Effects of streamline defects in practically produced ZL205A alloy castings on mechanical properties

microstructure

composition and melting point of the alloy were investigated by SEM（scanning electron microscope）

EDS（energy dispersive spectrometer）and DSC.It is found that the streamline defects have a little effect on the mechanical properties of the alloy castings

and the major can meet the requirements of I grade.Crack morphology of samples with streamline defects is characterized by fine dimple hole

exhibiting acceptable toughness.The matrix alloy is mainly composed of Al solid solution

and Ti

V

Mn

Cu element as well as grey-white Al3Ti plate.Compared with those of samples without streamline defects

peak temperature of initial melting

phase and final melting of samples with streamline are increased by 13 ℃

5℃ and 6℃

respectively.