Abstract: In this experimental work, the viscosity of copper powder mixed with developed binder system based on palm stearin were studied and analyzed by means of rheological test. The feedstock is limited to 65 vol% of copper powder and 35 vol% of binder system; each of which consists of palm stearin (PS) and polyethylene (PE) prepared in four distinct formulations; 50 wt.% PS, 60 wt.% PS, 70 wt.% PS and 80 wt.% PS. Both copper powder and binder system were initially mixed to produce four sets of homogeneous feedstock. The rheological characterizations of the feedstock which includes its viscosity, pseudo-plasticity, shear sensitivity index (n), and yield stress were analyzed by using Rosand RH2000 Capillary Rheometer at a temperature of 150°C. Finally, the moulded parts were immersed in the n-heptane solution for 7 hours. The morphology analysis by Scanning Electron Microscope (SEM) by means of Hitachi SU 3500 Scanning Electron Microscope were carried out at the end of every stage. The study has shown clearly that PS plays several important roles in the composite binder system.
Abstract: Iron foam is a type of material having potential to be used as water or air filter andimplant material. One of the limitations of this material is its high reactivity on corrosion. In thepresent research TiO2 coating on iron foam substrate has been developed by self-assembledmonolayer method. Focus is given on the effect of TiCl4 and chitosan concentration on thecharacteristic of the developed TiO2 layer. Precursor was prepared with HCl concentration of 0.5; 1;1.5 M and chitosan solution concentration of 1% ; 2% ; 4% (w/v). Scanning Electron Microscopy(SEM) and Energy Dispersive Spectroscopy (EDS) characterizations show that TiO2 particles areformed on the iron foam surfaces. It was observed that with the higher TiCl4 concentration moreTiO2 particles obtained on substrate surfaces. On the other hand, SEM results also show the averageTiO2 particles size at around 1 micrometer and in tetragonal shape. It was observed that with thehigher chitosan concentration, the particles shape tend to have tetragonal stucture, while at lowerchitosan concentration (1%), agglomeration of TiO2 particles were observed.
Abstract: This paper investigates the mechanical properties of drilled and non-drilled glass fiber reinforced polymer (GFRP) composites of plain woven and stitch bi-axial ±45° fabrics. Vacuum-assisted resin transfer moulding was employed to fabricate the composite panels. In the first stage of this study, mechanical properties such as tensile strength, flexural strength, and volume fraction of the composites were determined by per ASTM standards. Later on, the fabricated GFRP composites were drilled in order to investigate the delamination damage. Based on this issue, residual strength was evaluated after drilling process using constant feed rate and spindle speed but different drill bit geometries, which include twist drill bit and step drill bit. Experimental results showed that plain woven performed better in term of mechanical properties and residual strength after drilling process. In addition, residual strengths of drilled composites using step drill bit exhibited superior performance than that of the twist drill.
Abstract: Statistical quality improvement techniques such as design of experiments (DOE) and Taguchi methods form an essential part of the search for improved product performance. This paper applies both the Taguchi and full factorial design techniques to highlight the application and to compare the effectiveness of the Taguchi and full factorial design processes as applied on surface roughness. Besides that, to determine the optimal parameter setting for each factor in surface roughness. For this study, we used two different probes of Mahr Surf XR20 which was MFW 250 tracing arm 6851804 (25μm) and tracing arm 6851806 (50μm). The main effect and interaction plot had been analyzed by using MINITAB (software). The experiment result showed that full factorial design performs better than Taguchi method.
Abstract: -Fe-Cr phase was investigated using formula Fe80Cr20. Ball milling process and ultrasonic technique is successfully done to develop solid solubility and improve homogenous, respectively. However, the effect of the Cr to Fe powder is not complete investigated using combination of its process. Ball milling is conducted by milling time of 60 hours and ultrasonic technique were carried out at ultrasonic time of 3 h, 3.5 h, 4 h, 4.5 h and 5 h. From the strain effect analysis is obtained that the strain increased with crystallite size decreased and broad peaks due to the micro strain that is obtained from the increasing d-spacing. The solid solubility and lattice parameter of the material relatively increased from the untreated sample to treated samples with the highest solid solubility of 62.1% and highest lattice parameter of 3.091 nm which is located at the milled and UB 4.5 hours. It is caused the temperature increased that effect to the higher diffusion of the atom. Therefore, the combination treatment is highest promote to improve the properties of the metallic materials.
Abstract: The increase of environmental issues awareness has accelerated the utilization of renewable resources like plant fiber to be used as reinforced material in polymer composite. However, there are significant problems of compatibility between the fiber and the matrix due to weakness in the interfacial adhesion of the natural fiber with the synthetic matrices. One of the solutions to overcome this problem is using chemical modification like alkali treatment. In this study, the impact of alkali treatment conditions on short randomly oriented kenaf fiber reinforced polyester matrix composite tensile strength was investigated. The experimental design setting was based on 2 level factorial experiments. Two parameters were selected during alkali treatment process which are kenaf fiber immersion duration (at 30 minute and 480 minute) and alkali solution temperature (at 40°C and 80°C). Alkali concentration was fixed at 2% (w/v) and the kenaf polyester volume fraction ratio was 10:90. The composite specimens were tested to determine the tensile properties according to ASTM D638-10 Type I. JOEL scanning electron microscopy (SEM) was used to study the microstructure of the material. The result showed that alkali treatment conditions setting do have the impact on tensile strength of short randomly oriented kenaf polyester composite. The interaction factors between immersion time and temperature was found to have prominent factors to the tensile strength of composite followed by the immersion time factor.
