Current Issue : July - September Volume : 2020 Issue Number : 3 Articles : 5 Articles
Ternary Al-4.5 (wt%) Cu-3.4 (wt%) Fe in-situ composite was prepared at\n1100DegreeC by conventional casting method. However, this particular alloy contains\nlarger needle-shaped intermetallics of Al3Fe phase. These exert adverse\neffect on the mechanical properties of the alloys. The larger shape and uneven\norientation of the intermetallic were found to be responsible for the degradation\nof properties. The main purpose of this study was to modify the geometry\nof those needles by adding magnesium (Mg) as a fourth material. A series\nof alloys were prepared by adding 4, 6, 8, 10, wt% Mg in Al-4.5 (wt%) Cu-3.4\n(wt%) Fe alloy. Microstructures were observed by optical microscopy. Mechanical\nproperties like ultimate tensile strength, % elongation, % area reduction,\nhardness and wear test were determined. The study revealed that Mg\ntransformed the needles of Al3Fe into globular shape which gave the alloys\nbetter mechanical properties....
By means of TEM, hardness, conductivity, tensile strength test, fracture\ntoughness test, polarization curve and EIS, the Al-Zn-Mg-Cu alloys treated by\na new multi-stage aging system,...................
Natural fibers have become essential elements to produce composites, which\nhave the renewability, sustainability, low cost and less health hazardous. Natural\nwastes improved the physical and mechanical properties of polyester-\nbased composites. Reinforced polyester composites with natural fibers are\nspread widely in recent decades as an alternative to synthetics. This paper\ndeals with effectiveness of palm fronds when they were added to a polyester.\nPercentage of palm fibers with respect to polyester is considered through present\nwork. A Pin-on-disc tribometer has been used in experimental work under external\nforces, and the correlations of coefficient of friction have been used to\nmake analysis of the experimental results. Ibertest universal testing machine was\nused to measure the tensile strength at a crosshead speed of 8 mm/min. The experimental\nanalysis shows the improvement of properties of the used reinforced\npolyester, where, the results show that the highest values of coefficient of friction\nare 1.16667 for 5 N load and the lowest value is 0.55 for 9 N load. And the\nchange for load 11 N is not significant. And also, 7.01 MPa is the highest value\nfor tensile strength with the lowest value of modulus of rigidity 5.84 when the\npalm frond content is 3% and the lowest value of tensile test is 4.81 MPa with\nthe highest value of modulus of rigidity 11.9 when 21% content....
Because Silicon carbide (SiC) ceramics have various excellent properties, the\ndemand for larger and complicated shapes has been increasing. This paper\nintroduces an innovative method that would not require a large furnace, and\nfurther, would minimize the production cost and the thermal history, namely\nthe â??flash-bondingâ? technique. The borosilicate glass with low thermal expansion\ncoefficient, Pyrex glass, was selected as the brazing material. In this\nwork, as-is or surface-oxidized SiC plates were joined using Pyrex glass as\nbrazing material, and the reaction and wetting of Pyrex glass on as-is or surface-\noxidized SiC plate were investigated. It was found that the protective film\nof the surface-oxidized SiC lowered the oxygen partial pressure, and hence,\ngenerated many pores in the interface....
Technetium-99 is a radioactive isotope with a half-life of 2.13 Ã? 105 year. 99Tc\nis a significant contaminant of concern to the world. For this reason, a detailed\nunderstanding of technetium chemistry is essential for the protecting\nthe public and the environment especially after increasing the various applications\nand uses of isotopes in the medical practices. Therefore, treatment of\nwaste increases prior to the safe discharge to the environment or the storage.\nThe sorption of technetium in the form of pertechnetate on a nano manganese\noxide loaded into activated carbon has been investigated. Nano manganese\noxide (NMO) was synthesized from manganese chloride and potassium\npermanganate by co-precipitation and forming a new composite by loading a\nnanoparticle into a modified activated carbon by different ratios. Modifications\nof activated carbons using different concentrations of HNO3 (4 M, 6 M\nand 8 M) are used in prepared composites. Fourier transform infrared spectroscopy\n(FT-IR), X-Ray Diffraction (XRD) and Scanning Electron Microscope\n(SEM) were used to characterize the prepared composites...........................
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