EN AW-5019 | AlMg5 intergranular corrosion
| Numeric designation | EN AW-5019 | 3.3555 |
|---|---|
| Chemical designation | AlMg5 |
| State | intergranular corrosion |
| Etching | 5 % NaOH |
Intergranular corrosion is present here, although this alloy is actually very corrosion resistant.
We suspect that this material has been artificially aged by mistake, although the alloy is not age-hardenable. The material was probably annealed at approx. 150-200°C for hours. In the process, Al3Mg2 precipitates from the Mg-saturated Al solid solution, which is insignificant for the strength, but which, due to cohesive precipitates at grain boundaries, makes the material, which is actually very corrosion-resistant, sensitive to corrosion.
corrosion-resistant material sensitive to intercrystalline corrosion.
