APPROACH TO THE FERROMAGNETIC SATURATION OF THE FE39CO33Y8B20 ALLOY PRODUCED USING TWO METHODS |
Author : Marcin NABIALEK, Kinga JEZ* |
Abstract | Full Text |
Abstract :The article presents results of investigations of the structure and selected magnetic properties of a bulk amorphous alloy with the chemical composition Fe39Co33Y8B20. Alloy was produced using two methods: injection suction liquid alloy into a water-cooled copper mold. Structure of the materials was examined using X-ray diffraction. Magnetic properties were determined on the basis of measurements by the vibration magnetometer and the Faraday magnetic weight. Alloy samples produced were characterized by high Curie temperature (over 700 K) and soft magnetic properties, i.e. high saturation magnetization (1.1 T) and low coercive field value (below 200 A/m). On the basis of the primary magnetisation curves, the type of defects occurring in the samples of manufactured alloys was determined and the spin wave stiffness parameter was determined. |
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FTIR-SPECTROSCOPY STUDY OF MICROWAVE AND CONVENTIONAL HEATING ON THE DEGRADATION OF MARGARINE AND BUTTER |
Author : Fatos REXHEPI1,*, Gresa KURTI1 , Flora FERATI1 , Shkumbin SHALA2 |
Abstract | Full Text |
Abstract :Our investigation consists to evaluate the effects that microwave heating (5 min at 1100 W) and conventional heating (18 min at 180 °C and 20 min at 250 °C) have on margarine and butter samples. The finally experimental results showed oxidations of margarine and butter samples during conventional heating which is in contrast with microwave heating for both treated samples used ratio of characteristic FTIR absorbances used as indicator of oxidation level. Significant increases in intensity of FTIR vibrations which corresponding with imine group in region from 1690-1640 cm–1 were compared after conventional oven heating, showing that there do not have any increase intensity in this region of spectra. Otherwise, microwave heating different impact has on evaporation of polar ingredients such as water in margarine samples compare with several butter which contain low level of water but evaporation is happened easy which is coming from different type of interaction of between microwave and water and this type of energy can’t be transfer all in water molecule and to initiate evaporation. Therefore, the degradation of margarine and butter samples can be accurately measured using FTIR spectroscopy as a green, sensitive and not expensive method of analysis. |
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PREPARATION AND CHARACTERIZATION OF METAL ORGANIC CHEMICAL VAPOUR DEPOSITED COPPER ZINC SULPHIDE THIN FILMS USING SINGLE SOLID SOURCE PRECURSORS |
Author : Joseph Onyeka EMEGHA1,*, John DAMISA1 , Frank Ochuko-oghene EFE2 , Bolutife OLOFINJANA2 , Marcus Adebola ELERUJA2 , Sam Ogochukwu AZI |
Abstract | Full Text |
Abstract :Metal organic chemical vapour deposition (MOCVD) was used with a mixed single solid source precursors of copper dithiocarbamate (CuC10H16N2O2S4) and zinc dithiocarbamate (ZnC10H16N2O2S4) to prepare pyrolysed copper zinc sulphide thin films. The precursors were analysed by Fourier Transform Infrared Spectroscopy (FTIR), to determine the structures present. The films were deposited on glass substrates at a temperature of 420 0C. Experimental results showed that the compositional studies were found to be complementary. The structural analyses revealed that the film is crystalline with an average grain size of approximately 4 µm. An optical band gap energy of 2.50 eV was obtained with an absorbance that decreases with wavelength. The electrical characterization gave values of sheet resistance, resistivity and conductivity of the film as 5.13 x10-6 ?/Sq, 2.27 x 10-1 ?.cm and 3.61 x 10-2 (?.cm)-1 respectively. The findings confirmed that the synthesized precursors are potential materials for depositing high quality copper zinc sulphide thin films. |
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FATIGUE AND TENSILE FRACTURE SURFACE MORPHOLOGIES OF ADDITIVE MANUFACTURED AUSTENITIC STAINLESS STEEL |
Author : Penn RAWN, Vadiraja SUDHAKAR |
Abstract | Full Text |
Abstract :Fatigue and tensile fracture surface morphologies of laser additive manufactured (LAM) stainless steel (using powder bed fusion method) were investigated. Both fatigue and tensile fracture surface morphologies were determined using LEO-VP SEM instrument. The fracture surface features were studied as a function of global energy density, one of the main LPBF processing parameters used in producing 316L SS test specimens. The fracture surface morphologies were also compared with the wrought 316L SS fractured specimens. It has been demonstrated that relatively higher energy density (irrespective of the specimen build angle orientations) specimens resulted in predominantly ductile fracture, while lower energy produced relatively brittle fracture surface characteristics, in tensile fractured specimens. Among fatigue fractured specimens, LPBF processed specimens at 90º build angle demonstrated relatively higher ductile fracture characteristics. |
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EFFECT ON MICROSTRUCTURAL AND PHYSICAL PROPERTIES OF Sn-3.0Ag-0.5Cu LEAD-FREE SOLDER WITH THE ADDITION OF SiC PARTICLES |
Author : Zawawi MAHIM, Mohd Arif Anuar MOHD SALLEH* , Norainiza SAUD |
Abstract | Full Text |
Abstract :The Lead-free solder has been subject of concentrated research activity over the past era, but it is hard to meet the characterization and mechanical properties of Sn-Pb solder. Sn-Ag-Cu and Sn-Cu family of alloys were the most ideal and capable among all the Pb-free solder alloys proposed. Much publicity had been received by the eutectic Sn-3.0Ag-0.5Cu and Sn0.7Cu solidifying their position as the most promising successor to Pb alloys solder. This study was to carry through the investigation of the effect of SiC particle on microstructure development and physical properties of Sn-3.0Ag-0.5Cu (SAC) based solder alloys. Powder metalurgy method (PM) was used to synthesize SAC-SiC composite solders, which involves some processes like mechanical blending, compaction and sintering. The outcome shows the additional of SiC particle has decreasing the ß-Sn region and at the same time, the values of microhardness were increased. |
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STRUCTURAL ANALYSIS OF Ti-Mo ALLOYS |
Author : Iustinian BALTATU1 , Petrica VIZUREANU1,2,* , Madalina Simona BALTATU1 , Drago? ACHITEI1 , Marcin NABIALEK3 |
Abstract | Full Text |
Abstract :In the last decade, many researchers have demonstrated that Ti-based alloys for implants, with different biocompatible elements (Zr, Ta, Mo, Si, Nb etc.) have positive responses interaction with bone tissues, promoting an adequate osseointegration. An ideal biomaterial, possesses an ideal combination of microstructure, mechanical properties and corrosion resistance. Ti-Mo are promising biomaterials candidates because presents specific advantages (mechanical properties, biocompatibility, corrosion resistance etc.) without affecting the health of the patient. In the current investigation is presented the correlation of ß Ti alloys effect on the microstructure and micro-hardness properties. The samples were produced by argon arc-melting method. In connection with the researches reported in the field of biomaterials, Ti-Mo group are good candidates to orthopedic applications, thus aiming to replacing existing ones. |
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