Mas Hassan | Universiti Malaysia Pahang (UMP) (original) (raw)

Papers by Mas Hassan

IOP conference series, Jan 16, 2019

In this study, the effect of die angle on the microstructure and mechanical properties of industr... more In this study, the effect of die angle on the microstructure and mechanical properties of industrial aluminium alloy AA6061 produced by severe plastic deformation (SPD) through equal channel angular pressing (ECAP) is examined. The objectives of the present investigation are to evaluate the effect of ECAP die angle on the microstructure and mechanical properties of ECAP-ed AA6061. Heat treated AA6061 were divided to three conditions which is non-ECAP, ECAP-ed by 126º channel angle and ECAP-ed by 120º channel angle. The hardness evaluation and microstructural analysis were done on the samples after ECAP. The grain size of all materials was compared by applying the technique of grain size analysis while the hardness of the materials was compared by performing Vickers hardness calculation. From the hardness test, it found that 120º channel angle gives out an increment of hardness by 43.64% while for 126º channel angle the increment hardness is 40.14% compared to non-ECAP AA6061. Microstructural analysis reveals both ECAP-ed samples have elongated and refined grain size with smaller precipitate particulate compared to non-ECAP sample however no significant difference between the angles were observed. High strain induced during ECAP process increase dislocation in AA6061 and breaking the precipitate thus causing high hardness due to grain refinement. Varying the ECAP die angle may lower the pressure used during pressing without compromising the benefit of ECAP process in producing materials with improved mechanical properties.

Journal of the mechanical behavior of biomedical materials, 2016

New promising techniques for depositing biocompatible hydroxyapatite-based coatings on biocompati... more New promising techniques for depositing biocompatible hydroxyapatite-based coatings on biocompatible metal substrates for biomedical applications have continuously been exploited for more than two decades. Currently, various experimental deposition processes have been employed. In this review, the two most frequently used deposition processes will be discussed: a sol-gel dip coating and an electrochemical deposition. This study deliberates the surface morphologies and chemical composition, mechanical performance and biological responses of sol-gel dip coating as well as the electrochemical deposition for two different sample conditions, with and without coating. The review shows that sol-gel dip coatings and electrochemical deposition were able to obtain the uniform and homogeneous coating thickness and high adherent biocompatible coatings even in complex shapes. It has been accepted that both coating techniques improve bone strength and initial osseointegration rate. The main advan...

Jurnal Teknologi

The effects of oxide interlayer on cobalt-chromium-molybdenum substrate were investigated in orde... more The effects of oxide interlayer on cobalt-chromium-molybdenum substrate were investigated in order to improve the quality of hydroxyapatite (HA) coating as well as enhance the cell responses. Substrates were oxidized at temperature of 850 °C and 1050 °C for 3 hours. Oxidized substrates were then coated with HA slurry using dip coating technique. Analysis of surface morphology, thickness and chemical composition of oxide interlayer prior to HA coating were performed using field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy and grazing X-ray diffraction respectively. It seems that rough surface of oxide interlayer provides better mechanical interlocking of HA particles to the substrate surface with no visible micro-cracks. In addition, the HA coated substrates with oxide interlayer also demonstrate strong attachment and better proliferation of cells compared to HA coated substrates without oxide interlayer. The results also demonstrates that cells were sp...

Advanced Structured Materials, 2022

Journal of Physics: Conference Series, 2021

This work aims to study the effect of mechanical treatment technique on titanium coated with PVD ... more This work aims to study the effect of mechanical treatment technique on titanium coated with PVD for the enhancement of corrosion resistance for the biomedical implant. First, substrates were coated with TiN via PVD then applied the mechanical treatment through ultrasonic vibration. Results show that all coated samples treated with ultrasonic vibration improve the surface of the coated sample and produce a compact coating as compared with a substrate coated without mechanical treatment. The corrosion test evaluated by Potentiodynamic polarization and Electrochemical Impedance Spectroscopy indicated that all coated samples treated with mechanical treatment showed high corrosion resistance as compared with the untreated sample. It can be concluded that mechanical treatment which is a simple technic can be used as an alternative to improve the corrosion resistance thus reduce the implant and manufacturing cost for biomedical applications.

