bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Roughness Model for High Speed End Milling of Soda Lime Glass Using Carbide Coated Tools with Compressed Air Blowing
Authors: Mahmud M.A. , Amin A.K.M. Nurul , Arif Muammer Din
Published: October 2012

Glass materials play a vital role in advancement of science and technology. They have found wide spread application in the industry, in laboratory equipment and in micro-gas turbines. Due to their low fracture toughness they are very difficult to machine, moreover there are the chip depositions on the machined surface which affects surface finish under ductile mode cutting conditions. In this research, high speed end milling of soda lime glass is performed on CNC vertical milling machine to investigate the effects of machining parameters i.e. spindle speed, depth of cut, and feed rate on machined surface roughness. Design of experiments was performed following Central Composite Design (CCD) of Response Surface Methodology (RSM). Design Expert Software was used for generating the empirical mathematical model for average surface roughness. The model’s validity was tested to 95% confidence level by Analysis of Variance (ANOVA). Subsequent experimental results showed that the developed mathematical model could successfully describe the performance indicators, i.e. surface roughness, within the controlled limits of the factors that were considered.
Investigation of the Effects of Machining Parameters and Air Blowing on Surface Topography in High Speed End Milling of Silicon
Authors: Amin A.K.M. Nurul , Khalid Noor Syairah , Nasir Siti Nurshahida Mohd , Arif Muammer D.
Published: October 2012

Machining of silicon is an expensive affair because its inherent brittleness leads to subsurface crack generation. Research endeavours have therefore focused on ductile mode machining of silicon to obtain crack free machined surfaces with roughness as low as 0.22 µm or even below, hence eliminating the need for subsequent polishing/grinding operations. However, most of these research works utilized expensive ultraprecision machines and tools. This research aimed at determining the viability of using conventional milling machines with diamond coated tools, high speed attachments, and air blowing mechanisms in order to achieve ductile regime machining of silicon. Spindle speed, depth of cut, and feed rate, ranges: 60,000 to 80,000 rpm, 10 to 20 µm, and 5 to 15 mm/min respectively, were considered as the independent machining parameters. Compressed air at 0.35 MPa was also provided to prevent chip deposition on the finished surfaces. The resultant surfaces were analysed using Optical and Scanning Electron Microscopes. Then, the influence of each machining parameter on surface roughness was investigated. From the analyses it was concluded that all three machining parameters and air blowing had significant influence on the surface topography and integrity of silicon.
Optimization of Cutting Parameters in High Speed End Milling of Soda Lime Glass with Coated Carbide Tools Using Directional Compressed Air Blowing
Authors: Mahmud M.A. , Amin A.K.M. Nurul , Arif Muammer Din
Published: October 2012

An experimental study of high speed machining of soda lime glass using directional compressed air blowing for removal of the ductile chips from the machined surface, is presented. High speed end milling of soda lime glass is performed on a vertical CNC milling machine to observe the effects of machining parameters i.e. spindle speed, depth of cut and feed rate on the resultant surface roughness. The design of the experiments was performed following the Central Composite Design (CCD) of the Response Surface methodology (RSM) using the Design Expert Software. Optimization of machining parameters was conducted using desirability function of the Design Expert software based on minimum surface roughness criterion. Finally, experimental verification tests were conducted to validate the predicted optimized value.
Optimization of Surface Roughness in End Milling of Medium Carbon Steel under the Influence of Magnets Attached to the Machine Spindle
Authors: Amin A.K.M. Nurul , Akma Syidatul , Akma Maizatul , Arif M.D.
Published: October 2012

One of the major technological parameters in metal cutting is surface roughness. It is an unavoidable, and often, unwanted by-product of all machining operations, especially end milling. Surface roughness is directly related to product quality and performance, operation cost, machining accuracy, and chatter. Today’s stringent customer requirements demand machined parts with minimum (mirror finished) products. Hence, the prediction, modeling, and optimization of surface roughness is a quintessential concern in machining research and industrial endeavor. This research was undertaken in order to determine whether end milling of medium carbon steel performed using chosen ranges of cutting parameter and under magnetic field generated by permanent magnets could effectively improve surface roughness. A small central composite design with five levels and an alpha value of 1.4142, in Response Surface Methodology, was used in developing the relationship between cutting speed, feed, and depth of cut, with surface roughness. Design-Expert 6.0 software was utilized to develop the quadratic empirical mathematical model for surface roughness. The experiments were performed under two different conditions. The first condition was cutting under normal conditions, while the other one was cutting under the application of magnetic fields from two permanent magnets. Medium carbon steel was used as the work material. The resultant average surface roughness was found to be reduced by a maximum of 59% due to magnet application.
Surface Roughness Optimization in End Milling of Stainless Steel AISI 304 with Uncoated WC-Co Insert Under Magnetic Field
Authors: Amin A.K.M. Nurul , Sulaiman Syidatul Akma , Mohd Zainun Siti Noor Izzati , Arif M.D.
Published: October 2012

