The microstructure of Al-Si-Mg alloys strongly depends on their chemical composition and the heat treatment they undergo during production. The influence of solution heat treatment (SHT) and the addition of Er and Zr on the microstructure of gravity-cast A356 (Al-7Si-0.4Mg) were examined. The reference as-cast microstructure is characterized by the grain size and morphology of eutectic Si, as well as the morphology, area fraction, and chemical composition of the intermetallic compounds. The morphology of eutectic Si is unstable during SHT; the evolution mechanisms can be described using thermodynamic and kinetic models and have been validated using optical and scanning electron microscope (SEM) micrographs. The effect of high-temperature exposure during SHT, on the other hand, plays a minor role on the quantity and morphology of the intermetallic compounds, as demonstrated by optical and SEM micrographs.
|Number of pages||12|
|Journal||Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science|
|Publication status||Published - 1 Jan 2019|
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys