MELT ING AND CASTING ZIRCONIUM METAL 1, 2

This report deals with the methods for melting and casting zirconium.:Reference is made to the manner of heating, furnace design, crucible materials, and methods of casting. For the experiments, a high-frequency furnace, an arc furnace, and a split-tube graphite-resistor furnace were used. Preference is given the latter for vacuum fusion, while the high-frequency and the arc furnaces are well adapted for melting in a noble gas atmosphere. The crucible materials are discussed, and the melting in graphite and the casting of ingots are described. GENERAL CONSIDERATIONS The melting and casting of zirconium and titanium present many dif-ficulties owing to their high melting point and chemical activity. These two factors restrict the means of heating, the furnace atmosphere, and especially the crucible and mold materials. Titanium will be mentioned only occasionally in this report because of its similarity to zirconium. The use of a nonreacting atmosphere, o of a vacuum, calls for construc