Chatter phenomenon is a major issue as it greatly affects the topography of machined parts. Due to the inconsistent character of chatter, it is extremely difficult to predict resultant surface roughness in a machining process, such as end milling. Also, recent studies have shown that chatter can be suitably damped using magnetic fields. This paper, thus, focuses on a novel approach of minimizing surface roughness in end milling of Mild (Low Carbon) Steel using uncoated WC-Co inserts under magnetic field from permanent magnets. In this experiment, Response Surface Methodology (RSM) approach using DESIGN EXPERT 6.0 (DOE) software was used to design the experiments. The experiments were performed under two different cutting conditions. The first one was cutting under normal conditions, while the other was cutting under the application of magnetic fields from two permanent magnets positioned on opposite sides of the cutter. Surface roughness was measured using Mitutoyo SURFTEST SV-500 profilometer. The subsequent analysis showed that surface roughness was significantly reduced (by as much as 67.21%) when machining was done under the influence of magnetic field. The experimental results were then used to develop a second order empirical mathematical model equation for surface roughness and validated to 95% confidence level by using ANOVA. Finally, desirability function approach was used to optimize the surface roughness within the limiting values attainable in end milling.
Efficient Cryogenic Cooling during Machining of Rolled AlSl 4340 Steel
Authors: Ahmed Mirghani I , Hrairi Meftah
Published: October 2012

Cryogenic cooling is an environmental friendly and effective cooling technology. The present work investigates the role of cryogenic cooling on tool wear at various cutting conditions. An indigenous method of applying cryogenic coolant was developed. Different methods of circulating the liquid nitrogen and vaporizing it inside the tool holder were tried with the objective of lowering down the temperature at the cutting zone. This was achieved through more efficient heat transfer. As-rolled AISI 4340 steel shafts were turned using coated cemented carbide inserts. Results of tool wear show improvement of tool life during cryo-machining as compared to dry machining especially when heavy depths of cut, high feed values and high cutting speeds are employed. The effect of cryogenic cooling was not pronounced at low speeds, small feed and depths of cut.
Optimization of Anode Usage in Electroplating Process by Using Response Surface Methodology
Authors: Begum Shahida , Tarlochan Faris , Sambasivam Kirubaharan
Published: October 2012

Electroplating is a process of depositing a layer of metal onto another base metal using the electrodeposition technique, where an acid is used as a medium of transferring the desired metal onto the base metal. During electroplating some amount of anodes are wasted and burnt and ended up not being used on the end product. A series of experiments with various input parameters were carried out in order to identify the best possible setting which would result in minimum anode usage. The experiments were designed using two level full factorial design. It was observed from factorial analysis that all the input variables like the porosity of anodes in anode basket, concentration of electrolyte and applied voltage have pronounced effect on the anode usage; however, the most significant influence was from porosity. The usage of the anodes was much less as the porosity due to the arrangement of anode in anode basket decreased. The interactive affects of the input variables such as the porosity and the voltage, and the porosity and the concentration were also prominent. The optimum operating conditions were identified by response optimizer plot and were verified experimentally. Both the analytical and experimental results indicated that anode usage could be reduced by 6.12% from that of the current practice. Hence it can be concluded that the operating variables in electroplating industry have significant effect on anode usage.
Effect of Die Modification to Geometrical Defect of Cold Forged AUV Propeller Blade
Authors: Abdullah A.B. , Sapuan S.M. , Samad Z. , Khaleed M.T. , Aziz N.A.
Published: October 2012

Accuracy and characteristics of the die and punch plays a significant role in the forming process. The perfectness of the die and punch will not guarantee that the part form as desired. Therefore, the die or punch needs to be modified. In practice, the modifications will be carried by trial and error based on the experience of the fabricator and the amount or removed section is unknown. In this study, the contribution of die modification to the geometric defect will be quantified by comparing the blade profile obtained from the nominal geometry of the blade and the profile constructed by commercial optical method namely Alicona system. For validation, Coordinate Measurement Machine was used
Development of Bio-Compatible Metallic Structures Using Direct Metal Deposition Process
Authors: Riza Syed H. , Masood Syed H. , Wen Cui'e , Song William
Published: October 2012

This paper investigates the capabilities of Direct Metal Deposition (DMD) process, which is a novel additive manufacturing technique, for creating structures that can be used as bone implants. Emphasis is on the use of bio-compatible metals, because metals are the most suitable materials in terms of mechanical strength when the requirement arises for supporting and replacing the load bearing bones and joints such as hip and knee. Specimens using two different metal powders, 41C stainless steel and Ti6Al4V titanium alloy, are generated by DMD process on mild steel and titanium plates as substrates respectively. Metallographic samples were made from the cladding, and tested for surface roughness and micro-hardness. The results indicate that at low laser power, hard and strong structures with good porosity can be successfully created using the DMD system.
Effect of Holding Time, Grain Size and Compacting Pressure Parameters against Compressive Strength of Aluminum - 5%Fly Ash
Authors: Seprianto Dicky , Firdaus Firdaus , Arifin Fatahul
Published: October 2012

This research is aimed to analysis the effect of holding time, grain size and compacting pressure parameter against compressive strength of Aluminum-5% fly ash using powder metallurgy method. The irregular form and homogeneous particles of aluminum powder used in this research is produced by Merck German, while fly ash is taken from residual combustion coal in forging process in mechanical engineering workshop of Politeknik Negeri Sriwijaya (Polsri) which is mashed up to grains size 140 and 270 mesh, pressed with holding time 60 and 120 seconds, with compacting pressure 139 N/mm2 and 275 N/mm2 by cold iso-static pressing. The green body resulted from these processes then sintered up to 550°C. Taguchi Method is used to determine factors which affect optimum condition of compressive strength of Aluminum-5% fly ash. The research result using ANOVA show that the holding time, grains size, , and compacting pressure parameters has significantly affect the compressive strength of Aluminum-5% fly ash.
Investigations on Metal Injection Molding of 316L SS Using Thermoplastic Natural Rubber (TPNR) Binder as a New System
Authors: Norita Hassan , Hassan Noor Azlina , Ahmad Sahrim H. , Muhamad N. , Omar Mohd Afian , Tarawneh Mou’ad A.
Published: October 2012

