Browsing School of Materials Engineering (Articles) by Author "Khairel Rafezi, Ahmad, Dr."
Now showing items 1-20 of 21
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Development of dense hydroxyapatite-ni by modified electroless deposition technique.
Sri Asliza, Md Amin; Mohd Zaheruddin, Kasmuin; Azmi, Rahmat, Dr.; Shamsul Baharin, Jamaludin, Prof. Dr.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2014)Ni deposited on HA powder was prepared by electroless plating process without sensitization and activation treatment. The deposited powder obtained was characterized by energy dispersive spectroscopy (EDX) and x-ray ... -
Effect of different nickel content on the mechanical properties of hydroxyapatite-ni composites from coated powders
Sri Asliza, Md Amin; Mohd Zaheruddin, Kasmuin; Azmi, Rahmat, Dr.; Shamsul Baharin, Jamaludin, Prof. Dr.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2014)HA-Ni composites were fabricated by uniaxial pressing from coated powders, in which HA particles were successfully coated with nickel precursor by the electroless deposition method. The compacted powders sintered at ... -
Effect of roughness of hypo-and hyper-eutectic Al-Si piston alloy on wear characteristics under lubrication
Riyadh A., Al-Samarai; Haftirman, Dr.; Khairel Rafezi, Ahmad, Dr.; Yarub, Al-Douri, Assoc. Prof. Dr. (Elsevier B.V., 2013)The tribological behavior of tow Al-Si alloys under the influence of surface roughness average was investigated for the present study. The silicon content of these alloys ranged 10 and 16-wt% Si, and includes hypoeutectic ... -
Effect of spot welding current and cycles on the mechanical properties of welded galvanized steel sheets
Shamsul Baharin, Jamaludin, Prof. Dr.; Mazlee, Mohd Noor, Dr.; Muhammad Rifki, Ismail; Khairel Rafezi, Ahmad, Dr.; Kamarudin, Hussin, Brig. Jen. Dato' Prof. Dr. (Trans Tech Publications, 2013)Studies on the effects of welding current and cycles were carried on the galvanized steel sheets using spot welding. The welding currents used were 3 kA, 5 kA 6 kA and the welding cycles were 4, 6 and 8. Tensile shear and ... -
Electrochemical measurement of PBS using cyclic voltammetry and AAO fabricated at ambient temperature and low potential
Alaba Oladeji, Araoyinbo; Mohd Nazree, Derman, Dr.; Azmi, Rahmat, Prof.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)Anodic aluminium oxide fabricated at ambient temperature and low potential in phosphoric acid electrolyte was used as the working electrode for the electrochemical measurement of phosphate buffer saline under different pH ... -
Evaluate the effects of various surface roughness on the tribological characteristics under dry and lubricated conditions for Al-Si alloy
Riyadh A., Al-Samarai; Haftirman, Dr.; Khairel Rafezi, Ahmad, Dr.; Yarub, Al-Douri, Assoc. Prof. Dr. (Scientific Research Publishing Inc. All rights reserved., 2012-07)The effect of surface roughness average of hypereutectic aluminum silicon alloys (with 16 wt% Si) on the friction and wear was investigated. Various surface roughness average (Ra) of different degrees was verified as well ... -
Evolution of the retrogression and reaging treatment on microstructure and properties of Aluminum Alloy (Al-Zn-Mg-Cu)
Naeem, Haider T.; Khairel Rafezi, Ahmad, Dr.; Kahtan Sadiq, Muhammed, Dr; Azmi, Rahmat, Prof. (Trans Tech Publications Inc., 2014-04)In this study the evolution of the retrogression and reaging (RRA) heat treatment process on microstructure and mechanical properties of AA 7075 Al-alloys which produced by semi-direct chill (DC) casting process were ... -
Fire resistance of biomass ash panels used for internal partitions in buildings
Roshazita, Che Amat; Norlia, Mohamad Ibrahim; Nur Liza, Rahim; Nur Saidatul Balqish, Ahmad Tajudin; Khairel Rafezi, Ahmad, Dr. (Elsevier B.V., 2013)This study was to develop fire-resistant panels with a high biomass ash ratio from the combustion of EFB at an industrial scale to be used in different fire-resistant internal partitions in buildings and industrial ... -
Intermetallic compound formation on solder alloy/cu-substrate interface using lead-free sn-0.7cu/recycled-aluminum composite solder
Flora Somidin; Mohd Arif Anuar, Mohd Salleh; Khairel Rafezi, Ahmad, Dr. (Scientific.Net, 2012-12)Feasibility of using recycled-Aluminum (re-Al) as reinforcement particulates in Sn-0.7Cu is assessed by powder technology method, whereby re-Al particulates are produced from discarded aluminum beverage cans. This paper ... -
Kinetic and thermodynamic studies on adsorption of copper ions onto pomelo peel (citrus grandis)
Mst. Noorzahan, Begum, Dr.; Aimi Noorliyana, Hashim; Md Fazlul, Bari, Dr.; Norzilah, Abdul Halif, Dr.; Nur Hidayah, Ahmad Zaidi; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)The ability of pomelo peel (PP) as natural adsorbent to remove Cu (II) ions from aqueous solution was investigated. The influence of solution pH, contact time and temperature were evaluated. Cu (II) removal increased as ... -
