Numerical modeling of crystal growth and solidification experiments carried out under microgravity conditions

Abstract

In this paper first examples for global thermal modeling of microgravity experiments in the field of crystal growth and alloy solidification are presented. The software program CrysVUn is used to simulate alloy solidification experiments carried out in TEXUS sounding rocket missions. Based on this software global thermal models are developed for the furnace inserts Low Gradient Furnace (LGF) and Solidification and Quenching Furnace (SQF) to be operated in the Materials Science Laboratory (MSL) onboard the International Space Station (ISS). These models will be used in order to optimize the process conditions and cartridge designs for the experiments to be carried onboard the ISS

Modeling of industrial bulk crystal growth—state of the art and challenges

“…In the case of TMF, the direction of the Lorentz force is an additional process parameter. Depending on the direction, the solutal enriched parts are either located at the axis or at the outer fringe of the cylindrical sample, with a liquid channel on the axis for downward force (similar to the effect of RMF [11,12]) and on the fringe for upward force. The enriched zones cause a deformation of the mushy zone forming a liquid channel.…”

“…Dependent on the field configuration different flow patterns can be created in the melt in an actively controlled manner. First studies [11,12] concentrated on RMFs, intended to be used in furnace inserts of the Materials Science Laboratory (MSL) of the European Space Agency (ESA) on the International Space Station, which were then compared to the possibilities of TMFs. As microgravity conditions are hard to be realized in earthbound experiments, simulation turns out to be extremely helpful for the preparation of space experiments.…”

First Experiments Using the Materials Science Laboratory on Board the International Space Station

“…The melting point of graphite exceeds by far the LGF maximum design temperature so that the RTC is reusable many times. For further optimization of process parameters global thermal modeling was applied using the software package CrysVUn Version 3.3 (Kurz et al 1999;Friedrich et al 2003). The calculations are based on a detailed two-dimensional axisymmetric finite element model of the LGF and SCA.…”

Modelling of the influence of residual gravity on the segregation in directional solidification under microgravity

“…It is evident that this model is not like a complex 3D code [16,21] or a powerful multi-scale algorithm [22,23], but it is only a simple approach because of the simplifications used. Nevertheless, even if it is simple, the present generic scenario is powerful enough to give a reasonable insight into the global physics in an efficient and economical way.…”