Metal injection molding (MIM) is a near net-shape manufacturing technology that is capable of mass production of complex parts cost-effectively. The unique features of the process make it an attractive route for the fabrication of the new binder system since the success of MIM process is dependent on the outward appearance of the resultant feedstock. Thermoplastic natural rubbers (TPNR) blends consist of thermoplastics, such as polyethylene (PE), alloyed with natural rubber (NR) with different thermoplastic to NR ratios. The soft grade TPNR is produced by blends with compositions richer in rubber while the harder grades can contain up to about 30 % NR. This study investigates the influence of new binder system consisting of TPNR on injection parameter, density of injected molded specimen and changes during solvent extraction. Results show that TPNR plays an important role as a good binder system and shortens the solvent extraction process.
Mixed-Flow Impeller Characteristics in Baffled Mixing Tank
Authors: Adeyemi Nabeel , Mohiuddin A.K.M. , Husaini Muhamad , Jameel Ahmad Tariq
Published: October 2012

In recent times, impellers have been designed and modified to combine unique hydrodynamic features to overcome redundancy during mixing. One of such impeller is the mixed-flow impeller which displays a unique combination of radial and axial flow. In this paper, the flow characteristic of a mixed-flow impeller is reported. The main focus is to compare the axial and radial characteristic of the velocity component using experimental and numerical study. The continuity and momentum equation were solved using the Reynold’s stress model (RSM). The field of view away from and below the impeller compared better with the numerical solution for the mean, radial and axial velocity component. Although the RSM was used at a higher computational cost, associated power number and energy of the impeller was also observed to be better predicted.
Rheological Behavior and Stability of Cassava Starch for Ceramic Mould Binder Application
Authors: Alias Tuti Yasmin , Idris Mohd Hasbullah , Zuraida Ahmad , Ourdjini Ali
Published: October 2012

Silica free binder was developed from cassava starch to correspond common ceramic mould binder for reactive metal casting application. Ceramic slurry rheology behavior and stability depends on both binder and refractory materials properties. Starch processing started from granule expansion or swelling, gelatinization, depolymerization via prolong heating and by adding plasticizer, citric acid is to improve viscosity. Pseudoplastic or shear thinning behavior for both binder and slurry were observed starting at 0.13 Pa.s and 2.5 Pa.s respectively. Calcium carbonate (aragonite) slurry from starch binder however, exhibited viscoelastic behavior compare to colloidal silica sol. Ceramic slurry aged as both cationic starch and CaCO3 flocculate and not exfoliate as indicated by increased in the pH of the slurry.
Optimizing Robotic Welding Parameter of Single Passed Butt Joint under Simultaneous Consideration of Multiple Response Using Multi Objective Taguchi Method
Authors: Abdul Rahim Mohammad Ridzwan , Manurung Yupiter H.P. , Jaafar Roseleena , Sunhaji K.A. , Tham Ghalib , Redza Mohd Ridhwan Mohammed , Lidam Robert Ngendang A. , Sulaiman Shahar , Noasiah M. , Amirul R.
Published: October 2012

This paper presents an alternative method to optimize parameters on single V butt welding. The effect of single-passed welding parameters such as current, voltage, welding speed and width of weaving movement on major welding defects by using a one-sided clamping method was investigated. The optimum parameter values were analyzed using Multi Objective Taguchi Methods (MTM) which started with the application of the common Taguchi methods (L8) Orthogonal Array (OA) and Total Normalized Quality Loss (TNQL) followed by ANOVA under simultaneous consideration of response weighting factors. Further, the value was analyzed by employing Multi Signal to Noise Ratio (MSNR). For the experimental study, a robotic welding system ABB IRB 2400/16 with digital welding power source KEMPPI Pro Evolution ProMIG 540 MXE with shielding gas Argon 80% and Carbon Dioxide 20% were applied. The material used is low carbon steel with 4 mm plate thickness. Based on the verification test result, it is found out that MTM can be used as an alternative method to investigate the optimum value of single passed welding parameter with multiple quality features.
Transversed Residual Stress Analysis on Multipassed Fillet Weld 2D-Using FEM and Experiment
Authors: Redza Mohd Ridhwan Mohammed , Manurung Yupiter H.P. , Lidam Robert Ngendang A. , Sulaiman Mohd Shahar , Rahim Mohammad Ridzwan Abdul , Yussoff Noor Syahadah , Tham Abdul Ghalib
Published: October 2012

In this project, the residual stress due to multipassed welding process at the fillet weld will be studied using 2D Finite Element Analysis (FEA) simulation method and experimental investigation. Due to the extensive capabilities and dedicated tools for the simulation of welding, including material deposit via element activation or deactivation and predefined or customized moving heat sources, SYSWELD 2010 was chosen as the FEA software. The material with a thickness of 9 mm was structural steel S355J2G3 for simulation and low carbon steel for the experiment. The clamping condition was selected to obtain the best relationship between simulation and experiment by using Strain Gage. The model was dedicated to multipassed welding using the robotic welding system
Predicting Bead Geometry of 2F-Fillet Joint Welded by Small Wire SAW
Authors: Ahmad Hamidi Shahfuan Hanif , Tham Abdul Ghalib , Manurung Yupiter H.P. , Abas Sunhaji Kiyai
Published: October 2012

