The effect of applying vibration to a melt on the behaviour of bifilm defects in A356 and A357 melts was studied using a reduced pressure test technique. The results showed that vibrating a melt can have a dual effect on bifilms. This effect depends on the rate of phase transformations that occur in the oxide films. If the transformation occurs fast enough then the vibration would facilitate the formation of bonding between the layers of bifilm defects by causing the atmosphere of the defects to be consumed faster. Otherwise, the vibration might facilitate the diffusion of hydrogen into the atmosphere of the defects, and hence prevent or delay the formation of bonding between the oxide layers.
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AhmadpourA., RaiszadehR. and DoostmohammadiH.: ‘Effect of stirring on behaviour of double oxide film defects in A356 aluminium melt’, Int. J. Cast Met. Res., 2014, 27, (4), 221–229. doi: 10.1179/1743133613Y.0000000100
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RaiszadehR. and GriffithsW. D.: ‘A method to study the history of a double oxide film defect in liquid aluminum alloys’, Metall. Mater. Trans. B, 2006, 37, (6), 865–871. doi: 10.1007/BF02735007
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BakhtiaraniF. N. and RaiszadehR.: ‘Healing of double-oxide film defects in commercial purity aluminum melt’, Metall. Mater. Trans. B, 2011, 42, (2), 331–340. doi: 10.1007/s11663-011-9480-y
9.
AryafarM., RaiszadehR. and ShalbafzadehA.: ‘Healing of double oxide film defects in A356 aluminium melt’, J. Mater. Sci., 2010, 45, (11), 3041–3051. doi: 10.1007/s10853-010-4308-8
10.
BakhtiaraniF. N. and RaiszadehR.: ‘The behaviour of double oxide film defects in Al–4.5 wt% Mg melt’, J. Mater. Sci., 2010, 46, (5), 1305–1315. doi: 10.1007/s10853-010-4916-3
11.
AmirinejhadS., RaiszadehR. and DoostmohammadiH.: ‘Study of double oxide film defect behaviour in liquid Al–Mg alloys’, Int. J. Cast Met. Res., 2013, 26, (6), 330–338. doi: 10.1179/1743133613Y.0000000067
12.
NateghianM., RaiszadehR. and DoostmohammadiH.: ‘Behavior of double oxide film defects in Al–0.05 wt% Sr alloy’, Metall. Mater. Trans. B, 2012, 43, 1540–1549. doi: 10.1007/s11663-012-9708-5
13.
KhaleghifarF., RaiszadehR. and DoostmohammadiH.: ‘Effect of Ca on the behavior of double oxide film defects in commercially pure aluminum melt’, Metall. Mater. Trans. B, 2015, 46, (2), 1044–1051. doi: 10.1007/s11663-014-0240-7
14.
DispinarD. and CampbellJ.: ‘Critical assessment of reduced pressure test. Part 1: porosity phenomena’, Int. J. Cast Met. Res., 2004, 17, (5), 280–286. doi: 10.1179/136404604225020696
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DispinarD. and CampbellJ.: ‘Critical assessment of reduced pressure test. Part 2: quantification’, Int. J. Cast Met. Res., 2004, 17, (5), 287–294. doi: 10.1179/136404604225020704
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‘ASTM B962-15, Standard test methods for density of compacted or sintered Powder Metallurgy (PM) products using Archimedes’ principle’, 2015, ASTM International, West Conshohocken, PA, USA.
17.
FarhoodiB., RaiszadehR. and GhanaatianM.-H.: ‘Role of double oxide film defects in the formation of gas porosity in commercial purity and Sr-containing Al alloys’, J. Mater. Sci. Technol., 2014, 30, (2), 154–162. doi: 10.1016/j.jmst.2013.09.001
