Microstructure of laser cladding nickel-based superalloy: characterization, finite element modeling, and fatigue analysis

Abstract

Abstract After laser cladding, the mechanical response of nickel-based single crystal superalloy is more complex when the loading direction is perpendicular to the columnar grain growth direction. In order to understand the deformation at grain level, a representative volume element (RVE) model based on the randomness of columnar grain texture was established for DD6 single crystal alloy, and the finite element model simulation of crystal plasticity (CPFEM) was performed. The results show that the stress and strain responses of the cladding microstructure are related to the grain distribution. The orientation difference between columnar grains in the epitaxial growth microstructure leads to non-uniform deformation and local stress concentration. The greater the crystal orientation difference is, the more obvious the stress concentration phenomenon is. On this basis, the statistical standard deviation of strain component is chosen to represent the fatigue damage of material, and the relationship between the statistical standard deviation of strain component and the external load strain is studied, which has certain reference value for the fatigue damage research of micro-cladding.