Authors: Sofiane Terzi Luc Salvo Michel Suéry Arne K Dahle Elodie Boller
Publish Date: 2013/07/11
Volume: 48, Issue: 21, Pages: 7422-7434
Abstract
In conventional melting experiments of pure monocrystalline metals the phase transformation starts at the sample surface and progresses inwards according to thermal gradients In solutionized alloys traces of internal melting are usually observed after reheating and quenching from the semisolid state The formation and development of these liquid pockets are not fully understood despite their significance in semisolid processing where the formability is greatly influenced by the distribution of liquid within the feedstock material In situ Xray microtomography was performed in this study to shed light on this phenomenon We report in detail the melting and isothermal holding of a model binary alloy where a remarkable number of liquid droplets were observed to develop and coalesce Various computational tools have been used to study their statistical evolution as well as the local ripening mechanisms involved We analysed an interesting case of particle coarsening which differs from classical case studies by the fact that the fastdiffusing liquid phase is entrapped within the slowdiffusing solid mediumARC CoE for design in light metals is acknowledged for its financial support In situ Xray microtomography was performed in the framework of the project ANR08BLAN082 318938 SIMUZAL supported by the Agence Nationale de la Recherche which is also gratefully acknowledged The authors wish to thank all staff members of the ID19 beamline of ESRF Grenoble for their technical support
Keywords: