In this research the effect of cooling rate and mold type on mechanical properties of the eutectic
and hypoeutectic (Al-Si) alloys has been studied. The alloys used in this research work were (Al- 12.6%Si
alloy) and (Al- 7%Si alloy).The two alloys have been melted and poured in two types of molds with
different cooling rates. One of them was a sand mold and the other was metal mold. Mechanical tests
(hardness, tensile test and impact test) were carried out on the specimens. Also the metallographic
examination was performed.
It has been found that the values of hardness for the alloys(Al-12.6%Si and Al-7%Si) which poured in
metal mold is greater than the values of hardness for the same alloy when it poured in a heated metal
mold at different temperatures or in sand mold. The strength and impact resistance for the alloys (Al-
12.6%Si and Al-7%Si) are greater when these were poured in a metal molds than that when it poured in a
sand mold.
Furthermore, the higher cooling rates enhance the strength, hardness and impact resistance for the
two alloys, while the low cooling rates reduces these mechanical properties.
The percentage of elongation and the amounts of formed porosity decreased when the cooling rates
increased
Plastic soil exhibits unfavorited geotechnical properties (when saturation), which causes negative defects to engineering structures. Different attempts (included various materials) were conducted to proffer solutions to such defects by experimenting in practical ways. On one hand, these attempts aimed to improve the engineering characteristics of plastic soil, and on the other hand, to use problematic waste materials as a stabilizer, like cement kiln dust, and to reduce environmental hazards. This paper explored the shrinkage, plasticity, and strength behavior of plastic soil enhanced with cement dust. The cement dust contents were 0%, 5%, 10%, 15% and 20% by dry weight of soil. An experimental series of shrinkage and p
... Show MoreSulphated zirconia (SZ) is one of the most important solid acid catalysts was synthesize at different operating conditions, different calcination temperature and sulfonating time has been used. The prepared catalyst was distinguished by X-ray Diffraction (XRD), particle size and morphology of catalyst were checked by atomic force microscopy (AFM) and scanning electron microscopy (SEM) respectively, in addition to analysis by (DTA) Differential thermally and Energy Dispersive X-Ray (EDX). Finally, the N2 adsorption-desorption was used to measure the surface area (BET) and pore volume. High degree of tetragonal crystallinity was obtained 90 %, and surface area of 169 m2/g and pore volume of 0.39 cm3g-1 at 600°C calcination temperature for 3
... Show MoreThe deposition process and investigation of the physical properties of tungsten trioxide (WO3) thin films before and after gamma irradiation are presented in this paper. The WO3 thin films were deposited, using the pulse laser deposition technique, on glass substrates at laser energies of 600mJ and 800mJ. After deposition, the samples were gamma irradiated with Co60. The structural and optical properties of polycrystalline WO3 thin films are presented and discussed before and after 5kGy gamma irradiation at the two laser energies. X-ray diffraction spectra revealed that all the films consisted of WO3 crystallized in the triclinic form; the dislocation density and lattice strain increased with the absorbed dosage of gamma
... Show MoreThin films of In2O3-CdO at various CdO contents (0.01, 0.02, 0.03, 0.04 and 0.05) were deposited on transparent substrate which is glass using chemical spray pyrolysis deposition method at substrate temperature 150oC. The structural properties was studied to characterize the prepared materials by XRD analysis. Surface morphology has been illustrated using scanning electron microscopy which proved the nanosize of prepared materials. This materials have been used as gas sensor for toxic gas which is hydrogen sulfide H2S. The sensitivity and response speed have been investigated with addition of CdO nanoparticles. © 2021, S.C. Virtual Company of Phisics S.R.L. All rights reserved.
The petrophysical characteristics of five wells drilled into the Sa'di Formation in the Halfaya oil field were evaluated using IP software to determine a reservoir and explore hydrocarbon reserve zones. The lithology was evaluated using the M-N cross-plot method. The diagram showed that the Sa'di Formation was mainly composed of calcite (represented by the limestone region) is the main mineral in the Sa′di Reservoir. Using a density-neutron cross plot to identify the lithology showed that the formation mainly consists of limestone with minor shale. Gamma-ray logs were employed to calculate the shale quantity in each well. The porosity at weak hole intervals was calculated using a sonic log and neutron-density log at the reservoir
... Show MoreDifferent additives are used in drilling fluids when the demanded properties cannot be gotten with clays. Drilling muds needs several additives and materials to give good characteristics. There are local alternatives more suitable for enhancing the rheology and filtration of drilling fluids. An experimental work had been conducted to assess the suitability of using potato starch to enhance rheological properties and filtration in drilling mud. This study investigated the potato starch as a viscosifier and fluid losses agent in drilling fluid. Results from this study proved that rheological properties of potato starch mud increased when pH of drilling fluid is increased. Potato starch could be used to enhance gel strength at low pH
... Show MoreSuggested in this study the introduction of monomers have the ability to interact with polyester Rzn way confused or Alchapak Vodev polycarbonate first Almiaal acrylate ????? grains and offered models for high temperature and for a period of time of 40 days and absorbance and penetration and after color changes resulting from the storage heat higher using shades where models were extractedthermal storage and take measurements and then returned periodically results were consistent with theoretical expectations and mixing
The effect of Al dust particles on glow discharge regions, discharge
voltage, discharge current, plasma potential, floating potential,
electron density and electron temperature in planar magnetron
sputtering device has been studied experimentally. Four cylindrical
Langmuir probes were employed to measure plasma parameters at
different point on the radial axis of plasma column. The results
shows the present of Al dust causes to increase the discharge voltage
and reduce the discharge current. There are two electron groups in
the present and absent of Al dust particles. The radial profiles of
plasma parameters in the present of dust are non- uniform. The
floating potential of probe becomes more negatively while
Polymer blended electrolytes of various concentrations of undoped PAN/PMMA (80/20, 75/25, 70/30, 65/35 and 60/40 wt%) and doped with lithium salts (LiCl, Li2SO4H2O, LiNO3, Li2CO3) at 20% wt have been prepared by the solution casting method using dimethylformamide as a solvent. The electrical conductivity has been carried out using an LCR meter. The results showed that the highest ionic conductivity was 2.80x10-7 (Ω.cm)-1 and 1.05x10-1 (Ω.cm)-1 at 100 kHz frequency at room temperature for undoped (60% PAN + 40% PMMA) and (80% PAN + 20% PMMA) doped with 20%wt Li2CO3 composite blends, respect
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