“Silumin” is the name given to aluminium casting alloys with a high silicon content — especially near-eutectic alloys with about 11–13% silicon. The name is common in Russian and Eastern European technical literature and is also heard in the Iranian market.
Why silicon?
Silicon greatly increases the fluidity of the melt, reduces solidification shrinkage and raises wear resistance. At the eutectic composition (about 12.6% silicon), the alloy solidifies at an almost constant temperature, which is ideal for filling thin-walled moulds. More on the melting point of alloys.
Standard equivalents
| Standard | Closest grade |
|---|---|
| UK (BS) | LM6 |
| USA | A413 |
| Europe (EN) | AlSi12 |
An exact match should be confirmed by comparing composition tables. The composition of the LM6 and A413 produced by Almas is given in the aluminium alloy composition table.
Applications
Thin-walled parts, pump and valve bodies, pressure-tight parts, marine components and cookware. For higher strength after heat treatment, Al-Si-Mg alloys such as A356 are a better choice.