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The issue related to disposing the waste material from the industries becomes one of a major problem to the environmental, economic, and social issue. However, natural resources consume worldwide, while at the same time increased amount and type of waste material has resulted in a waste disposal crisis with a growing consumer population. In this project, Municipal Solid Waste Incineration (MSWI) by-product which is bottom ash and rice husk ash were used as blended cement. This research paper is prepared to investigate the utilization of municipal solid waste incineration bottom ash in blended cement and designed for the strength of 15 MPa at 28 days will be evaluated for its early-stage properties. Rice husk ash is used to reduce the amount of cement in mortar and it helps to increase the durability of mortar while keeping up consistent workability. The percentage of replacement in cement is by 0% (control), (5% rice husk ash + 10% bottom ash), (10% rice husk ash + 10% bottom ash), and (15% rice husk ash + 10% bottom ash) The result of this research indicates that 5% of replacement of rice husk ash with 10% of bottom ash shows highest compressive strength with 17.79 MPa with density 2080 kg/mɜ and water absorption of 5.18% at 28 days. This study proved that the addition of bottom ash can increase the durability, workability, and strength of mortar containing rice husk ash as a replacement for cement.

LiV3O8 layered structure was successfully synthesized by a conventional solid-state approach and subsequent heat-treated at 400, 450, 500 and 550 oC. The samples were characterized by XRD, SEM, TEM, BET. Electrochemical performance of LiV3O8 was investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge. The results showed that high purity of LiV3O8 with layered structure was formed. The morphology of the samples were mixed between nanorods and nanosheets structure. For electrochemical performance, results showed that LiV3O8 heat-treated at 500 oC performed a highest charge and discharge capacity of 212 and 172 mAh g-1, respectively. From electrochemical performance results made them a good candidate for cathode material for lithium-ion batteries application.

Powder metallurgy technique were proved successful net-shape technology which suitable for the production of green glass ceramic (GGC) from rice husk ash (RHA) and characterized by good physical and mechanical properties of glass ceramic. In this research, the glass sample was formed by mixing varying percentage of weight of silica, flux and additives. The aim of this work is to study the effect of the sintering temperature to the physical and mechanical properties of GGC. The samples were mixed in different volume fraction of additives which is 5%, 10% and 15% in constant composition of RHA and flux. The mixture was consolidated into rigid die compaction at 300MPa, then sintered at 450, 550 and 750°C. Vickers hardness test were investigated. The glass composite were then characterize by scanning electron microscopy (SEM). The GGC with 10% additives at sintering temperature 550°C shows highest hardness strength which is about 213.0 HV.

Layered nanosheets of a LiV3O8 cathode material were successfully prepared via a modified solid-state synthesis. The morphological changes of the layered nanosheets of the LiV3O8 cathode, which resulted from preparation at different temperatures, strongly affected the electrochemical performance of this cathode material. The layered nanosheets of the LiV3O8 cathode prepared at 500 °C delivered the highest electrochemical performance with initial charge and discharge capacities of 212 and 175 mAh g−1, respectively, when cycled between 1.5 and 4.0 V versus Li/Li+. The particulate morphology of LiV3O8 showed widths in a range of 100-145 nm and lengths between 1.0 and 2.5 µm. The layered nanosheet structure contributed to the increased electrochemical performance of LiV3O8 as a cathode material for applications in high-energy lithium-ion batteries.

Trabecular bone fractures heal through intramembranous ossification. It is a highly porous biological tissue with an open-celled cellular structure, which accounts for up to 20% until 60% of the bone mass in humans for healthy bone while about 80% for an osteoporosis case. In bone healing, there is very little callus formation, woven bone forms directly without a cartilage intermediary, and the woven bone is remodelled to form trabecular bone. Trabecular bone has less mineral and porosity percentages compared to the compact bone. Thus, the stress distributions around the screw were affected by the amount of the porosity within the trabecular bone. In bone healing mechanism, stability may speed up the bone healing process. The interface contact between external fixator pins and screws of internal fixator influence the fixation stability for bone healing. This study aims to investigate the amount of stress distribution on the around screw implant through the trabecular bone porosity condition under pull out loading. Finite element analysis is employed to simulate the stress distribution associated to the screw implant and cortical-trabecular interface As a result, the area of screw head is found to be yielded as the porosity of trabecular bone is considered.

