Mechanism of nucleation and growth of hydrogen porosity in solidifying A356 aluminum alloy: an analytical solution

Formation and reduction of hydrogen porosity during selective laser melting of AlSi10Mg

“…Hence, if only a part of that hydrogen contamination of the powder ends up in the melt pool, the nucleation and growth of the hydrogen pores starts in the melt pool. Li and Chang (2004) described the mechanism of nucleation and growth of hydrogen porosity in solidifying aluminum alloy in with an analytical solution. In order to reduce the hydrogen porosity, the hydrogen, especially the moisture as a hydrogen source, has to be reduced.…”

Alloy composition and metal/mold heat transfer efficiency affecting inverse segregation and porosity of as-cast Al–Cu alloys

“…Gas thermal conductivity [27] k G f(T) W m À1 K À1 Gas specific heat [27] C G f(T) J kg À1 K À1 Nominal concentration of hydrogen [29] C (2) The inverse segregation region can contain microporosity and the hydrogen is the only gas considered. (3) The solid phase is stationary, i.e., once the solid has formed it has zero velocity.…”

“…Several models have been developed in order to better understand pore formation [18,[26][27][28][29][30][31]. Hydrogen which is initially in the molten alloy can be either redistributed in the liquid and solid phases or expelled into the gas phase by forming a hydrogen bubble [29].…”

Cellular Automaton Modeling of Microporosity Formation during Solidification of Aluminum Alloys

“…2,3) Because of the fundamental and practical importance, extensive efforts have been devoted to develop models for predicting the occurrence of porosity in castings. As reviewed by Lee et al 2) and Stefanescu,3) most models, [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] such as analytical solutions, criteria functions, Darcy's law coupled with the conservation and continuity equations, and gas diffusion-controlled pore growth models, focus on predicting the amount of porosity in a solidified casting, but without graphical morphology output.…”