|About this Abstract
||2019 TMS Annual Meeting & Exhibition
||Solidification Processing of Light Metals and Alloys: An MPMD Symposium in Honor of David StJohn
||Heterogeneous Nucleation Sequence at the Interface of TiB2 to Form Al
||Jiehua Li, Peter Schumacher
|On-Site Speaker (Planned)
A correlative atomic scale high angle annular dark field imaging and electron energy loss spectroscopy in the dedicated aberration corrected scanning transmission electron microscope (STEM) as well as atom probe tomography is used for the characterization of the heterogeneous nucleation interface of TiB2 in three distinct material systems in order to more accurately elucidate the partitioning of non-interacting solute elements (e.g. Ti, Cu and Ag) to TiB2. Firstly, as a reference, the heterogeneous nucleation interface of TiB2 in a commercial Al-Ti-B grain refiner (i.e. Al-5Ti-1B) was studied. Secondly, the grain refinement of Al-Cu based alloys with varying Ti content (but with identical growth restrictions to the reference case) was investigated. Thirdly, a commercial Al-Cu-Mg-Si-Mg alloy was also investigated. The effect of the solidification path (i.e. peritectic reaction and subsequent peritectic transformation) on the observed nucleation phenomena is also discussed. Our results elucidate heterogeneous nucleation subsequences on TiB2 to form Al.