Crystal Orientation Optimization of Nickel-based Single Crystal Turbine Blade

This paper presents a method to optimize crystal orientation of Nickel-based single crystal turbine blade. Total strain range, crystal orientation and temperature range have effect on the low cyclic fatigue life of Nickel-based single crystal superalloy, on other invariable thermo-mechanical cycle conditions. The experiment data of many concerned literatures were analysed and how crystal orientation effect single crystal blade damage and fatigue life was derived. The evaluating method for fatigue life of single crystal superalloy was proposed The 3 dimensional Nickel-based single crystal turbine blade was modeled in MARC program and this finite element model was capable of accounting for primary and secondary crystal orientation variation. Effects of variation in crystal orientation on blade fatigue life were studied based on finite element model with 68 material coordinate systems, by constitutive equation based on crystal slip systems. Result presented demonstrates that control of primary and secondary crystal orientation has the potential to significantly increase turbine blade resistance to fatigue without adding additional weight or cost