A hybrid-welded joint that consists of parts produced by additive manufacturing (AM) and casting can help overcome the current part size limitation associated with the AM process [1]. These hybrid-welded joints are characterized by a wide range of microstructural heterogeneities across various length scales along the entire joint length, which influences the fatigue behavior of the joint. Fatigue failure in the welded joints is mostly a local phenomenon driven by impurities and microstructural heterogeneities. Therefore, an in-depth understanding of the effect of microstructure on the properties is essential to apply the hybrid-welded joint in safety-critical industrial applications. The present study aims to predict the fatigue behavior of each joint region using a micromechanical model and the entire joint's fatigue lifetime by considering the behavior of each region using a suitable macro modeling framework. A hybrid constitutive framework consisting of a crystal plasticity and a J2-plasticity model for the Al and Si-rich phase, respectively, is applied to the dual-phase synthetic microstructures to predict the fatigue behavior of each welded region. The applied micromechanical modeling framework can accurately predict the mechanical behavior of each region [2] and can help establish the structure-property relationship. This relationship can be used to tailor additional heat treatment processes in order to modify the microstructure of each joint region, thereby improving the fatigue lifetime of the hybrid-welded joint.

References

[1] M. Krochmal et al., J Mater Res (2022).

[2] A. Nammalvar Raja Rajan et al., Materials 15, 5562 (2022).