The cost of development of WPS will be very expensive if the welding parameter is selected based on trial and error. Optimal welding condition cannot be easily guessed unless the operator has records of good welding. If a calculator that can predict the welding parameter for the desired bead geometry accurately, such tool will be extremely useful for any fabrication industry. This paper intends to investigate the correlation between the welding parameter and weld bead geometry of 2F position T-fillet carbon steel, when welded by 1.2 mm diameter wire submerged arc welding. Keeping only one parameter as variable, 2F fillet weld coupons are welded by SAW with a range of welding current, welding voltage and welding speed. Only weld bead geometry that complied with the quality requirement of code of practice AWS D1.1 is considered. The trendline graph is created to fit the correlation between the heat input and the fillet weld geometry. By incorporating the trendline formulas into the calculator, the weld bead geometry can be predicted accurately for any welding parameter. The mean absolute deviation (MAD) between the predicted geometry and the experimental results is less than 0.50mm.
Investigation on Weld Induced Distortion of Butt Joint Using a Local/Global Simulation Approach
Authors: Sulaiman Mohd Shahar , Manurung Yupiter H.P. , Ridhwan Mohd Redza , Robert N.L. , Ridzwan M.A.R. , Hazwan M.H. , Haruman E. , Sunhaji K.A. , Ghalib T.
Published: October 2012

In this paper, a local/global approach has been used to predict weld induced distortion in butt joint. This approach combines non-linear thermo-elastic plastic and linear elastic analyses to compute final distortion triggered by the welding process. Distortion can lead to dimensional inaccuracy and thus causing the rise in fabrication cost. In this study, Finite Element Method (FEM) software Sysweld and Pam-Assembly were used for computing the welding deformation. The material used for the simulation was low carbon steel with thickness of 4 mm. Based on the result obtained, it was observed that this approach provides fast computation time and efficient solution.
Characterization of Forsterite Bioceramics
Authors: Lee K.Y. Sara , Chin K.M. Christopher , Singh Ramesh , Tan Chou Yong , Teng Wan Dung , Sopyan Iis
Published: October 2012

The present work is on the synthesis of forsterite (Mg2SiO4) powder using talc and magnesium oxide powders as the starting materials followed by a heat treatment process. Sintering behavior and mechanical properties of the forsterite bodies were evaluated from 1200°C to 1500°C. Forsterite phase were detected in samples without any secondary phases at all sintering temperatures. A very high fracture toughness of 4.9MPa.m1/2 and Vickers hardness of 7.1GPa were measured for samples sintered at 1400°C, thus indicating the viability of this ceramic for biomedical application.
Effect of Sintering Time on Silver-Aluminium Nanopaste for High Temperature Die Attach Applications
Authors: Manikam Vemal Raja , Khairunisak Abdul Razak , Cheong Kuan Yew
Published: October 2012

Nanoscale materials, primarily metallic elements have been proven as suitable solutions for interconnect technology on power semiconductor devices. Nanoscale materials possess high surface energies thus enabling them to be processed at lower temperatures for high temperature applications of more than 500°C. This literature work aims to present a novel silver-aluminium (Ag-Al) nanoalloy die attach paste solution for power semiconductor devices. Ag and Al nanoparticles were pre-mixed into an organic paste system using binders and a surfactant. Viscosity tests concluded that the Ag-Al nanopaste is suitable for mass manufacturing dispensing and screen printing with an average value of 47,800 cps. Thermogravimetric analysis was used to design the sintering profile at 380°C from 10 to 30 minutes. X-ray diffraction analysis detected the formation of Ag2Al and Ag3Al compounds in the post-sintered nanopaste. Scanning electron microscopy and Energy-dispersive X-ray spectroscopy showcased larger grains in the nanopaste microstructure with the passage of sintering time. The electrical conductivity of the Ag-Al nanopaste decreased as the stencil printed paste thickness increased between 25.4-101.6 microns. This was due to the much larger pore formation in the thicker nanopaste layers during sintering and organics burn off.
Development of Cu-SiC Composite for Electrical Discharge Machining Electrode Using Powder Metallurgy Technique
Authors: Azreen A.R. Fatimah , Sutjipto A.G.E. , Souad A.M. Al-Bat’hi
Published: October 2012

In this research, composites containing 10-50 vol% SiC whiskers reinforced Cu matrix were fabricated using powder metallurgy technique. The mixtures were blended in a ball milling machine with the addition of ethanol for 2 hours at 150 rpm. The mixtures were allowed to dry in an oven at temperature of 40 °C. Then, the mixtures were uniaxially compacted into a cylindrical pallet of Φ 13.5 x 2 mm under compaction pressure of 472 MPa. It was followed by sintering in vacuum furnace at temperatures of 800-950 °C for 4 hours. The density, microhardness, electrical resistivity, thermal conductivity and microscopy analysis of the sintered composites were studied and reported in this paper.
Effect of Bead Size on Fineness of Centella asiatica (C. asiatica) Particles in Wet Grinding
Authors: Borhan Muhammad Zuhairi , Norhidayah Abdullah , Nurulhuda Ismail , Ahmad Rohaya , Rusop Mohammad , Abdullah Saifollah
Published: October 2012

