Creep behavior of nickel-based single crystal superalloy under gradient loading

Nickel-based single crystal creep's properties are commonly calculated according to the rupture strength under constant load. The creep deformation of turbine blades is not only occurred under constant loading but also the variable loading. The influence of variable load on creep deformation should also be considered. Based on this background, in the present study, gradient loading creep tests of DD6 nickel-based single crystal are carried out under two modes. Take load and holding times into account, the creep characteristics and microstructure evolution is studied. The results show that the load and holding time have significant effects on the creep properties of nickel-based single crystals. The change of load induces an instantaneous jump on the creep deformation and strain rate. The holding time of each loading stage mainly affects the evolution of the internal microstructure of nickel-based single crystal. The research on creep behavior of nickel-based single crystal under gradient load in this paper not only enriches the service performance evaluation of nickel-based single crystal under complex environment but also provides a reference for material design and performance optimization.

Automated summary

The study on gradient loading creep behavior of nickel-based single crystal revealed that load and holding time significantly affect creep properties, with load changes causing instantaneous jumps in creep deformation and strain rate, while holding time mainly influencing the evolution of internal microstructure.