- By:
- Richter, Nicholas A; Lance, Michael J; Kamath,, Rakesh; Kwon, Sunyong ; Chuang, Andrew; Park, Jun-Sang; Singh, Dileep; Yang, Ying ; Plotkowski, Alexander J; Haynes, James A; Shyam, Amit ; Bahl, Sumit
- Page Number:
- 452-458
- Book Title:
- Light Metals 2026
- Publication Date:
- March 12, 2026
- Publisher Location:
- Springer, Cham, Switzerland
- Conference Name:
- The Minerals, Metals & Materials Society 2026 Annual Meeting & Exposition (TMS 2026)
- Conference Location:
- San Diego, California, United States of America
- Conference Sponsor:
- The Minerals, Metals & Materials Society
- View DOI Listing:
- https://doi.org/10.1007/978-3-032-13832-3_59
Abstract
There is a growing trend to die cast structural automotive components from scrap aluminum sources to reduce embodied energy and cost. However, the ability to include most post-consumer scrap is severely limited due to the sensitivities of current industrial high pressure die cast (HPDC) Al alloys to Fe impurities introduced during the recycling process. This study characterized the surface to centerline microstructural heterogeneity in HPDC plates of Al-7Si-0.5Mn-0.2Mg-xFe (x = 0.18 and 1.0 wt. %) alloys. It was shown using scanning electron microscopy and synchrotron x-ray diffraction that macrosegregation during HPDC enriches secondary phases including Si and (Fe, Mn)-rich intermetallics at the surface. The microstructure evolved with increased Fe impurity, but the evolution was non-uniform in the plate cross-section. Gulliver-Scheil solidification calculations using nominal alloy compositions predicted the experimentally observed phases, but as expected, those calculations could not capture microstructural heterogeneity. The increased fraction of secondary phases and finer microstructure due to more rapid cooling rates at the surface led to higher surface hardness compared to centerline.
