EN AC-46000 | AlSi9Cu3 non-refined sand casting
| Numeric designation | EN AC-46000 |
|---|---|
| Chemical designation | AlSi9Cu3 |
| State | non-refined sand casting |
| Etching | ungeätzt |
Violent fracture in non-refined AlSi9Cu3(Fe) sand casting.
The silicon precipitates here are unfavorably coarse and stalked, which further reduces the already low elongation at fracture of the alloy. The fracture follows the Si precipitates and proceeds preferentially in the interdendritic Al-Si eutectic, therefore an EDS analysis of the fracture surface shows 50 wt% Si, although the alloy contains only 9% Si. Along the Si precipitations the fracture is brittle, the matrix of Al solid solution in between shows fine dimple fracture. The tensile strength is 265 MPa, but the elongation at fracture is only 0.3%.
