Significant increases in high temperature strength capability have been achieved in a second-generation nickel-base single crystal alloy designed for advanced military and commercial turbine airfoil applications. This new alloy, designated PWA 1484, offers a 50°F improvement in metal temperature capability (creep-rupture strength, thermal fatigue resistance, and oxidation resistance) over PWA 1480, the first nickel-base single crystal turbine alloy to enter production. PWA 1484 represents the first use of rhenium in a production single crystal superalloy. The alloy properties have been fully characterized and demonstrate an outstanding combination of high-temperature creep and fatigue strength as well as excellent oxidation resistance. Production processing of single crystal PWA 1484 castings has shown that the alloy has good castability and a wide solution heat treatment range. The superior properties of PWA 1484 have been confirmed through extensive engine testing. Superalloys 1988 Edited by S. Reichman, D.N. lhhl, G. Maurer, S. Antolovich and C. Lund The Metallurgical Society, 1988