Visual defects detection is one of the main problems in the post-harvest processing caused a major production and economic losses in agricultural industry. Manual fruits detection become easy when it is done in small amount, but the result is not consistent which will generate issue in fruit grading. A new fruit quality assessment system is necessary in order to increase the accuracy of classification, more consistencies, efficient and cost effective that would enable the industry to grow accordingly. In this paper, a method based on colour feature extraction for the quality assessment of Harumanis mango is proposed and experimentally validated. This method, including image background removal, defects segmentation and recognition and finally quality classification using Support Vector Machine (SVM) was developed. The results show that the experimental hardware system is practical and feasible, and that the proposed algorithm of defects detection is effective.

In this paper, the effect of catalyst, Na2SO4 and temperature on carbothermal reduction and nitridation of Langkawi black sand was investigated. Reduction was performed under 100% nitrogen gas (N2) with a temperature range of 1200 °C - 1400 °C for 3 hours soaking time respectively. Four different amount of catalyst, Na2SO4 range from 0% to 15% were investigated in the reaction. By adding of Na2SO4, it is slightly down the reaction temperature from 1400 °C to 1200 °C by using at least 10% of catalyst. Catalyst, Na2SO4 assist the formation of titanium oxycarbonitride (TiOXCyNz) but the concentration of impurities not affected by catalyst. The XRD pattern indicate that titanium oxycarbonitride phase with the composition of TiO0.19C0.53N0.32 at 1400 °C detected from 0%-15% of catalyst. From XRD pattern, increasing the reduction temperature, will increase the formation of titanium oxycarbonitride. With addition of catalyst, the microstructure of the iron particles coarsened whereby this coarsening is important to increase the reduction of ilmenite and titania.

For centuries, the finite element (FE) method has been extensively used to predict the fracture performance and various method has been implemented to yield accurate results especially in healthcare industries. Bone fracture has been a critical problem since it interrupts the strength and structure of human bone. Thus, this problem will lead to bone malfunction and cause excess bleeding of surround tissues. Human bone consists of cortical and trabecular bone which serve a different amount of load sustainability before the fracture occurred. One of the most vital problems arise is the inaccuracy of the stress intensity factor related to the bone fracture. Recent studies have proven that with the implementation of appropriate meshing element produce higher accuracy results especially with the implementation of mesh refinement in the finite element model. The singularity elements suggested by Barsoum (1976) has proven that the quarter-point triangular elements give highly accurate results. Several methods for stress intensity factor calculation has been implemented by various past researchers. Among all the methods used, J-integral has proven to be the most accurate method compared to the others. The first section in your paper.

Powder metallurgy metal matrix composites based on AZ91 alloy matrix reinforced with 0.3, 0.6 and 0.9 weight percent of multiwall carbon nanotube (MWCNT) were investigated from the point of view of their response to artificial ageing as compared to the unreinforced AZ91 matrix alloy. Mg-Zn-Al (AZ91) and its composite were prepared by milling the raw materials and followed by sintering at 450°C for 2 hours. The sintered samples were solution treated at 415°C for 2 hours and followed by artificial ageing at 175°C. The ageing behavior was monitored by following the phase analysis and hardness of the samples examined. Microstructure of the sintered composites indicated that MWCNT was embedded in the AZ91 matrix alloy. All composites indicated lower hardness than matrix, however AZ91reinforced with 0.6 and 0.9 weight percent of CNT showed accelerated ageing. X-ray diffraction pattern indicated the present of β-phase (Mg17Al12) that responsible for the hardening behavior.

