Coupled thermo-electro-mechanical modeling of thermal fatigue of single-crystal corset samples


The possibilities of predicting thermal fatigue durability for single crystal on the base of coupled thermo-electro-mechanical finite-element modeling with using of deformational criterion and microstructural models of inelastic deformation are investigated. Results of thermal and stress-strain state simulations of single-crystal corset specimens under cyclic electric heating and cooling are presented and discussed. Comparison of computational results with experimental data for various single-crystal nickel-based superalloys demonstrates a good accuracy in the prediction of the number of cycles for the macrocrack initiation. The influence of maximum / minimum values of temperature in cycle and delay duration on the number of cycles for the macrocrack initiation are analyzed. The simplified analytic approximation for thermal fatigue durability curves is proposed.