Patent ID: 9566643
Date: 2017-02-14
CPC Classifications: B22D,C22C

Claim:
1. A method of casting an ingot of an aluminium alloy comprising lithium, the ingot having a length L, width W, and thickness T, the method comprising the steps of: (a) preparing at least two molten aluminium based alloys in separate furnaces, a first alloy with a composition A which is free from lithium as purposive alloying element, and a second alloy with a composition B which comprises lithium as purposive alloying element; (b) transferring the first alloy via a metal conveying trough from a first of said furnaces to a casting station; (c) initiating the start of casting an ingot and casting the first alloy to a required length L (d) subsequently transferring the second alloy via a metal conveying trough from a second of said furnaces to the casting station while simultaneously stopping the transfer of the first alloy to said casting station; (e) casting the second alloy from an end surface of the cast first alloy at length L (f) cropping the cast ingot at a bottom thereof at a length that is greater than or equal to the cast length L