Small punch assessment of single-crystal turbine blades: The role of crystallographic anisotropy and future perspectives

Nickel-based single-crystal turbine blades, which are widely used in aerospace and power-generation systems, feature thin-walled geometries and exhibit pronounced anisotropic mechanical behavior due to their crystallographic orientations. This paper addresses the increasing demand for creep life assessment of such thin-walled components and investigates the challenges of applying the small punch test to anisotropic materials. Key issues include orientation-dependent mechanical responses, interpretation of complex deformation in disc specimens, and the lack of standardized correlations with conventional creep testing. Future developments are discussed, including detailed analysis of geometric deformation mechanisms, development of anisotropic viscoplastic damage models, and robust data correlation methods between small punch and standard uniaxial creep test results. These advancements are expected to enhance creep life prediction, structural design, and integrity monitoring of thin-walled nickel-based single-crystal turbine blades.