Study on mechanical properties of Ni-based superalloys coupled with quantified weights of multi-modal microstructure damage evolution

A method for predicting fatigue life using damage variables coupled with multi-modal microstructure damage evolution was proposed after analyzing the weights of the multi-modal microstructure of directionally solidified Ni-based superalloys DZ125 in this paper. Mechanical property tests and metallographic observation tests were carried out, and the microstructure weights of the superalloys were quantified using principal component analysis (PCA) and entropy-based inter-criteria correlation (CRITIC) weight analysis. The relationship between mechanical properties and multi-modal microstructures of the superalloys was analyzed, and fatigue life was predicted using damage variables coupled with multi-modal microstructure damage evolution. The weights of multi-modal microstructures of Ni-based superalloys and the influence of multi-modal microstructural damage evolution on mechanical properties were quantified by taking into account the interactions among the microstructural factors and their combined effects, which were important references for the design and processing of the superalloy as well as the prediction of mechanical properties.