Formation of Iron-Rich Intermetallic Phases in Al-7Si-Mg: Influence of Cooling Rate and Strontium Modification
| Autor: | Arne K. Dahle, Jorge Santos, Anders E.W. Jarfors |
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| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Area fraction Strontium Materials science Morphology (linguistics) Metallurgy Alloy 0211 other engineering and technologies Metals and Alloys Intermetallic chemistry.chemical_element 02 engineering and technology engineering.material Condensed Matter Physics 01 natural sciences Cooling rate chemistry Mechanics of Materials Phase (matter) 0103 physical sciences engineering 021102 mining & metallurgy Eutectic system |
| Zdroj: | Metallurgical and Materials Transactions A. 50:4148-4165 |
| ISSN: | 1543-1940 1073-5623 |
| Popis: | The influence of cooling rate on the formation of iron-rich intermetallic phases during solidification of unmodified and strontium-modified Al-7Si-0.3Mg alloys has been investigated. The effect of strontium on the intermetallic phases was evaluated in unquenched and quenched samples. Samples were quenched before the start of the Al-Si eutectic reaction, along the Al-Si eutectic reaction and just after the end of solidification. The results show that the addition of strontium increased the size of both β-Al5FeSi and π-Al8FeMg3Si6 at low cooling rates. For unmodified and strontium-modified alloys, an increase of cooling rate resulted in a decrease in size of the intermetallic phases, particularly in the strontium modified alloy. In the strontium modified alloy quenched before the start of the Al-Si eutectic reaction, π-Al8FeMg3Si6 appeared as thin platelets at the eutectic cell boundaries. Chinese script-like π-Al8FeMg3Si6 and platelet-like β-Al5FeSi intermetallic phases were observed uniformly distributed in the eutectic regions in the unmodified alloy quenched before the start of the eutectic reaction. Strontium modified semi-solid Al-7Si-0.3Mg castings were produced and the type of intermetallic phase, morphology, size, area fraction and distribution were similar to that observed in the strontium modified alloy quenched before the start of the Al-Si eutectic reaction. |
| Databáze: | OpenAIRE |
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