Nanoparticles are now essential material to be used in material engineering, medicine and cosmetic application due to their chemical, mechanical and optical properties. Several experiments were designed to investigate the relationship effect of bead size using different bead size (4 mm and 2 mm) at fix grinding conditions. Changes in particles size produce were studied using dynamic light scattering method at 25 °C. The z-Average and polydipersity index for each particles size at different grinding were recorded. Using smaller size of zirconia bead will produced smaller size of C. asiatica than using larger bead size. As a result the smallest size particle by mean is 242 nm where 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition at 517 nm shows the smaller particles has a higher percentage of inhibition.
Mechanical Properties Investigation of HIP and As-Built EBM Parts
Authors: Hosseini Afshin Mohammad , Masood S.H. , Fraser Darren , Jahedi Mahnaz
Published: October 2012

Electron beam melting (EBM) is a direct metal additive manufacturing technique which has been recently utilized for fabrication of biomedical implants. This paper represents an investigation into the mechanical properties of both as-built and hot isostatic pressing (HIP) processed samples manufactured in EBM process. The titanium alloy, Ti6Al4V was used, which is one of the most common materials for biomedical implants due to its high strength to weight ratio, corrosion resistance, and its biocompatibility features. Tensile properties, surface roughness, and Vickers microhardness have been investigated.
The Effect of Milling Speed and Calcination Temperature towards Composite Cathode LSCF-SDC Carbonate
Authors: Ahmad S. , Bakar M.S.A. , Muchtar A. , Muhamad N. , Rahman H.A.
Published: October 2012

The effects of milling speed and calcinations temperature towards La0.6Sr0.4CO0.2Fe0.8O3-δ-SDC carbonate (LSCF-SDC carbonate) composite cathodes were investigated. The preparation of samarium-doped ceria (SDC) carbonate was firstly done by milling the SDC nanopowder with carbonate using the high-energy ball milling (HEBM) in air at room temperature. The obtained SDC carbonate was then used to mill with composite powder of lanthanum strontium cobalt ferrite (LSCF) which is one of the promising materials for the cathode of solid oxide fuel cells (SOFC). The purpose of milling LSCF composite powder with SDC carbonate was to get new composite cathode for intermediate-to low-temperature solid oxide fuel cells (IT-TLSOFC). LSCF composite powder with SDC carbonate was milled using high-energy ball milling with milling speed of 150 rpm and 550 rpm and calcinations temperatures of 750°C, 800°C, 850°C and 900°C. Field emission scanning electron microscopy (FESEM) analysis revealed the presence of large particle resulting from the increasing of calcinations temperature. FESEM also shows the particle size decrease in size with the increasing of milling speed. Therefore, the speed of 550 rpm and temperature of 900°C were found to be the best milling speed and calcinations temperature in producing the composite cathode of LSCF-SDC carbonate.
Dynamic Mechanical Behaviour of Poly Ethylene Glycol Plasticized Polylacticacid
Authors: Kaiser M.R. , Anuar Hazleen , Razak Shamsul Bhari A.
Published: October 2012

Polylacticacid (PLA), produced from annually renewable, natural resources is a potential candidate for the partial replacement of petroleum based polymers and also for its biodegradability. PLA is well known for its better mechanical, thermal property but unfortunately the brittleness and rigidity limit its applicability. For a great number of applications such as packaging, fibers, films, etc., it is of high interest to formulate new PLA grades with improved flexibility and better impact properties. In order to develop PLA-based biodegradable packaging, the physico-mechanical properties of commercially available PLA should be modified using plasticizers. For this, PLA was melt-mixed with poly ethylene glycol (PEG) of 600 molecular weights by twin screw extruder. The thermal properties of plasticized PLA were characterized by utilization of dynamic mechanical analysis. The result shows that with addition of plasticizer glass transition temperature (Tg) is decreased sharply and the storage modulus was also decreased.
Mechanical and Electrical Properties of Y-TZP/ZrB2 Composite
Authors: Amiriyan M. , Chew W.J. Kelvin , Singh Ramesh , Tolouei R. , Hassan M.A. , Hossain A. , Sopyan Iis , Meenaloshini S.
Published: October 2012

Over the last three decades, most of the efforts in mechanics of materials science have been focused to develop tougher and stronger ceramics via cost effective processing techniques. In the present work, 3 mol % Yttria-stabilized tetragonal zirconia (3Y-TZP) composites with 25 wt. % of ZrB2 was prepared by pressureless sintering method in argon atmosphere over the temperature range of 1350-1550°C for one hour holding time. The influences of zirconium diboride addition in the zirconia matrix, as well as the sintering temperature, on the densification, phase stability and electrical properties of sintered samples have been studied. The results revealed that electrical resistivity values is very low (high electrical conductivity) when 25 wt. % of ZrB2 is incorporated to pure 3Y-TZP.
A New Experimental Approach to Determination of Critical Depth in High Speed Machining of Soda-Lime Glass
Authors: Mahmud M.A. , Amin A.K.M. Nurul , Arif M.D.
Published: October 2012

