As-cast microstructure and ambient mechanical properties of Mg-5Sn with different Sn additions（as 0

0.3%

1.0%

1.5%

2.0% and 3.0%） were investigated by SEM（scanning electron microscope）

EDS（energy dispersive spectrometer） and XRD（X-ray diffraction） as well as tensile testing

meanwhile

the creep behavior of the alloy was examined with loading of 35 MPa at 175℃.The results reveal that with Sr addition

MgSnSr heat resistant phase with rod and acicular shape can be observed in the Mg-5Sn alloy.With increasing in Sn addition

numbers of MgSnSr phase are increased

and Mg2Sn phase content is decreased.Ambient mechanical properties of the Mg-5Sn alloy can be improved with Sr addition

which is attributed to the refining effects of minor Sr on grain size and dispersed strengthening effects of MgSnSr phase.When Sr addition is 0.3%

tensile strength and elongation of the Mg-5Sn alloy reach 165MPa and 10.4%

respectively

exhibiting desirable mechanical behavior.In addition

heat resistance of the Mg-5Sn alloy can be greatly improved with increasing in Sr contents.Steady creep rate of the alloy with 3% Sr addition is decreased by approximately 50%.