Abstract: In the production of alloys, particularly Al alloys, by a continuous casting process a supplementary alloy stream is continuously fed into a main metal stream running to the casting mould. The supplementary alloy stream preferably amounts to 1-20% of the main metal stream and has a liquidus temperature above the temperature of the main metal stream so that on contact with the main metal stream, intermetallic phases are precipitated very rapidly as a result of the high chill rates.This mode of casting reduces the risk of coarse primary particles when casting alloys of high alloying element content. The supplementary alloy stream need not be based on the same metal as the main metal stream. The method is considered suitable for the addition of various metals, such as Zr, Mn, Cu, Fe, to aluminium and aluminium alloys to overcome a variety of difficulties and to produce alloy products of improved properties.