Research Article
Microstructural Characterization of Beryllium Treated Al-Si Alloys
Table 3
Main reactions observed from thermal analysis data of alloys A1, C3BS, and C3B.
| | Alloy code | Temp. (°C) | Reaction [21] |
|
A1
0.09%Fe-0.4%Mg | 612 () | Formation of Al-dendritic network | | 569 () | (i) Precipitation of Al-Si-eutectic phase
(ii) Precipitation of posteutectic β-Al5FeSi phase | | 561 () | Transformation of β-phase into π-Al8Mg3FeSi6 phase | | 546 () | (i) Precipitation of Mg2Si
(ii) Quaternary eutectic reaction |
|
C3BS
0.6%Fe-0.8%Mg-0.05%Be-0.02%Sr | 609 () | Formation of Al-dendritic network | | 568 () | Formation of preeutectic β-Al5FeSi phase | | 561 () | (i) Precipitation of Al-Si-eutectic phase
(ii) Precipitation of posteutectic β-Al5FeSi phase | | 550 () | (i) Transformation of β-phase into π-Al8Mg3FeSi6 phase
(ii) Precipitation of Mg2Si | | 540 () | Quaternary reaction |
|
C3B
0.6%Fe-0.8%Mg-0.05%Be | 613 () | Formation of Al-dendritic network | | 611 () | Formation of Be-Fe phase | | 560 () | (i) Precipitation of Al-Si-eutectic phase
(ii) Precipitation of posteutectic β-Al5FeSi phase | | 551 () | (i) Transformation of β-phase into π-Al8Mg3FeSi6 phase
(ii) Precipitation of Mg2Si | | 539 () | Quaternary reaction |
|
|
Quaternary reaction, L → Al + Si + Mg2Si + Al8Mg3FeSi6.
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