Abstract: The disclosed method includes, from a topographic map showing, for a set of points {x} located in a midplane of the fracture surface, a height of the fracture surface h relative to the midplane: a step of determining, for each point x on the topographic map, a quantity ?? representative of an average difference in height)I?xI?? between the height h of the fracture surface at point x in question and the height h of the fracture surface at one or more points {x+?x} located inside a circle of radius ? centered on point x in question, a step of determining, according to a test distance ?r, a spatial correlation function C? representing a spatial correlation between points {x} and points {x+?x} such as I?xI=?r, and a step of determining a correlation length ? from the spatial correlation function C?.

Abstract: The disclosed method includes, from a topographic map showing, for a set of points {x} located in a midplane of the fracture surface, a height of the fracture surface h relative to the midplane: a step of determining, for each point x on the topographic map, a quantity ?? representative of an average difference in height)I?xI?? between the height h of the fracture surface at point x in question and the height h of the fracture surface at one or more points {x+?x} located inside a circle of radius ? centered on point x in question, a step of determining, according to a test distance ?r, a spatial correlation function C? representing a spatial correlation between points {x} and points {x+?x} such as I?xI=?r, and a step of determining a correlation length ? from the spatial correlation function C?.

Abstract: A casting process for an aluminum alloy containing at least about 0.1% of Mg and/or at least about 0.1% of Li in which a liquid surface of the alloy is put into contact with a dried gas including at least about 2% of oxygen by volume and with a water partial pressure lower than about 150 Pa throughout most of the solidification process is described. The process makes it possible to cast most oxidable aluminum alloys, in particular aluminum alloys containing magnesium and/or lithium, without using additives such as beryllium and/or calcium and without using expensive devices and/or gases, to obtain cast ingots generally free from surface defects and pollution, in complete safety.

Abstract: The present invention relates to a casting process for an aluminum alloy containing at least about 0.1% of Mg and/or at least about 0.1% of Li in which a liquid surface of said alloy is put into contact with a dried gas including at least about 2% of oxygen by volume and with a water partial pressure lower than about 150 Pa throughout most of the solidification process. The invention makes it possible to cast the most oxidable aluminum alloys, in particular aluminum alloys containing magnesium and/or lithium, without using additives such as beryllium and/or calcium and without using expensive devices and/or gases, to obtain cast ingots generally free from surface defects and pollution, in complete safety.

Abstract: The invention relates to a casting process for an aluminum alloy containing at least about 0.1% of Mg and/or at least about 0.1% of Li in which a liquid surface of said alloy is put into contact with a dried gas including at least about 2% of oxygen by volume and with a water partial pressure lower than about 150 Pa throughout most of the solidification process. The invention makes it possible to cast the most oxidable aluminum alloys, in particular aluminum alloys containing magnesium and/or lithium, without using additives such as beryllium and/or calcium and without using expensive devices and/or gases, to obtain cast ingots free from surface defects and pollution, in complete safety.