Microstructural damage evolution in two Ni based superalloys subjected to different mechanical loading conditions through quantitative EBSD measurements using Cross-Court software

Abstract

Ni based superalloys are adopted as base materials for critical hot gas path components of gas turbines. Knowledge of the evolution of the microstructure is very important for gas turbine producers in order for them to fully predict component behaviour in service. Quantitative EBSD measurements have been performed to evaluate the local strain condition of the material after test on creep and LCF testpieces of two Ni based superalloys. The Cross-Court software has been used to quantitatively analyse EBSD patterns by means of the cross-correlation method developed by Wilkinson et al. The results of the quantitative analyses enable microstructural characterisation to be completed and the mechanisms that describe material property evolution to be better understood. In addition some measurements have been extended to real components after service and the results have been correlated to FE simulations.