The effects of Ag content on microstructure and properties of Mg-4 Zn-0.5 Sr alloys were investigated. The microstructure

tensile fracture morphology

mechanical properties and phase of the alloy were analyzed by optical microscope（OM）

scanning electron microscope（SEM）

universal testing machine

X-ray diffraction（XRD） and energy dispersive spectrometer. The results show that the microstructure of the alloy is mainly composed of α-Mg matrix

dotted MgZn phase of staggered distribution

elongated Mg

17

Sr

2

phase and short coarse Mg

4

Ag phase distributed at grain boundaries. With the increase of Ag content

the grain size of the alloy is increased firstly and then decreased

and the mechanical properties of the alloy is increased firstly and then decreased. When Ag content is 0.5%

the grain size of the alloy reaches 83.28 μm

and the alloy presents desirable mechanical properties with maximum tensile strength of 182 MPa

yield strength of 102 MPa and elongation of 13.81%.