Mechanical behavior prediction of additively manufactured components based on defect evolution observation by synchrotron radiation X-ray tomography

Abstract

Defects including inclusions and voids significantly affect the mechanical properties of the additive manufacturing materials. It is necessary to precisely capture the defects and determine their hazardous effects on material mechanical properties. In this paper, a damage model is developed to describe the nucleation, growth, and coalescence of voids in additive manufacturing materials, revealing the nature of true stress drop. In order to characterize the defect morphology and depict the defect evolution, an in-situ tensile test with synchrotron radiation X-ray topography (SRXT) is carried out. Statistical reconstruction of the initial voids morphology are used as input for the established damage model. Furthermore, in light of the epistemic uncertainty in the process of defect reconstruction in SRXT, Bayesian framework is adopted for parameter estimation. Finally, the above model is verified by the data form 3D defect reconstruction and the uniaxial tensile test, where the constitutive behavior as well as its scatter are well captured. This work contributes to the depiction on damage evolution and the correspondingly affected deformation performance, which can be useful in material design and defect control for additive manufactured load-bearing structures.