Modeling of Oxide Bifilms in Aluminum Castings

Porosity is known to be one of the primary
detrimental factors controlling fatigue life and
total elongation of several cast alloy components.
The two main aims of this work are to examine pore
nucleation and growth effects for predicting gas
microporosity and to study the physics of bifilm
dynamics to gain understanding in the role of bifilms
in producing defects and the mechanisms of defect
creation.
In chapter II, a technique based on the combination
of a set of conservation equations that solves the
transport phenomena during solidification at the
macro-scale and the hydrogen diffusion into the pores
at the micro-scale, was used to quantify the amount
of gas microporosity in A356 alloy castings. The
results were compared with published experimental
data. In the reminder of this work, the Immersed
Element-Free Galerkin method is presented and used to
study the physics of bifilm dynamics. The IEFGM is an
attractive technique for simulating FSI problems
involving highly deformable solids.
The analysis should help shed some light on the
IEFGM, and it should be specially useful to
professionals in engineering interested in
modeling processes involving large deformations.

Autorentext

Claudio Pita obtained his BS and his MS in Nuclear Engineeringfrom Instituto Balseiro in Argentina in 2004. In 2005, he workedin the calculation of optimum trajectories for liquid-fuelrockets.In the spring of 2006, he joined the doctoral program atMississippi State University where he obtained his Ph.D. inMechanical Engineering in May of 2009.

Klappentext

Porosity is known to be one of the primarydetrimental factors controlling fatigue life andtotal elongation of several cast alloy components.The two main aims of this work are to examine porenucleation and growth effects for predicting gasmicroporosity and to study the physics of bifilmdynamics to gain understanding in the role of bifilmsin producing defects and the mechanisms of defectcreation. In chapter II, a technique based on the combinationof a set of conservation equations that solves thetransport phenomena during solidification at themacro-scale and the hydrogen diffusion into the poresat the micro-scale, was used to quantify the amountof gas microporosity in A356 alloy castings. Theresults were compared with published experimentaldata. In the reminder of this work, the ImmersedElement-Free Galerkin method is presented and used tostudy the physics of bifilm dynamics. The IEFGM is anattractive technique for simulating FSI problemsinvolving highly deformable solids. The analysis should help shed some light on theIEFGM, and it should be specially useful toprofessionals in engineering interested inmodeling processes involving large deformations.