Verbesserte Metallqualität von Aluminium für die Halbzeugherstellung

Abstract

Thanks to the intensive research and development work, carried out especially in the last decade, aluminium reduction plants have various possibilities at their disposal for improving the quality of the metal.
This paper explains the extent of the present knowledge on the subject of aluminium-metallurgy. Of the melt refining processes presently available, it has been shown that preference is given to a combined holding and chlorine treatment and also treatment with salts. The appropriate adoption of these refining processes contributed considerably to solving problems such as susceptibility to blistering, non metallic inclusions and hot-shortness of AlMg alloys.
Whereas it is possible with the newer measuring instruments (hot extraction, Alu-melt tester, telegasmeter) to determine low gas contents with relative accuracy, the determination of low quantities of non metallic inclusions and undesiderable trace elements presented certain difficulties.
An improvement of metal quality can also be achieved by suitable thermal treatment of semi-continuously cast ingots prior to the production of semis in attempts to obtain heterogeneous or homogeneous structures, depending on the type of alloy.
In spite of the rapid break-through of aluminium into the field of commercial metals, the development of metal quality has in many aspects not yet been concluded.