Abstract: An article, such as a gas turbine engine mixer, is made by providing a mold structure defining a thin-walled, hollow article, and a base metal that is subject to hot tear cracking when cast in a generally equiaxed polycrystalline form, such as Rene' 108 and Mar-M247. The article is fabricated by introducing the molten base metal into the mold structure, and directionally solidifying the base metal in the mold structure to form a directionally oriented structure. The directionally oriented structure may be formed of a single grain or oriented multiple grains.

Abstract: A method and apparatus are provided for making high purity and preferably oxygen free substantially void free and inclusion free copper castings such as billets from high purity copper. The castings are particularly useful to make sputtering targets used in sputtering deposition processes in the fabrication of electronic components. The method comprises melting high purity copper in a covered crucible using a non-contaminating heating source such as a coil induction furnace. The melted copper in the crucible is solidified using a specially controlled cooling procedure wherein the bottom of the crucible is cooled so that molten copper is maintained on top of solidified and solidifying copper until the copper is solidified.