Hybridization of multi wall carbon nanotubes (MWCNTs) with other filler in polymer matrix composites (PMC) is one of the techniques for combining different properties of fillers for making more unique composites. In this work, the hybrid filler (CNTs–dolomite) are prepared via chemical vapour deposition (CVD hybrid) and the milling method (physically hybrid). The effect of different hybrid method on properties of multi wall carbon nanotubes/dolomite hybrid filled phenolic composites were studied. Phenolic/CVD hybrid composites and phenolic/physically hybrid composites with different filler loadings were prepared using hot mounting press. The prepared samples were characterized for their thermal conductivity and hardness. The thermal conductivity was measured using the Transient Plane Source (TPS) method, using a Hot-DiskTM Thermal Constant Analyzer and the hardness was measured using Rockwell micro-hardness. The results showed that at 5% filler loading, the phenolic/CVD hybrid composites were capable of increasing the thermal conductivity and micro-hardness up to 7.22% and 101.6% respectively compared to pure phenolic.

Visual appearance is the main source of information that can be used for quality assessment of mango. In this study, a non-destructive ripeness level estimation for mango of the cultivar Harumanis based on digital image analysis was employed. The changing peel and flesh colour of mango is strongly correlated to ripeness that can be measured as a sensual quality parameter. This measurement of ripeness level has been determined by image analysis technique which needs to attribute external and internal colour feature from image segmentation Multilevel thresholding technique is proposed for colour image segmentation to extract the mango region from the background which every channel of five colour spaces have been applied. Colour analysis technique and Total soluble solids (TSS) is used to compare and evaluate for the prediction. The optimal results were obtained that a* channel from L*a*b colour space has given more logical and better performance of prediction which is more than 92% accuracy.

In the present work the effect of heat treatment on the hardness behavior of AZ91 and AZ91 reinforced carbon nanotube were investigated under FESEM, Xrd and Rockwell hardness tester. Cnt was embedded homogenously into the matrix due to successfully mechanical alloying using planetary milling. Kinetic precipitation of β-phase (Mg17Al12) also reveal in the X-ray diffraction pattern. Meanwhile, the artificial aged nanocomposite found decreased in hardness, compare to monolithic has higher value form early aged until 36 hours aging.

The main object of this study is to investigate the effect of friction stir processing (FSP) on the microstructure and hardness of Al-Zn-Mg-Cu alloys that were produced via casting with the addition of 5 wt % nickel. Furthermore, a single-pass FSP with a rotational speed of 1500 rpm and a traveling speed of 40 mm/min was performed on the alloys. The FSP-treated cast alloys were homogenized, aged at 120°C for 24 h, retrogressed at 180°C for 30 min, and then re-aged at 120°C for 24 h. Microstructural evaluations via optical microscopy and scanning electron microscopy, as well as with energy dispersive X-ray spectroscopy were conducted. In addition, X-ray diffraction analysis was performed to detect the intermetallics and phases of the Al-Zn-Mg-Cu-Ni alloys. Before FSP, the microstructural observations indicated the presence of coarse Ni dispersed particles with a precipitate phase within the matrix. After FSP treatment, the grain refinement led to the uniform space distribution of Ni dispersed particles in the stir zone. The Vickers hardness values for the Al-Zn-Mg-Cu-Ni alloy increased after age tempering at T6 and retrogression and re-aging (RRA) treatment because of the increased precipitation and particles dispersity. The hardness of the Al-Zn-Mg-Cu-Ni alloy was enhanced after FSP and a series of heat treatments, especially the RRA process, because of the stirring action of the FSP tool, the grain refinement, the appearance of additional precipitates, and the refinement of dispersed Ni particles.

This paper describes a study on the effects of heat treatment on the microstructure, hardness and wear of aluminum alloys 332 (AlSi9Cu3Mg). The solution treatment was performed at 500°C for 5 hours and then quenched in water at room temperature. Aging was performed at 170°C for 2 hours. The findings revealed that after a full heat treatment, the structure of the eutectic silicon formed toward fragmentation and spheroidization, and the silicon particles became coarse (look-like rounded). Hard intermetallic compound (Mg2Si) appeared on the microstructure after the aging treatment completed. Compared to the as-cast, the hardness of the alloys has improved to 44.84%, and the wear rate of the solution treatment had decreased to 26% while the aging treatment showed a deterioration of 79.42%. The study concludes that aging treatment improves the hardness of AA332 alloys and enhanced the wear resistance of the substance.

