Investigation of Dynamic Fracture Behavior of Additively Manufactured Al-10Si-Mg Using High-Speed Synchrotron X-ray Imaging

Abstract

The dynamic tensile properties of additively manufactured (AM) and cast Al-10Si-Mg alloy were investigated using high-speed X-ray imaging coupled with a modified Kolsky bar apparatus. A controlled tensile loading (strain rate = 750 s−1) was applied using a Kolsky bar apparatus and the deformation and fracture behavior was recorded using the high-speed X-ray imaging setup. The recorded high-speed frames were used to identify the location of the critical flaw and to capture the dynamics of crack propagation. In all experiments, the critical flaw was located on the surface of the specimen. The AM specimens showed significantly higher crack propagation speed, yield strength, ultimate tensile strength, strain hardening coefficient, and lower ductility compared to the cast specimens under dynamic tension. The microstructures of the samples were characterized by synchrotron X-ray tomography. The correlation between the dynamic fracture behavior of the samples and the microstructure of the samples was analyzed and discussed.KeywordsDynamic fractureLaser powder bed fusionKolsky barHigh-speed X-ray imagingAluminum alloys