Thermal Fatigue of Turbine Alloys with Special Reference to PWA 663 Nickel-Base Alloy

Thermal fatigue and bow evaluation of an alloy for aircraft gas turbine applications are considerably enhanced by the use of miniature airfoil specimens, which provide a rapid means of sorting alloy compositions. This paper discusses the merits of the test and specifically in relation to the newly developed PWA 663 nickel base alloy. The procedure in testing this alloy, which proves to be superior to cobalt base alloys, is fully described and the results are given together with those of a comparative strain cycling test.