Cuprous oxide (Cu2O) thin films were formed onto indium tin oxide (ITO) coated glass substrate by sol-gel spin coating technique using different additives namely polyethylene glycol and ethylene glycol. It was found that the organic additives added had an important influenced on the formation mechanism of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet-visible spectroscopy (UV-Vis). Based on the FESEM micrographs the grain size of film prepared by polyethylene glycol has smallest grain of about 83 nm with irregular shape. The highest optical absorbance film was obtained by the addition of polyethylene glycol.

A Roselle blend chitosan film sensor (RBFS) with different concentration of roselle has been developed. Electrochemical deposition has been chosen as an efficient technique for the fabrication of RBFS. RBFS with the concentration of 20cc of roselle has a stable value to detect the different concentration of fertilizer ranging from 0 ppm until 60 ppm. The type of fertilizer used in this testing was magnesium sulphate. The electrical laboratory testing result of the RBFS exposed to de-ionised water (DIW) showed the highest response with the value ~94%. The highest response value of RBFS exposed to magnesium sulphate with the concentration of 10 ppm was ~66%. The lowest response value of RBFS exposed to magnesium sulphate with the concentration of 60 ppm was ~30%. The results have been proven that RBFS is able to differentiate the concentration of fertilizer. The RBFS fulfils all the reliable sensing properties which include excellent response time, stability, repeatability, recovery, and selectivity. The morphological surfaces of RBFS were observed with SEM and chemical interactions between roselle blend chitosan were explained using FTIR spectra results. SEM image of RBFS showed the film surface was compact and the roselle was well distributed within the chitosan.

In the present study, the effect of intermetallics phase had been investigated on microstructure and mechanical properties of Mg2Si(p)/AA332 composite. Each composites reinforced with 5, 10, 15 and 20 wt.% of Mg2Si particles developed by stir casting. The findings revealed that the microstructure of Mg2Si(p)/AA332 consist of α-Al, binary eutectic (Al+Mg2Si), Mg2Si particles and intermetallics compound. The intermetallics compound identified as β-Al5FeSi, θ-Al2Cu and Q-Al5Mg8Si6Cu2; formed as platelets (needle-like), polygonal and polyhedron respectively. The mechanical properties such as hardness increases over than 42% from as cast. The highest UTS, elongation and maximum quality index (Q.I.) achieved in sample of 10 wt.% Mg2Si. The study concludes that the amount of 10 wt% of Mg2Si shows an appropriate reinforcement quantity when reinforced in AA332.

Mechanical alloying was employed to synthesize Al–Zn–Mg–Cu alloys with nickel additives from elemental powders via high-energy ball milling. The milled powders were cold compacted and sintered thereafter. The sintered compacts underwent homogenization treatments at various temperature conditions and aged at 120 °C for 24 h (T6). Subsequently, the compacts were retrogressed at 180 °C for 30 min and re-aged at 120 °C for 24 h (RRA). The milled powders and heat-treated products were characterized via X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive spectroscopy. The crystallite sizes and micro-strains of the alloy powder were estimated with the broadening of XRD peaks by using the Williamson–Hall equation. The results show that Zn, Mg, and Cu atoms are soluble in the Al matrix after milling for 5 h. The Vickers hardness of Al alloys was enhanced following retrogression and re-aging treatments. The addition of nickel influenced the hardness of the compacted powders.

Electronic structure and magnetic properties of the three different samples of BiMn 2 O 5 , are calculated using the density functional theory (DFT). These samples have different Bi / Mn concentration. For simplicity, we suggest to call them as A, B and C. The calculated band structures show half metallicity for all samples, and possess 100% spin polarization at the Fermi level. The spin up/down density of states are calculated using Engel–Vosko generalized gradient approximation (EV-GGA). We have discussed the effect of Mn magnetic moment ( μ B ) on the electronic and magnetic properties of the entire samples. The temperature dependent thermoelectric properties like electrical and thermal conductivity, Seebeck coefficient and power factor are also calculated, employing the Boltzmann transport theory under the BoltzTraP code. Our results indicated that these properties are strongly dependent on Bi / Mn concentration.

