Al-Si alloys

Al-Si alloys

Al-Si aluminium alloys are generally better than other aluminium alloys in terms of casting performance, filling capacity and tendency to thermal cracking and shrinkage due to the small crystallisation temperature interval, the large latent heat of solidification and large specific heat capacity of the silicon phase in the alloy, and the relatively small linear shrinkage coefficient. As a result, the plasticity is better than that of other aluminium alloys, and the only remaining brittle phase can be further improved by metamorphic treatment.

Tests have also shown that Al-Si co-crystals maintain good plasticity at temperatures near their solidification point, which is not the case for other aluminium alloys. There is a certain contradiction between the fact that a considerable number of co-crystals are required in the organisation of a casting alloy to ensure good casting properties and the fact that an increase in the number of co-crystals can make the alloy brittle and reduce its mechanical properties. However, because of the good plasticity of Al-Si co-crystals, it can better take into account the mechanical properties and casting properties of both requirements, so Al-Si alloy is currently applied to the die-casting aluminium alloy. The aluminium desks and chairs, waiting chairs and auditorium chairs that we produce are made of this series of alloys.