Abstract: Barium hexaferrite is categorized as hexagonal ferrite material with ferrimagnet properties. Barium hexaferrite has high coercivity, curie temperature, anisotropy magnetic field, and chemical stability that is often used as permanent magnet. It can be synthesized by using bottom up or top down method. The bottom up method of sol-gel has potential advantages in industry application compared to the top down method because of low energy requirement, more homogeneous product, and low time consuming to achieve nanometer size. The development of sol-gel method by using tapioca and chitosan as surfactant increases the quality of the product. Tapioca is used to increase anisotropy properties of particles by changing the particles shape into rodlike shape whereas chitosan is used to stabilize them at small size. Molar ratio of Fe3+/Ba2+ is set on 12 and the ratio of tapioca/chitosan is set on 1/3, 1/2, and 1. Iron (III) nitrate is used as Fe3+ source whereas barium nitrate is used as Ba2+ source. Condensation is done by heating up the sol system in the oven at 100OC. The product then is calcined at 1000OC with holding time of 3 hours. The calcined product is then characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Vibrating Sample Magnetometer (VSM). XRD result shows that the hematite phase has still been formed. The occurrence of the phase indicates that the reaction between iron and barium is uncompleted. SEM images show the existence of needle and rod-shaped particles with diameter of 200nm–550nm. It explains that tapioca can be used as rodlike template. The increase of tapioca tends to enlarge the rod-shaped particle and remove the needle-shaped particle. VSM result shows that the highest value of Br is found in the sample of tapioca/chitosan with the ratio of 1/3 and the value of 24 emu/g. The fact indicates that the optimal ratio of tapioca/chitosan is 1/3.
Abstract: Waste cooking oil has always been an environment problem in food factories and one method of effect disposing this oil without effecting the environment is to convert it to fatty acid methyl ester (FAME) using small scale pilot plant. The conversion of waste cooking oil with sodium hydroxide as a catalyst in conversional process at 22kHz speed. The reaction of time, molar ratio, speed, catalyst and amount of catalyst will be effect in FAME quality. The quality of biodiesel define is total ester content using gas chromatography. Gas chromatography analysis is a one of technique for identification and quantitation of compounds in a biodiesel sample. From biodiesel sample can identification of contaminants and fatty acid methyl ester. In this research biodiesel sample were analyses using a gas chromatography-flame ionization detector ( Perkin Elmer GC Model Clarus 500) equipped with a DB-5 HT capillary column ( 0.53mm x 5 m) J&W Scientific. The analytic conditions for ester content were as follow by: column temperature used 2100C, temperature flame ionization detector (FID) of 2500C, pressure of 80kPa, flow carrier gas of 1ml/min, temperature injector of 2500C, split flow rate of 50ml/min, time for analysis 20 minute and volume injected of 1 μl. The ester content (C), expresses as a mass fraction in present using formula (EN 14103, 2003a) calculation. Conversion of triglyceride (TG) to FAME using conversional process obtained 96.54 % w.t with methanol to oil molar ratio 6:1, 1%w.t acid sulphuric and 1% w.t sodium hydroxide catalyst.
Abstract: The application of molasses as a binder in sand mold operation was investigated. Standard Sand Mold mixture (5 cm diameter x 5 cm height) were made with 1-5% molasses and Chalawa sand the balance. The molding Properties such as ; Green Compressive Strength(GCS), Green Shear Strength(GSS), Dry Compressive Strength(DCS), Dry Shear Strength(DSS), Green Shatter Index, Green Permeability, Flowability, and Compactibility of sand molasses mixture were obtained. 2% Molasses-sand mixture was selected for molding the prototype cast based on the highest values of the Green Compressive Strength, Green Permeability, and excellent Flowability (96.4%) observed in the experiments. The result shows that molasses alone could not be used as a binder. This is further supported by the low values of Green Shatter Index (31.3%) and Compactibility (25%) reported.
Abstract: The effects on the properties of recycled latex glove (RL-G) filled Epoxidized Natural Rubber (ENR 50) were studied. Both compounds were prepared by two roll mill at five different compositions of RL-G (5, 15, 25, 35 and 50 phr). The size range of RL-G particles i.e., S1 (300μm-700μm) and S2 (3cm-5cm) were used. The properties such as tensile properties (tensile strength, elongation at break, and stress at 100% elongation) and morphology studies were determined. The results indicated that the both size, S1 and S2 of recycled latex glove filled ENR 50 blends exhibited an increased in tensile strength and elongation at break for increasing weight ratio of RL-G. Scanning electron microscopy (SEM) of the fracture surfaces shows that the fine size, S1 RL-G/ENR50 exhibited high surface roughness and matrix tearing lines than the coarse size, S2 thus improving the compatibility of RL-G/ENR50 compounds. The results overall indicated that the fine size, S1of RL-G filled ENR50 contributed to the better properties such as tensile strength and surface morphology compared to the coarse size, S2 mainly at 15 phr of RL-G content.