High strength aluminum alloys Al-Zn-Mg-Cu-(0.1) Ni produced by semi-direct chill casting process were homogenized at different conditions then conducted heat treatment process which comprised pre-aging at 120°C for 24 h, retrogression at 180°C for 30 min, and then re-aging at 120°C for 24 h. Microstructural studies showed that add Ni (0.1 wt %) to the alloy will be forming Ni-rich phases such as AlCuNi, AlNi, AlNiFe and AlMgNi which provide a dispersive strengthening affected in the solid-solution and the subsequent heat treatments. The results showed that by this three-step process of heat treatments, the mechanical properties of aluminum alloys Al-Zn-Mg-Cu-(0.1) Ni were substantially improved. The highest attain for the ultimate tensile strength and Vickers hardness for the alloy sample after applied the retrogression and reaging process is about 545 MPa and 237 HV respectively.

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 grinding the iron mill scale to an effective particle size, which is 300μm. Latter, the grounded iron mill scale will undergo the magnetic separation process. The purpose of this process is to remove any non-magnetic material. Than the following process is to fully oxidize and reduce the iron mill scale to form pure iron powder. From this step an optimum value for maximum heating temperature, heating rate and heating cycle was determined. Than in order to determine whether the oxidation and the reduction process have completely achieved their objective, the iron oxide and the iron powder that have been produced from both process, was characterized using X-Ray Diffraction Analysis (XRD) and X-Ray Florescent Analysis (XRF) technique. From the oxidation process, it is obvious that sample C gave higher oxidation percentage, which is 11.22%. While Reduction 2 shows the desirable result, which is 29.51% of reduction, involving a low cost compared to other reduction process.

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 acidic electrolytes is made possible by the well known process parameters that have been studied over the years. These parameters i.e. voltage, current density, type of electrolyte etc have been very effective when anodizing aluminum at freezing temperatures. When the operating temperature is raised above the freezing temperature, additional process parameters would be required to make the pore formation possible. The fabrication of the aluminum foil was carried out using phosphoric acid as the electrolyte source. The electrolyte pH was adjusted to 1, 3 and 5 in order to simulate different anodizing conditions. A potential of 50 V from a dc power supply was applied across the electrochemical cell, while a power regulating device with different power rating was attached to the electrochemical cell to provide the operating system with additional parameters that could influence the surface structure of the alumina. The micrographs obtained show that the propagation and growth of the pores at both room and high temperatures was made possible by the power regulating device attached to the cell. Copyright © 2013 VBRI press.

In this study, the effect of anodizing voltage on the current density versus time transient, oxide mass and the current efficiency of anodizing of aluminium manganese alloy was reported. It was found that the anodizing voltage facilitated the pore nucleation process and increased the steady state current density. However, when the anodizing voltage is 70V, dielectric breakdown occurred. The current density versus time transient for anodizing conducted at 30 to 60 V were typical while the shape was unusual for anodizing conducted at 70 V. The rate of oxide growth increased as a function of anodizing voltage. The current efficiency of anodizing increased as the anodizing increased from 30V to 70V.

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 addition of 0.1, 0.3, and 0.5 g of polyethylene glycol (PEG). The addition of PEG to the TiO2 sol prevents surface cracks and improves the adhesion of the sol to the template to produce different surface morphologies which were visible under the scanning electron microscope (SEM). Although, complete degradation of the methyl orange (MO) dye was not achieved initially with the TiO2 coated template, until an oxidizer in the form of H2O2 with different concentrations of 0.029M, 0.088M, and 0.147M were added during the photocatalysis process to shorten the degradation time and to ensure complete mineralization of the MO dye.

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 conditions using the cyclic voltammetry tool. We investigate the reversibility of the electrochemical reaction as a redox reaction from the cyclic graphs that were obtained. We observed that the ratio of the peak current passed at both the reduction and oxidation when measured was very close to unity in all the pH but except one which produced a none reversible reaction with a non cyclic graph. The peak potential for both reduction and oxidation reactions using phosphate buffer saline as the analyte under different pH of 3, 5, 7, and 9 was also obtained.