Soda-Lime glass is a very hard and brittle material which is commonly used as window panels and many other common applications. Due to its low fracture toughness it is very difficult to machine and obtain good surface finish under nornal cutting conditions. Hence, machining has to be done in ways to avoid brittle fracture on the finished machined surface. Such machining is only possible under ductile mode machining conditions when the removal of material is performed in the plastic state. However, ductile mode machining requires that during machining the temperature generated in the cutting zone in the working temperature range of glass to avoid crack formation during machining. This makes all types of machining of glass an extremely challenging affair, given the current state and mode of mechanical machining. This research paper elucidates the results of an experimental study for determination of critical depth of cut as a function of cutting parameters in high speed end milling of soda-lime glass. The critical depth is defined as the depth of cut at which crack formation the material is initiated for a given high speed attachment. In determining the critical depth as well as the ductile brittle transition depth, machining was performed on a tapered surface. Vibration signals from an accelerometer in time domain (amplitude vs. time display) and the surface characteristics were used in identifying the critical depth of cut. The new method has been found to be useful in online determination of the critical depth, as well as the brittle-ductile transition depth, for generating crack-free surfaces with good surface finish in high speed end milling of soda lime glass.
Experimental Study on Jute-Fiber-Epoxy Composite Plate Subjected to Impact Loading
Authors: Omar Nurihan , Mohd S. Najwa S. , Aminanda Y. , Ali J.S. Mohammed , Kashif S.M.
Published: October 2012

World is currently focusing on alternate material sources that are environment friendly and biodegradable in nature. Due to the increasing environmental concerns, bio-composite made from natural fibers and polymeric resin, is one of the recent developments in the industry and constitute the present scope of experimental work. This work presents on advantages, mechanical and physical behavior of jute fiber – epoxy composites, one of the renewable alternatives. The bio-composite is experimentally investigated in term of low velocity impact loading. The experimental observations in term of damage mechanism, maximum force and maximum energy absorption were studied to understand the effect of fiber orientation. A comparative study with typical synthetic fibers like carbon and glass were also conducted.
Polyurethane/Clay Shape Memory Nanocomposites Based on Palm Oil Polyol
Authors: Zubir Syazana Ahmad , Ernie Suzana Ali , Ahmad Sahrim Haji , Muhammad Zain Norazwani , Wai Soo Kai
Published: October 2012

Thermoplastic polyurethane (TPU) nanocomposites were prepared using polycaprolactonediol as the soft segment, 4,4’-diphenylmethane diisocyanate as the hard segment, 1,4-butanediol and palm oil polyol. Nanoclay with certain weight percent (wt%) was reinforced as filler to improve both mechanical and shape memory behavior of the nanocomposites. Palm oil polyol was introduced in order to provide hyperbranched structure for better dispersion of filler in the matrix as well as aiding the crosslinking process. The experimental results showed that the mechanical and shape memory behavior of clay reinforced polyurethane nanocomposites were influenced by clay weight percent in the polymer matrix. TPU with 3 wt% clay showed optimum values of mechanical properties while the shape memory behavior decreases with increasing clay content.
Shifting of X-Ray Diffraction Pattern Peak on BaFe12O19 Nanocrystalline Produced by Sol Gel Auto Combustion Method
Authors: Suastiyanti Dwita , Soegijono Bambang
Published: October 2012

Barium hexaferrite BaFe12O19 (BHF) is one of the great importance as permanent magnets, particularly for recording magnetic in microwave devices. Nanocrystalline BHF powders were prepared by sol gel auto combustion method in citric acid – metal nitrates system. Hence the mole ratios of Ba2+/Fe3+ were varied at 1:12; 1:11.5 and 1:11 and with pH of 7 in all cases using amonia solution. For final formation of nanocrystalline BHF, heating process was done at 850oC for 10 hours in all mol ratios of Ba2+/Fe3+. The nanocrystallite size was calculated from broadening X Ray Diffraction (XRD) peaks using Scherrer formula. XRD data shows that BHF of ratio 1:12 has the same diffraction pattern with the ratio of 1:11 especially at higher value of 2 θ. Diffraction pattern of BHF with the ratio of 1:11.5 was fitting in exactly to the standard searching match and the highest value of best Figure of Merit (FoM) is 90% with the crystallite size of 22 nm. The best FoM and crystallite size for ratio of 1:12 and 1: 11 are 88% and 56 nm respectively. The diffraction peaks of BHF with the ratio of 1:12 and 1:11 are in the right side from of 1:11.5 since the amount of impurity of both is higher (12%) than of BHF with the ratio of 1:11.5 (10%).
Evaluation of Maximum Percentage Glucose Conversion for Dilute Acid Hydrolysis of Kenaf Biomass Using Statistical Analysis
Authors: Nur Aimi M.N. , Mohd Adlan Mustafa Kamalbhrin , Nurhafizah Seeni Mohamed , Ahmad Fitrie Mohd Ithnin , Anuar Hazleen , Mel Maizirwan , Othman Rashidi
Published: October 2012

