Improved techniques for the production of remelt feedstock for Bridgman directional solidification of aluminium alloys

Some problems associated with the Bridgman directional solidification process are examined, and two improved methods for the Bridgman directional solidification of aluminum alloys are proposed. In the first method, the Bridgman crucible is cemented into the 4-mm bore of a cylindrical boron nitride plunger, such that one end of the crucible is flush with the bottom face of the plunger. This plunger then fits closely within a flat bottomed boron nitride crucible. The second method involves injecting the molten alloy into preheated Bridgman crucibles. Details of both methods are presented. (AIAA)