3D characterization of the propagation of liquid metal embrittlement inner cracks during tensile shear testing of resistance spot welds

An X-ray tomography setup is developed in this work in order to characterize liquid metal embrittlement (LME) cracks and internal defects in 3D in homogeneous advanced high strength steel resistance spot welds, non destructively. For the first time, the propagation of the LME inner crack could be monitored in the course of ex situ tensile shear loading. While propagating in a stable way through the sheet thickness in the vicinity of the weld nugget, the LME inner crack does not modify the final fracture path, all investigated welds failing at the faying surface (full interfacial failure type).