EN AW-6012 | AlMgSiPb
| Numeric designation | EN AW-6012 |
|---|---|
| Chemical designation | AlMgSiPb |
| State | as-cast condition |
| Etching | 5% NaOH |
A heat-treatable free-machining alloy of medium strength, shown here as-cast. The intermetallic precipitates consist of alpha-AlFeMnSi in the typical ‘Chinese script’ form and Mg₂Si, which turns blue-black during polishing and is partially removed during etching. The dark ‘droplets’ consist mainly of lead and Mg3Bi. Lead and bismuth, which do not dissolve in the aluminium matrix, act as chip breakers and ensure the alloy’s good machinability.
The hardness is 68 HBW 2.5/62.5.