1 Faculty of Technical and Vocasional, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, P... more 1 Faculty of Technical and Vocasional, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia 2 Faculty of Mechanical Engineering, Universiti Malaysia Pahang, 26600 Pekan, Pahang, Malaysia 3 Faculty of Engineering, Universitas Negeri Padang, Air Tawar Padang 25131 Sumatera Barat, Indonesia 4 Faculty of Technology Management, Universiti Tun Hussein Onn Malaysia (UTHM), Parit Raja, Batu Pahat, Johor, Malaysia

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2020

Magnesium alloys have been widely used in biodegradable applications due to it tends to corrode i... more Magnesium alloys have been widely used in biodegradable applications due to it tends to corrode inside the human body and combined with its initial mechanical property. Current research revealed that the structural stability of the implant is disturbed and lost rapidly due to the increased rate of degradation of magnesium inside the human body. Because of that, non-traditional machining method such as electrical discharge machining (EDM) die sinking process is implemented to create an intricate form with a high tolerance of magnesium alloy. The advantages of EDM are that it allows a versatile adaption of implant behaviour in machining complex 3D structures along with high corrosion resistant properties of electrochemical surface treatment. Various material types with different parameters are investigated to determine the influence of input process parameters on the energy saving, and machining characteristics included surface roughness, material removal rate, and tool wear rate. In addition to improving the machining performance especially in energy-saving, input on the machining parameter needs to be considered due to interaction with added conductive particles which would affect the size of discharge energy. The objective of this paper is to summarize the findings in research of EDM's energy-saving and machining characteristics on magnesium alloy and to explore challenging issues that need to be resolved for future references and recommendations.

MATEC Web of Conferences, 2017

In an impact, a structure is rarely subjected to pure axially loading. Load endured by an axially... more In an impact, a structure is rarely subjected to pure axially loading. Load endured by an axially loaded column has been analytically derived by previous researchers, whereas it is very limited works on predicting the obliquely loaded column performance. In this study, the force response curve of the obliquely loaded empty aluminum column is analyzed and compared to its axially loaded column. Theoretical formula to calculate the axial mean force has been applied to obliquely loaded column, and it has yields a largely deviated value. Thus, a modified equation to cater for obliquely loaded column has been proposed.

Jurnal Teknologi, 2016

Cathodic arc physical vapor deposition (CAPVD) is one of the promising techniques that have a pot... more Cathodic arc physical vapor deposition (CAPVD) is one of the promising techniques that have a potential to coat titanium nitride (TiN) on biomedical implants due to its good adhesion and high evaporation rate. However, this method emits microdroplets which have the possible detrimental effect on the coating performance. Past studies indicated that micro droplets can be controlled through proper deposition parameters. In the present work, an attempt was made to study the effect of nitrogen gas flow rates (100 to 300 sccm) on TiN coating of the Ti-13Zr-13Nb biomedical alloy. Scanning electron microscopy (SEM) was used to evaluate surface morphology and coating thickness while crystal phase of the coated substrates was determined using X-Ray Diffraction (XRD). Image analysis software was employed to quantify microdroplets counts. Results show that higher nitrogen gas flow rate able to decrease a significant amount of microdroplets and concurrently increase the thickness of TiN coating....

Titanium Alloys - Towards Achieving Enhanced Properties for Diversified Applications, 2012

Advanced Materials Research, 2011

... 707 Page 5. References [1] S. Sathish, M. Geetha, ST Aruna, N. Balaji, KS Rajam and R. Asokam... more ... 707 Page 5. References [1] S. Sathish, M. Geetha, ST Aruna, N. Balaji, KS Rajam and R. Asokamani:Wear. (2011).In Press. ... DOI References [1] S. Sathish, M. Geetha, ST Aruna, N. Balaji, KS Rajam and R. Asokamani:Wear. (2011).In Press. doi:10.1007/s10800-011-0256-5 ...

Surface and Coatings Technology, 2014

Surface modification of metallic implants is often required to facilitate positive interaction be... more Surface modification of metallic implants is often required to facilitate positive interaction between the implant and the surrounding hard tissue. In the present study, a polymer-ceramic composite coating of poly (ε-caprolactone)/hydroxyapatite (PCL/HA) was successfully deposited on a Ti6Al4V substrate by dip coating technique in chloroform suspension at room temperature. The influence of PCL concentration and dip coating parameters was studied and the process parameters were optimized to obtain a homogeneous, crack free, densely packed and adhesive coating. The surface of coating was rough and contained surface level pores, which are necessary for ingrowth of osseous tissue. The corrosion behaviour of the coated substrates was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), the results of which showed that the composite coating of PCL/HA substantially enhanced the corrosion resistance of Ti6Al4V alloy.

