TITANIUM AND ZIRCONIUM CASTING DEVELOPMENTS BY THE U.S. BUREAU OF MINES

Casting studies conducted by the U. S. Bureau of Mines laboratory at Albany, Oreg., are described which demon strate that titanium and zirconium castings weighing up to 75 lb can be produced successfully without any contamination. Two types of consumable-electrode arc-melting furnace have been used: bottom-pour crucible and tilting crucible models. Skull melting in water- cooled copper crucibles prevents contamination by crucible materials. Massive scrap, clean chopped machine turnings, and sponge can be fabricated into satisfactory electrodes. Mold materials that have proved satisfactory include machine graphite, rammed granular graphite, and copper or aluminum. (auth)