Abstract: Aluminium-lithium alloys were melted and cast in the type ZG-25 vacuum medium frequency induction melting furnace. The vacuum was 66pa. The reactions of thv, melt of aluminium-lithium alloys with the crucibles, which were made of commercial graphite, high purity graphite,or aluminium oxide, and with wash of zinc oxide or boron nitride were investigated. The method of controlling lithium content of the melt under vacuum condition was founded. Without using titanium-boron grain refiner, the ingot has a fine cquiaxed grain structure, its composition was homogeneous, and no inclusion was found. The amount of trace elements, such as hydrogen, sodium, and potassium, dropped remarkably under vacuum melting.

Key words: aluminium-lithium alloy, vacuum melting, crucible material control of lithiu m content, quality of ingot