Mechanical properties of dissimilar welds between stainless steel and mild steel
Shamsul Baharin, Jamaludin, Prof. Dr.; Mazlee, Mohd Noor, Dr.; Shahzan Kamarul, A. Kadir; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)Joining of stainless steel type 304 to mild steel was carried out using a gas tungsten arc welding (GTAW). Samples were welded using stainless steel welding electrode: (AWS: E308l-16) and mild steel welding electrode: (AWS: ... -
Organic dye degradation with TiO2 catalyst/AAO template in the presence of H2O2
Alaba Oladeji, Araoyinbo; Mohd Nazree, Derman, Dr.; Azmi, Rahmat, Prof.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2013)In this study, anodic aluminum oxide (AAO) fabricated from phosphoric acid electrolyte at ambient temperature was used as the porous template, while a sol gel procedure was used for the preparation of the TiO2 sol with the ... -
Preparation and characterization of Co-HA powder using modified electroless method
Mohd Zaheruddin, Kasmuin; Sri Asliza, Md Amin; Azmi, Rahmat, Prof. Madya Dr.; Shamsul Baharin, Jamaludin, Prof. Dr.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2014)C0-HA composite produced by simple electroless deposition method was studied. From the particle size analysis by Malvern particles analyzer its shows that 19% increment in average of the particle size powder increase after ... -
Preparation and characterization of silica aerogel immobilized with cyanex 301 for extraction of Zn(II)
Mst. Noorzahan, Begum, Dr.; Md Fazlul, Bari, Dr.; Salmie Suhana, Che Abdullah; Khairel Rafezi, Ahmad, Dr.; Nasim, Ahmed, Dr. (Trans Tech Publications, 2013)A new solid phase extractant silica aerogel immobilized with Cyanex 301 {bis(2,4,4- trimethylpentyl) dithiophosphinic acid} (SAWC) was prepared via a sol- gel method and investigated for the extraction of Zn(II) from aqueous ... -
The sensing mechanism and detection of low concentration acetone using chitosan-based sensors
Tulus Ikhsan, Nasution; Irwana, Nainggolan, Dr.; Sabar Derita, Hutagalung, Dr.; Khairel Rafezi, Ahmad, Dr.; Zainal Arifin, Ahmad (Elsevier B. V., 2013)This paper aims to discuss the usage of chitosan film sensors to detect acetone concentrations in human breath, in order to precisely diagnose diabetes mellitus in patients. Acetone concentration in the breath varies from ... -
Sintering behavior and microstructure evolution of mechanically alloyed W–bronze composite powders by two-step ball milling process
Kahtan S., Muhammed, Dr.; Azmi, Rahmat, Prof.; Khairel Rafezi, Ahmad, Dr. (Elsevier, 2013-01)The miscibility of W in Sn and Cu is extremely poor. Sintering of W–bronze composites to their full density is proved to be difficult. To tackle this problem, the ball milling process of the W–bronze powder mixture proposed ... -
Sintering effects on mechanical properties of Co-HA composite prepared by modified electroless deposition.
Mohd Zaheruddin, Kasmuin; Sri Asliza, Md Amin; Azmi, Rahmat, Dr.; Shamsul Baharin, Jamaludin, Prof. Dr.; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2014)Co-HA composite produced using electroless deposition without conventional sensitization and activation treatment was studied with varying sintering temperature (1100°C, 1200°C and 1250°C). The particles size, bulk density, ... -
Synthesis and characterization of iron produced from iron mill scale
Ruhiyuddin, Mohd Zaki; Murizam, Darus; Khairel Rafezi, Ahmad, Dr. (Trans Tech Publications, 2014-01)In this project, iron mill scale has been used to produce iron powder that can be used within the Powder Metallurgy process. To achieve this objective, the iron mill scale needs to be refined. This involve the work of ... -
Tribological properties of WS2 nanoparticles lubricants on aluminum-silicon alloy and carbon steels
Riyadh A., Al-Samarai; Yarub, Al-Douri, Assoc. Prof. Dr.; Haftirman, Dr.; Khairel Rafezi, Ahmad, Dr. (Walailak University, 2013-06)The rheological properties of nanometric tungsten disulphide (WS2) nanoparticles oil lubricants and its tribological performance with two hypereutectic Al-Si alloy and carbon steel are examined. These two oils are used to ... -
Using gibbs standard state free energy and a power regulating device to predict and control the fabrication of nanoporous alumina
Alaba Oladeji, Araoyinbo; Azmi, Rahmat, Prof.; Mohd Nazree, Derman, Dr.; Khairel Rafezi, Ahmad, Dr. (VBRI press, 2013-12)The basic concept of Gibbs standard state free energy predicts a favorable condition for both room and high temperature fabrication of nanoporous alumina in phosphoric acid electrolyte. The anodization of aluminum foil in ...