Table 1:
Chemical composition of the alloys investigated in % by weight.
| Sample | Si | Fe | Cu | Mn | Mg | Ni | |
|---|---|---|---|---|---|---|---|
| 239 | 10.398 | 0.3548 | 0.005 | 0.2654 | 0.5513 | 0.0038 | |
| 239D | 10.439 | 0.8788 | 0.0229 | 0.3092 | 0.4459 | 0.0062 | |
| Sample | Zn | Pb | Sn | Ti | Sr | Al | Mn:Fe |
| 239 | 0.0039 | 0.001 | 0.0003 | 0.0983 | 0.0369 | rest | 0.748 |
| 239D | 0.0167 | 0.001 | 0.0004 | 0.0253 | 0.0015 | rest | 0.352 |
Figure 1:
(a) Steel mould with a square profile; (b) Casting obtained from the steel mould for tensile specimens.
Figure 2:
The Scheil cooling curve of the non-equilibrium solidification of (a) sample 239 and (b) sample 239D.
Table 2:
The proportions of phase formed during the solidification.
| Phase / Sample | 239 | 239D |
|---|---|---|
| α-Al | 87.00 | 85.20 |
| β-Si (eutectic) | 9.91 | 9.74 |
| α-Al15(Fe,Mn)3Si2 | 0.89 | 1.03 |
| β-Al5FeSi | 1.31 | 3.26 |
| Mg2Si | 0.86 | 0.65 |
| Q-Al5Cu2Mg8Si6 | 0.02 | 0.11 |
Figure 3:
The cooling curve and corresponding derivative of (a) sample 239 and (b) sample 239D.
Figure 4:
Heating (green) and cooling (blue) DSC curve of the sample (a) 239 and (b) 239D.
Figure 5:
Micrographs of (a and b) sample 239 and (c and d) sample 239D.
Figure 6:
Micrographs of sample 239 in (a) as-cast state and (b) T6 heat-treated state and of sample 239D (c) in as-cast state and (d) T6 heat-treated state.
Figure 7:
Hardness of AlSi10Mg alloy and AlSi10Mg(Fe) alloy in as-cast state and after heat treatment.
Figure 8:
Tensile test results for 239 alloys and 239D alloys in the as-cast state and after heat treatment.