Kenaf (Hibiscus cannabinus.L) is a crop- that produces about 70% of biomass larger than any of forest plantations. There is no specific way of using kenaf biomass in industry instead for animal feed and burning in various forms (waste in general). As a result, several researches had been conducted to utilize it in the production of biodegradable polymer as well as bioethanol. This is due to its complex cellulose content that is useful to be converted into glucose before further process. The conversion step from cellulose content of kenaf biomass into glucose is known as pre-treatment process. In this paper, dilute acid hydrolysis was chosen as the pre-treatment process. With the aim to evaluate the maximum percentage of glucose conversion for this kind of pre-treatment process from kenaf biomass, statistical analysis which is analysis of variance (ANOVA) design via central composite design using response surface method (RSM) was selected. Thus, the lower the mass which is at 2 g, and at higher temperature which is 180 oC in longer time which is in 60 min results about 25.33% glucose conversion with the comparison of the predicted value obtained from the experimental design.
Production of Lactic Acid from Kenaf Core Hydrolysate by Rhizopus oryzae FTCC 5215
Authors: Nurhafizah S.M. , Anuar Hazleen , Mel M. , Othman Rashidi , Nur Aisyah M.N. , Nur Aimi M.N.
Published: October 2012

Lactic acid (LA) is commercially produced biologically using food-derived raw materials such as potato and corn. It seems to be less economical since they have to compete with the food sources industries. Thus, kenaf (Hibiscus cannabinus) is found to be the best alternative to substitute the raw material for LA production. In this paper, kenaf core were used as the substrate for production of LA by Rhizopus oryzae FTCC 5215. Since kenaf is one type of lignocellulosic material which is naturally resistant to breakdown to its structural sugars, it will inhibit microorganisms to be accessed through. Thus, hydrolysis process is needed as the aid for the liberation glucose. The highest value of lactic acid produced is 15.2 g/L at 25 oC with speed 200 rpm.
Application of Taguchi's Approach in the Optimization of Tensile Properties of Epoxy/Nanoclay/MWCNT Nanocomposites
Authors: Ku Ahmad Ku Zarina , Ahmad Sahrim Haji , Tarawneh Mou'ad A. , Rasid Rozaidi , Apte Prakash R.
Published: October 2012

This paper reports the improvement in tensile strength of epoxy by using binary hybrid nanocomposites of nanoclay and multi-wall carbon nanotube using a solution casting method. The effect of clay/MWCNT ratio, types of solvent, clay cation, composition of LENR, cure time and cure temperature on the tensile properties of epoxy nanocomposites were investigated using Taguchi Method. Orthogonal array L27 is chosen for sample preparations. Analysis of Mean (ANOM) and Analysis of Variance (ANOVA) was used to identify the dominant factors and the optimum values of clay/MWCNT ratio and settings of other process parameters. Confirmation of experiment was performed with the optimum parameter settings and the measured mechanical properties were compared with the predicted results. Morphologies of the fracture surface of MWCNT/epoxy nanocomposites was observed by scanning electron microscope (SEM). Transmission electron microscope (TEM) and X-ray diffraction (XRD) test were employed to analyse the dispersion structure in the modified samples.
Structural Development of Expanded Austenite on Duplex Stainless Steel by Low Temperature Thermochemical Nitriding Process
Authors: Paijan L.H. , Berhan M.N. , Adenan M.S. , Yusof N.F.M. , Haruman E.
Published: October 2012

This paper describes the results of gaseous thermochemical treatment of nitriding duplex stainless steel using tube furnace. The nitriding was performed in temperature range between 400°C and 500°C for 6 hours, forming a dual layer structure with hard nitrogen layer. The nitriding gas composition used for this process is 50% NH4 + 50% N2 and 25% NH4 + 75% N2. The structural development was characterised using hardness tester, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Based on the experimental results, it was found that nitrided layer produced maximum thickness nitrided layer about 13.96µm and hardness 666.3 HV0.025 at 450°C with 50% NH4. The formation of expanded austenite was observed in temperature range between 400°C and 500°C. However, the cromium nitride has been developed at temperature 500°C which decreased the corrosion properties of duplex stainless steel.
Effect of Silver Colloid on Chemical and Physical Properties of Cotton Fabric for the Application of Antimicrobial Textiles
Authors: Arain Rabia Almas , Khatri Zeeshan , Memon Muhammad Hanif
Published: October 2012

We report an application of silver colloid on cotton textile using a one- step method. Cotton fabric was treated with silver colloid and antimicrobial activity against Staphylococcus Aurous (gram positive) and Escherichia coli (gram negative) bacteria were evaluated. The treated fabric was evaluated in terms of physical properties such as tensile strength and stiffness, wrinkle recovery angle and degree of whiteness was evaluated. The change in chemical structure and morphology were evaluated using FTIR and SEM respectively. The study revealed that the maximum antimicrobial activity was obtained at 2.5 % of silver colloid while the 3 minutes cure of the treated cotton provided a better overall performance in terms of antimicrobial activity and physical properties.
Statistical Approach to Modeling & Optimization of Surface Roughness in High Speed End Milling of Silicon with Diamond Coated Tools
Authors: Amin A.K.M. Nurul , Khalid Noor Syairah , Nasir Siti Nurshahida Mohd , Arif Muammer D.
Published: October 2012

