Papers by Author: R. Valdes

Abstract: The solidification and solid-state phase equilibria of four Al-Mg-Si alloys containing 30- 70%Mg and 0.5-3.5%Si, selected on the basis of an isothermal section of the Al-Mg-Si system calculated at 300 °C, have been investigated. Solidification paths of Mg-rich Al-Mg-Si alloys finish on ternary eutectics and the temperatures of two of these eutectic reactions, i.e. L↔(Al)+β+ Mg2Si and L↔(Mg)+γ+ Mg2Si, have been determined to be at ~ 448 °C and ~ 436 °C respectively by DTA. The characteristic temperatures recorded on the DTA curves are analysed and a linear relationship is found between the peak temperature and the square root of the scanning rate.

Abstract: The MICAST research program focuses on a systematic analysis of the effect of convection on the microstructure evolution in cast Al-alloys. The experiments of the MICAST team are carried out under well defined thermally and magnetically controlled, convective boundary conditions and analyzed using advanced diagnostics and theoretical modeling, involving phase field simulation, micro-modeling and global simulation of heat and mass transport. The MICAST team uses binary, ternary and technical alloys of the Al-Si family. This paper gives an overview on recent experimental results and theoretical modelling of the MICAST team.