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 tensile peel load were determined on the joint of welded specimens. The results showed that the value of tensile shear load was lower than tensile peel load. The strength of the joint increased with the increasing of welding current and welding cycle used in the welding process.

Composite approach in lead-free solder development was perceived as an expectation in finding new robust solder. Accordingly, Sn-0.7Cu/re-Al composite lead-free solder with varying amount of recycled-Aluminum (0, 3.0, 3.5 and 4.0 wt.% re-Al) particulates produced from aluminum beverage cans were successfully fabricated via powder metallurgy techniques in this study. This paper focuses on the thermal properties focusing on the melting temperature of the new developed Sn-0.7Cu/re-Al lead-free composite solder. The melting temperature (Tm) of the new solders was determined using differential scanning calorimetry (DSC). The melting temperature of the composite solders has showed comparable results with the monolithic solders of Sn-0.7Cu lead-free solder.

This paper presents a short review of research work on the development of synthesizing the colossal magnetoresistance materials through sol-gel method. Although there are a lot number of methods available, sol-gel method has been widely used and some excellent work has been reported. Two different manganite systems, which are LSMO and PSMO, that have been prepared through sol-gel method was choose for the discussion purpose. It was found that both systems were successfully prepared via the sol-gel method. Both systems showing better magnetoresistance properties compare to sample prepared through solid state reaction. X-ray diffraction technique was used to study the structural characteristic. Atomic force microscope and field emission scanning electron microscope were used in order to investigate surface morphology. Resistivity as a function of temperature was measured by a standard four-probe method.

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: E6013). The mechanical properties of welded joint were investigated by tension test. It was observed that, the yield strength and tensile strength of welded samples using mild steel welding electrode were slightly lower than welded samples using stainless steel welding electrode. All welded samples fractured at mild steel base metal indicated that the regions of stainless steel base metal, fusion zone and heat affected zone are stronger than mild steel base metal.

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 0.3 to 0.9 ppm in healthy people to more than 1.8 ppm for diabetics. This makes acetone a suitable chemical marker for diabetes diagnosis. Therefore, the preliminary study on the electrical laboratory testing of the chitosan film sensor properties to acetone vapor-contaminated air in range of 0.1–100 ppm was carried out at room temperature (∼25–30 °C) in normal air. Our results suggested that the proposed acetone-based gas sensor can operate at room temperature with a high performance demonstrated by good response, recovery, stability and repeatability. This trouble free, painless and steadfast technique will improve the current gold standard in diagnosing diabetes, enabling quick and early detection.

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 constructions. This study develop new products made of by biomass ash from industry waste for the internal partitions panel. Modifying the internal partition panel of wall with addition of biomass ash (EFB) and clay soils in producing new products that can resist and retain durability and resilience of the panel products to the fire. ASTM C1396 Standard Specification for Gypsum Board defines Gypsum wallboard as designed wallboard use for on walls, ceilings, or partitions and that affords a surface suitable to receive decoration tested in accordance with ASTM E1 19 Standard Test Methods for Fire Tests of Building Construction and Materials. For this study, fire resistance, thermal and mechanical parameters were measured. The panels which are 100 mm × 100 mm by 15 mm thick were prepared following ASTM standard. The product here studied in the form of low-density panels (800 kg/m) has a great potential for an industrial use, showing similar properties to those found in commercial gypsum plasterboard, a material of generalized use for this type of application. Consequently, from the test, biomass ash (EFB) panel board can retain more than 2 hours fire resistance in standard conditions of room temperature by fire laboratory and panels showing a compressive strength of 3.535 MPa.

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 383 Al alloys and hypereutectic 390 Al alloys. Various surface roughness averages (Ra) of different degrees were verified as well as three different loads 10, 20 and 30 N, speeds 200, 300 and 400 rpm and relative humidity 75%. Different analyzed through scanning electron microscopy and X-ray dispersive analyses. A pin on-disc apparatus was used for testing in lubrication sliding wear. It was noted that the weighted and volumetric wear rate decreases the degree of roughness and the friction coefficient is a function of the stability state. Wear rate is decreased and the transition from high to low wear increases with an increase in the average surface roughness. It was found that, after the sliding velocity, there was an increase in wear of Al-Si with increasing load, using a scanning electron microscope to study the wear mechanisms. At high speeds, The results of mechanical properties of aluminum silicon alloys were finally correlated with the amount of silicon in aluminum and secondary processing technique.