International Journal of ADVANCED AND APPLIED SCIENCES, 2017

The corrosion phenomena are always give bad impact to any metal products including human implants... more The corrosion phenomena are always give bad impact to any metal products including human implants. This is due to the corrosion impacts are harmful for hard tissues and soft tissues. There are many methods to prevent the process of corrosion on implant materials such as coating with bioceramic materials and modify the implant surface with surface modification techniques. However, until now there is still no gold standard to overcome this problem and it is remain in researching process. Thus, the aim of this research is to investigate the potential and economical surface modification method to reduce the corrosion effects on Cobalt-Chromium-Molybdenum (Co-Cr-Mo) based alloy when insert in human body. The thermal oxidation process was selected to treat Co-Cr-Mo surface substrate. Firstly, Co-Cr-Mo alloy was heated in muffle furnace at constant temperature of 850°C with different duration of heating such as 3 hours and 6 hours in order to analyze the formation of oxide layer. The corrosion behaviours of untreated sample and oxidized sample were investigated utilizing potentiodynamic polarization tests in simulated body fluids (SBF). The Vickers hardness after corrosion testing was measured in order to evaluate the effect of thermal oxidation in reducing corrosion rate. Based on the results obtained it is clearly showed that substrates undergone thermal oxidation with 6 hours duration time performed better than 3 hours duration, with the hardness value 832.2HV vs. 588HV respectively. Dense oxide layer and uniform thickness formed on the oxidized substrates able to help in reducing the corrosion effects on Co-Cr-Mo alloy without degraded its excellent mechanical properties. The microstructures of oxidized substrates before and after corrosion test were also analyzed using FESEM images for better observations. It was determined that corrosion resistance of Co-Cr-Mo substrate can be increased with oxide layer formed on the alloys using thermal oxidation process.

Applied Mechanics and Materials, 2016

... Omar My wonderful brothers and sisters Asmalinda Binti Hj. Hassan Mohd Khamsyari Bin Hj. Hass... more ... Omar My wonderful brothers and sisters Asmalinda Binti Hj. Hassan Mohd Khamsyari Bin Hj. Hassan Irwan Bin Hj. Hassan Syed Syafiq Bin Hj. Hassan Muhammad Hafiz Bin Hj. Hassan Nurul Hafizah Binti Hj. Hassan And last but not least to all my relatives and my close friends ...

Electrical discharge machining (EDM) is a process for shaping hard metals and forming deep comple... more Electrical discharge machining (EDM) is a process for shaping hard metals and forming deep complex shaped holes by arc erosion in all kinds of electro-conductive materials. The objective of this paper is to study the influence of operating parameters of tungsten carbide on the machining characteristics such as surface quality, material removal rate and electrode wear. It is followed by optimizing the machining condition for confirmation test purposes. Then, the conformation test needed to evaluate the error margin between predicted result by software and confirmation result by experiment in terms of the machining characteristics. The effectiveness of EDM process with tungsten carbide, WC-Co is evaluated in terms of the material removal rate, the relative wear ratio and the surface finish quality of the workpiece produced. It is observed that copper tungsten is most suitable for use as the tool electrode in EDM of WC-Co. Better machining performance is obtained generally with the electrode as the cathode and the workpiece as an anode. In this paper, a study was carried out on the influence of the parameters such peak currrent, power supply voltage, pulse on time and pulse off time. The surface quality that was investigated in this experiment was surface roughness using perthometer machine. Material removal rate (MRR) and electrode wear (EW) in this experiment was calculated by using mathematical method. The result of the experiment then was collected and analyzed using STATISTICA software. This was done by using the design of experiments (DOE) technique and ANOVA analysis.

The Wire Electro Discharge Machining (WEDM) process is a violent thermal process where literally ... more The Wire Electro Discharge Machining (WEDM) process is a violent thermal process where literally thousands of electrical discharges are produced in a fraction of a second in order to erode a certain volume of metal. The process is most used in situations where intricate complex shapes need to be machined in very hard materials (such as hardened tool steel). However, the process generates surface that have poor properties such as high tensile residual stresses, high surface roughness, presence of micro-cracks and micro-voids. These properties vary with different levels of the main machining parameters. The aim of this paper is to present experimental work that has been done in order to quantify the effect of some of the main WEDM parameters on the surface texture of AISI 4140 steel. 2D surface measurements were taken on all WEDM samples and 2D surface characterization has been carried out in order to calculate the different surface texture parameters. In this work, the surface characteristics caused by WEDM were analyzed by Scanning Electron Microscopy (SEM).

Advanced Materials Research, 2013