عنوان مقاله [English]
The effect of beryllium addition (200 ppm and 2000 ppm) on dynamically formed double oxide film of aluminum A356 alloy was investigated. Dynamically double oxide films were obtained by gravity casting in a cup of thin-walled steel at different free fall of melt and solidified under a vacuum of 80 mbar. The melt quality according to the bifilm index for melts containing 2000 ppm of beryllium for molten free fall height of 200 and 300 mm is 5.6 and 5.20 mm, respectively. Scanning electron microscopy (SEM) images show a change in the morphology and thickness of the young double oxides containing the beryllium element in dynamic conditions. By adding 2000 ppm of beryllium, the thickness of the film is reduced. For amount of 200 ppm, the edges of the oxide screed and its greater thickness are oxide film properties. Reducing the thickness can mean increased flexibility of oxide films composed of melt containing beryllium. Also, the radiographic results of RPT samples showed that the cavities were reduced by adding beryllium.
 Hinton E.M., The oxidation of liquid aluminium and the potential for oxides in grain refinement of aluminium alloys, Thesis: University of Birmingham, August, 2014.
 Dispinar D., Campbell J., Critical assessment of reduced pressure test. part 2: Quantification, Cast Metals Research, 2004, 17(5) 287-294,.
 Zeng X., Wang Q., Lu Y., Ding W., Zhu Y., Zhai C., Lu C., Xu X., Behavior of surface oxidation on molten Mg–9Al–0.5Zn–0.3Be alloy, Materials Science and Engineering A, 2001, 301, 154-161.
 Fox S., Campbell J., Visualisation of oxide film defects during solidification of aluminium alloys, Scripta Materialia, 2000, 43, 881-886,.
 Glazoff M.V., Rashkeev S.N., Beryllium adsorption at transition aluminas: implications for environmental science and oxidation of aluminum alloys, J. Phys. Chem. C, 2010, 114, 14208–14212.
 Asadian-Nozari M., Taghiabadi R., Karimzadeh M., Ghoncheh M.H., Investigation on beneficial effects of beryllium on entrained oxide films, mechanical properties and casting reliability of Fe-rich Al–Si cast alloy, Materials Science and Technology, 2015, 31(4) 506-512.
 Lee J. K., Byun J. S., Kim M.H., Effects of beryllium on the Characteristics of Oxide Film in the Al-Si-Mg Alloy, Kor. Inst. Met. & Mater, 2000, 38(1) 219-225.
 in Metals Handbook, Tenth ed, ASM International Handbook Committee, 1990, 1238.
 Bergsmark E., Simensen C.J., Kofstad C., Oxidation of molten aluminum, Mat. Sci. Eng. A, 1989, 120, 91-95.
 Agema K.S., Fray D.J., Preliminary investigation on the deformation behaviour of an oxide scale on molten aluminium, Department of Material Science and Metallurgy, University of Cambridge, 1989.
 Drouzy M., Mascré C., The oxidation of liquid non-ferrous metals in air or oxygen, Metall. Rev,1969, 14, 25-46.
 Kahl W., Fromm E., Examination of the strength of oxide skins on aluminum alloy melts, Metallurgical Transactions B, 1985, 16(1) 47-51.
 Divandari M., Campbell J., Morphology of oxide films of Al–5Mg alloy, Cast Metals Research, 2005, 18, 187-192.
 Blackburn P.E. and Gulbransen E.A., Aluminum reactions with water vapor, dry oxygen, moist oxygen, and moist hydrogen between 500° and 625°C, Electrochem. Soc, 1960, 107, 944-950.
 Syvertsen M., Oxide skin strength on molten AA5XXX aluminum alloy—effect of beryllium and alternatives, The Minerals, Metals & Materials Society, 2017, 1451-1455.
 Wikle K.G., Improving aluminum castings with beryllium, in AFS Transactions, Pennsylvania, April, 1978.
 Zeng X. Q., Wang Q. D., Lu Y. Z., Ding W. J., Lu C., Zhu Y. P., Zhai C.Q., Xu X. P., Kinetic study on the surface oxidation of the molten Mg-9Al-0.5Zn-0.3Be alloy, Materials Science, 2001, 36, 2499-2504.
 Divandari M., Campbell J., Oxide film characteristics of Al–7Si–Mg alloy, Cast Met Res, 2004, 17, 182-186.
 Bartar-Esfahani H., Raiszadeh R., Doost-mohammadi H., The effect of strontium on the strength of layers of double oxide film defects, Metall and Mater Trans A, 2016, 47A, 1331-1338.