Casting thermal transforming and semi-solid forming aluminum alloys

摘要

A billet of an aluminum alloy for thermally transforming from a dendritic microstructure to a globular structure and for forming in a semi-solid condition into a shaped aluminum alloy article; the billet having a dendritic microstructure having a grain size in the range of 20 to 250 &mgr;m provided by a solidification rate in the range of 5° to 100° C./sec between liquidus and solidus temperatures when the aluminum alloy is cast into billet; the billet having a dendritic microstructure thermally transformable to the globular structure or non- dendritic structure by heat applied to the billet at a heat-up rate greater than 30° C. per minute to a superheated temperature of 3. degree. to 50° C. above solidus temperature of the aluminum alloy; the billet in the globular structure or non-dendritic structure and in the semi-solid condition having the ability to be formed into the shaped aluminum article.