Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography

• DOI: 10.1016/j.actamat.2023.119421
• Publication Date: 2023-10-10T11:04:50Z
• Authors: Insung Han; Shikang Feng; Fabian Wilde; Patrick S. Grant; Enzo Liotti
• Keywords: Tearing; Shrinkage

Hot tears can arise during the late part of alloy solidification because shrinkage isolated liquid as it turns to solid and may have a catastrophic effect on cast tensile properties. Although there are correlations suggest hot tear sensitivity casting conditions, they do not capture influence microstructure tearing, such second-phase particles or intermetallic compounds (IMCs) commonly present in engineering alloys. We use situ X-ray radiography quantify formation growth behaviour Al-5Cu Al-5Cu-1Fe alloys solidification. An automated detection, tracking merging algorithm is developed applied reveal role Fe-rich IMC particles, typical recycled alloys, behaviour. These defects termed here basis their complex, extended inter-connected morphology, distinct from more rounded porosity. also visualise velocity interdendritic flow driven by shrinkage, estimate pressure changes due shrinkage. tearing starts at lower fraction when IMCs reduced flow, spatially homogeneous, less clustered numerous. show that largest, most damaging form many events, enhanced presence IMCs.