Aluminium investment castings are used where low weight, thin walls and complex geometry have to be combined, for example in housings, brackets and fluid-carrying parts. The Al-Si7Mg family dominates because it combines good fluidity with useful strength and ductility after solution treatment and artificial ageing.
Grades in this family
| Grade | Type | UNS | Standard | Tensile strength Rm, min. (MPa) | Yield strength Rp0.2, min. (MPa) |
|---|---|---|---|---|---|
| A356.0 | Al-Si7-Mg heat-treatable casting alloy | A13560 | ASTM B618/B618M (investment castings); AA A356.0 | — | — |
Minimum values (or ranges) for separately cast test bars as specified in
Casting and processing considerations
Mechanical properties depend strongly on melt quality (hydrogen and oxide content), iron level and local solidification rate; values from separately cast test bars and from the casting itself can differ. The ceramic shell cools aluminium slowly compared with a metal die, which should be considered when property requirements are taken over from other casting processes.
Reference data compiled from the cited standards for orientation. Always work from the current edition of the governing specification; values are not a guaranteed LOSTWAX delivery specification.