Creep of Single Crystal Nickel-Base Superalloy Tubes Under Biaxial Tension

An analysis of the statically indeterminate problem of the creep of a biaxially loaded, anisotropic hollow cylinder is presented. The anisotropy of the material leads to a nonuniform axial stress distribution which is evaluated by numerical techniques. Single crystal, tubular specimens of a nickel-base alloy were creep-tested at 1400 deg F with an <001> crystallographic axis nearly coincident with the tube axis in order to evaluate the theoretical analysis. Comparison of predicted and measured creep rates shows fair agreement.