The streamline defects in ZL210A alloy castings were investigated by OM

XRD

SEM

EDS and room temperature tensile testing.The results show that the streamline defects can lead to the slight decrease of tensile strength

elongation

hardness at ZL210A defect sample position by counter-gravity casting

however the mechanical properties of streamline defect samples still meet the use requirements.Crack morphology of sample with streamline defects is characterized by fine dimple structure and rock candy shape.The sample with defects-free is characterized by fine dimple hole.The streamline defect sample is the precursor of brittle fracture.The Cu element in the streamline defects area in ZL210A alloy is less than the standard values

resulting in the decrease of the mechanical properties of ZL210A alloy.