nurul Razliana Abdul Razak

This thesis presents the investigation of the potential of wind energy in Perlis and the development of Savonius and Darreius Vertical Axis Hybrid Wind Turbine for the low wind speed application (below 2 m/s). The objectives of this research are to investigate the potential of wind energy based on the weather data in Kangar, Perlis. Next, to study the characteristic of Horizontal Axis Wind Turbine (HAWT) and Vertical Axis Wind Turbine (VAWT) suitable for low wind speed condition. Lastly, to develop Savonius and Darrieus Vertical Axis hybrid Wind Turbine and analyze the performance of Hybrid turbine towards the efficiency wind energy conversion. Wind speed data were measured at Centre of Excellence for Renewable Energy (CERE) station, University Malaysia Perlis located in Kangar, Perlis. The for wind speed and wind power density data was analyzed on a daily for 1 and half year, monthly and yearly basis. Wind speed in Malaysia is governed by the two monsoons that are north-east monsoon and south-east monsoon. During the south-east monsoon the average wind speed is less than 2 m/s while in north-east monsoon the average speed of the wind is around 2-5 m/s. In order to overcome these challenges, an appropriate wind turbine model is designed with specific attention given to its sensitivity to low wind speed application. As such as the matter, the Vertical Axis Hybrid Wind Turbine designed is opted to combine that of Savonius and Darrieus turbines. The test had been done by using a blower as the source of the wind for three designs of the turbine that are Savonius turbine, Darrieus turbine and Hybrid (Savonius and Darrieus) Turbine. The end results are encouraging as the Hybrid turbine shows to posses a good starting characteristic and its increase efficiency to 0.44% compared with a single design of VAWT. From the result of wind energy data in kangar Perlis and performance of the Hybrid turbine, it is believed that Kangar is not suitable for installation of wind turbine since it is located in a hilly area (wind obstruction). Installation in the coastal area or an open area may increase effectiveness of the Hybrid turbine for wind energy conversion.

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Microstructure, thermal behavior and joint strength of Sn-0.7Cu-1.5Bi/electroless nickel immersion gold (ENIG)

2021-01-01 , Teoh Ai Ling , Mohd Arif Anuar Mohd Salleh , Dewi Suriyani Che Halin , Foo Kai Loong , Nurul Razliana Abdul Razak , Yasuda H. , Nogita K.

This paper details an investigation into the microstructure, thermal behaviors and joint strength of Sn-0.7Cu-1.5Bi solder alloy on electroless nickel immersion gold (ENIG) surface finish. Besides conventional techniques, the real-time synchrotron imaging was used to analyze the microstructure evolution in Sn-0.7Cu-1.5Bi/ENIG. This research investigated the growth behavior of the primary (Cu,Ni)6Sn5intermetallic compounds (IMCs) in the solder joint with the Bi alloying. The elemental distribution analysis showed the Ni diffused from the ENIG surface finish and dissolved into the bulk solder during solidification and that the size of the primary (Cu,Ni)6Sn5IMCs decreased due to the addition of 1.5 wt% Bi. The average kinetic growth rate of the primary (Cu,Ni)6Sn5IMCs in Sn-0.7Cu-1.5Bi/ENIG was lower than that of the Sn-0.7Cu/ENIG. The thermal analysis revealed that the pasty range slightly increased and the undercooling degree decreased due to the addition of 1.5 wt% Bi for free-standing solder and soldering on ENIG surface finish. The shear strength of the Sn-0.7Cu-1.5Bi/ENIG was determined using a high-speed bond tester, and it increased by ~12% at bulk solder fracture of ~15% within the solder joint interfacial fracture due to the addition of 1.5 wt% Bi into the Sn-0.7Cu. These occurrences can be attributed to the solid solution strengthening effect at the bulk solder and the formation of finer interfacial (Cu,Ni)6Sn5IMCs within the solder joints. The results indicated that the microstructural changes, especially the size reduction of IMCs, in Sn-0.7Cu-1.5Bi/ENIG impacted the joint strength.

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Controlling porosity during transient liquid phase bonding for high-temperature soldering processes

2023-01-01 , Nurul Razliana Abdul Razak , Tan X.F. , McDonald S.D. , Bermingham M.J. , Venezuela J. , Nishimura T. , Nogita K.

Exploiting the growth rate dependency of intermetallic compounds (IMCs) on the substrate composition, the possibility of controlling porosity during transient liquid phase (TLP) bonding via a composition gradient is investigated. A Cu substrate with a variable Ni concentration was prepared through selective electroplating and subsequent heat treatment. When this substrate reacted with a molten Sn-rich alloy, there was a non-uniform growth of the Cu6Sn5 IMC. It is proposed that by tailoring the direction of the composition gradient in the substrate, the IMC growth rate can be controlled in such a way as to progressively move the solid-liquid front to redistribute any porosity away from the central region of the joint and thereby improve reliability.

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