| 摘要 |
In the production of safety components for vehicles, especially motor vehicles, by dead mould casting, the existing limits for the amount of impurities, which the feedstock unavoidably contains when using recycled metal from scrap vehicles, are narrow. This is why a considerable proportion of primary aluminium is required for components for the automotive industry in order to keep the residual impurity content low. In the method according to the invention, on the other hand, larger amounts of nonmetallic impurities can be tolerated and, in particular, a high iron content of over 0.2% can remain in the metal since the special solidification conditions and the very fine grain size nevertheless allow the production of a ductile, high-strength, heat-treatable and weldable dead mould casting. According to the prior art, this is impossible at present on the basis of impure secondary metal. The method according to the invention relates not only to melts which have been produced completely from secondary metal but also those which contain a significant proportion of secondary metal.
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