This research demonstrated the use of conventional milling machines with diamond coated tools, high speed attachments, and air blowing mechanisms for ductile mode machining of silicon and subsequently modeling and optimizing the resultant surface roughness. Spindle speed, depth of cut, and feed rate, ranges: 60,000 to 80,000 rpm, 10 to 20 µm, and 5 to 15 mm/min respectively, were considered as the independent machining parameters for the modeling process. Compressed air at 0.35 MPa was also provided to prevent chip deposition on the finished surfaces. The resultant surfaces were analysed using Optical and Scanning Electron (SEM) Microscopes as well as Wyko NT 1100 and SurfTest SV-500 profilometers. The response, surface roughness, was then modeled using a small Central Composite Design (CCD) in Response Surface Methodology (RSM). The quadratic relation was found to be most suitable following Fit and Summary and ANOVA analyses. The relation was then optimized using Desirability Function (DF) in Design of Expert (DOE) software. The optimum attainable surface roughness, which was validated using experimental runs, was found to be 0.11 µm which may be considered quite satisfactory.
Effect of Fibre Size on the Tensile Properties of Oil Palm Empty Fruit Bunch Fibre Composites
Authors: Abdul Razak Noorrul Wahida , Kalam Anizah
Published: October 2012

The principal aim of this project was to achieve a better understanding of the various parameters that contribute to the tensile properties. These parameters were manipulated in order to improve and produced PPnanoclay/ Polypropylene (PP) reinforced oil palm empty fruit bunch composite material (OPEFB). OPEFB fibre was treated with sodium hydroxide (NaOH) in order to improve the tensile properties of the composites. Thus, in this study the oil palm empty fruit bunch fibres were used as a filler and PPnanoclay/ PP composite as the matrix material. Tensile test was used to assess the effect on the tensile strength and tensile modulus of OPEFB/PPnanoclay/PP composites. Morphologies of the composites were examined using a scanning electron microscope (SEM). The average tensile properties obtained were tensile strength 22 MPa at 180 µm and Young’s modulus 2120 MPa at 355 µm treated.
An Assessment of the Physico-Chemical Properties of Melon Seed (Citrullus lanatus) Oil as Base Material for Oil-in-Water Emulsion Cutting Fluid
Authors: Lawal Sunday Albert , Choudhury Imtiaz Ahmed , bin Yusoff Nukman
Published: October 2012

The study highlights melon seed oil as possible cutting fluid for machining processes. The properties of melon seed oil were investigated. Formulation of oil-in-water with addition of some additives was carried out and the results obtained suggest that melon seed oil possesses the relevant properties as a base material for oil-in-water emulsion cutting fluid.
The Study of Surface Roughness and MRR of Mild Steel Using Manual Plasma Arc Cutting Machining
Authors: Bhuvenesh R. , Abdul Manan M.S. , Norizaman M.H.
Published: October 2012

Manufacturing companies define the qualities of thermal removing process based on the dimension and physical appearance of the cutting material surface. Therefore, the roughness of the surface area of the cutting material and the rate of the material being removed during the manual plasma arc cutting process was importantly considered. Plasma arc cutter Selco Genesis 90 was used to cut the specimens made from Standard AISI 1017 Steel manually based on the selected parameters setting. Two different thicknesses of specimens with 3mm and 6mm were used. The material removal rate (MRR) was measured by determining the weight of the specimens before and after the cutting process. The surface roughness (SR) analysis was conducted to determine the average roughness (Ra) value. Taguchi method was utilized as an experimental layout to obtain MRR and Ra values. The results reveal that for the case of manual plasma arc cutting machining, the SR values are inversely proportional to the MRR values. The quality of the surface roughness depends on the dross peak that occurred during the cutting process.
Evaluation of Wrinkle Recovery Angle & Color Fastness Properties of Ionic Crosslinked Hospital Green Vat Dyed Cotton Fabric
Authors: Saleem Umaima , Khatri Zeeshan , Memon Muhammad Hanif
Published: October 2012

Cellulose cross linking is a very important textile process and has application in the crease resistant finished textile products. N-methylol cross linkers give fabrics desirable mechanical stability properties, but also reduces strength and release formaldehyde, a known human carcinogenic. Our work is based on reactions of particularly hospital green vat dyed cellulose with materials that creates an ionic character to the cellulose. These reactions produce ionic cellulose that can react with a poly ionic material of opposite charge to form cross links. The ionic content of the fabric and various features of the application procedure were varied to optimize the results.
Influence of MgO Molar Concentration to the Properties of Multilayer ZnO/MgO Films Using Sol-Gel Method
Authors: Habibah Zulkefle , Rahman N.S. , Wahid M.H. , Ismail L.N. , Bakar Raudah Abu , Mamat M.H. , Rusop Mahmood Mohamad
Published: October 2012

Multilayer ZnO/MgO was successfully deposited using sol-gel spin coating method at different MgO molar concentration. The electrical and dielectric properties of deposited multilayer films were investigated using two point probes I-V measurement and impedance spectroscopy respectively. The resistivity was calculated based on I-V curve obtained and the results show that there is increment in resistivity values from 1.04 x 105Ω.cm to 7.45 x 105Ω.cm as the MgO concentration varied from 0.2M to 1.0M. The growth of multilayer films was measured in term of their thickness using surface profiler. Moreover from the observation, the value of dielectric constant, k is decrease when the MgO concentrations increase due to non-uniform and porous structure in the films. This is proven by their surface morphology observed by field emission scanning electron microscopy, FESEM. There is also interesting view obtained in this work where the surface morphology of multilayer film with 0.2M and 0.4M MgO concentration produced nano-flower and nano-rod like structure respectively.
Impact of Chemical Modification on the Physical and Mechanical Properties of Tropical Wood Material
Authors: Hamdan Sinin , Islam M. Saiful
Published: October 2012

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.