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 in this study was split into two steps. In the first step, the softness of Sn powder was exploited to modify the surface morphology of W particles. In the second step, Cu was added to the ball milled mixture. To achieve this goal, four 50 wt% W–bronze compact sets of different powder precursors and activator additions were produced. The sintering process was performed at 1150 °C. The two-step ball milled powder yielded sintered compacts of homogeneous microstructure of fine polygonal W grains dispersed in bronze matrix. They showed the highest hardness and densification levels. The sintered density, microstructure, hardness and densification mechanisms of the sintered compacts were investigated, examined and evaluated using different metallographic, microscopic and measurement facilities.

AZ91 nanocomposite was exposed to several heat treatment processes and the effect of precipitation hardening on hardness was studied as a function of time and temperature. The investigation shows the significant of time and temperature are the main role in the precipitation hardening process of the nanocomposite. Kinetics study show a deceptive activation energy of 21 kJ/mol of the AZ91 nanocomposite. A relationship was derived to predict the maximum hardness at given time and temperature.

Nanoporous alumina was produced by anodic oxidation of aluminum in both acidic and alkaline electrolytes. Previous reports indicate that nanoporous alumina is mainly produced from strongly acidic electrolytes, and with the use of a low freezing temperature controlled bath to control the propagation and growth of the pores. We design an in-house electrochemical cell with an electronic circuit box attached, to control the anodization of aluminum at room temperature. The electrolytes used were phosphoric acid solution and sodium hydroxide solution. The pH of the acidic electrolyte was adjusted to 1, 3 and 5 with an applied potential of 50V and anodization time of 1 and 3 hrs, respectively, while the alkaline electrolyte pH was adjusted to 9, 11 and 13 with an applied potential of 40V and the templates anodized for 5 hrs. The micrographs of the nanoporous alumina formed from these electrolytes confirm that the nucleation and growth of nanoporous alumina films is achievable with the aid of the electronic circuit box connected to the electrochemical cell. Copyright © 2012 VBRI Press.

Porous anodic alumina (PAA) has been produced on aluminium substrate by single-step anodising at 50 V in 0.3 M oxalic acid at 15°C for 60 min. The highly ordered pore and cell structure was achieved by subjecting the PAA to oxide dissolution treatment in a mixture of chromic and phosphoric acids. The nanostructure prior and post-oxide dissolution treatment was examined under scanning electron microscope. It was found that the oxide dissolution treatment improves the regularity of the cell and pore structure significantly. Uniform closely packed honeycomb structure of PAA is obtained. The uniformities of pore diameter and interpore distance are also enhanced. Compared to the PAA prior treatment, it was noticed that the pore diameter of the post-treatment PAA increases.

Leaching behaviour of Langkawi black sand was carried out in this study for the recovery of titanium. In order to determine the maximum leaching condition various parameters like effect of leaching time, temperature, concentration of sulfuric acid, solid to liquid ratio and volume of hydrogen peroxide were studied. The experimental data revels that the optimum temperature and time were 80 °C and 120 min, respectively. In addition, 5 M sulfuric acid, 2 mL of hydrogen peroxide and solid liquid ratio of 0.032 W/V showed the best leaching result.

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 as three different loads 10, 20 and 30 N, speeds 200, 300 and 400 rpm and relative humidity 77%. Different surface preparation techniques are resulted in different Ra values from (6, 8 and 12) ± 0.05 μm. The contacts were dried sliding and lubricated regime at 2.5 centimeters per second. Surfaces were analyzed with scanning electron microscopy and X-ray dispersive analyses. It was noted that the weighted and volumetric wear rate decreases as degree of roughness decreases, as well as coefficient of friction is considered as a function of the stability state. Wear rate is decreased and the transition stress from high to low wear is increased with increasing surface roughness average. There was a correlation between friction coefficient and hardness.

A nanocomposite solder alloy with 99.3Sn-0.7Cu base alloy was successfully fabricated using the powder metallurgy route which consists of blending, compaction and sintering. Varying amount of nano size silicon nitride particulates were introduced as reinforcements to obtain a novel lead-free nanocomposite solder alloy. Following fabrication, the sintered nanocomposite solder were cut into thin solder disc and were analyzed in terms of their wettability, electrical and mechanical properties. Wettability, electrical and mechanical properties of the nanocomposite solder were compared to 99.3Sn-0.7Cu and 96.3Sn-3.0Ag-0.5Cu lead-free solder which were fabricated with the same method using powder metallurgy route. Wettability property of the nanocomposite solder was found to be in the accepted range with wettability angle below 45° similar to 99.3Sn-0.7Cu and 96.3Sn-3.0Ag-0.5Cu lead-free solder. Besides wettability, the results of electrical and mechanical properties analysis showed that additions of nano size Si3N4 had enhanced the strength and electrical conductivity of nanocomposite solder comparing to 99.3Sn-0.7Cu and 96.3Sn-3.0Ag-0.5Cu lead-free solder.

With a sharp increase in demand and production, palm oil wastes, (i.e. empty fruit bunches, fibre and shells) are generated, out of which a large amount ends up in landfill. In such a context, alternative solutions are needed to reduce the impact of these agricultural wastes on the environment. The present paper investigates the effect of addition of agricultural waste materials on the combustion behavior of its blends with metallurgical coke (MC). Two types of agricultural waste materials, palm shell and coconut shell, were mixed in different proportion with MC, while the gas phase reactions were studied at 1200°C in a drop tube furnace (DTF). In the tested conditions, the blends containing agricultural waste materials indicated higher combustion efficiencies compared to MC alone. Carbon structure analysis were performed through 13CP/MAS NMR spectroscopy showing various groups of carbons present in the agricultural waste samples ranging from aliphatic to aromatic carbons. The morphology of the samples was studied through Scanning Electron Microscope (SEM). SEM provided a qualitative description of the pore structure in the raw samples as well as the changes occurring following the gas phase reactions in the DTF. It was found that the particles derived from the wastes became increasingly deformed and lost their cell lumen. Surface area measurements were found to be in good agreement with the SEM images, supporting the higher combustion efficiency of the blends in comparison to coke alone. The present study suggests that agricultural waste materials have the potential to partially replace MC, as an auxiliary fuel in metallurgical processes.

The influence of heat treatment on the corrosion behavior of two aluminium matrix composites (AA2014/15 vol% Al2O3p composite A and AA2009/20 vol% SiCw composite B) was analyzed in 3.5% sodium chloride solution. The kinetic of the corrosion process was studied based on the gravimetric measurements. The corrosion damage and pit shape were analyzed by Image Analyzer. The corrosion damage in both composites was caused by the pitting attack on the surface. Pit shape of the composite A is different to the composite B. The corrosion rate of composite A is higher than composite B because the voids or gap between reinforcement particles and matrix are larger than in the composite B. The main attack of nucleation sites was at the interface region of the matrix and the reinforcement.

In this paper, the effects of nickel on the microstructure and mechanical properties of experimental an Al-Zn-Mg-Cu PM alloys under the impacts of the retrogression and re-aging treatment was investigated. Green compacts pressed at 370 MPa were then sintered at temperature 650°C in argon atmosphere for two hours. The sintered samples subjected to the homogenizing condition at 470°C for 1.5 hours then aging at 120°C for 24 hours and retrogressed at 180°C for 30 minutes, and then re-aged at 120°C for 24 hours. Characterization’s results indicate that the microstructures of an Al-Zn-Mg-Cu-Ni PM alloys presented an intermetallics compound in the aluminum’s matrix, identified as the AlNi and Al3Ni2 phases besides the MgZn and Mg2Zn11 phases which produced of the precipitation hardening during heat treatment. These compounds with precipitates provided strengthening of dispersion that led to improved Vickers’s hardness and dinsifications properties of the alloys.