Effects of RE element Nd on microstructure and mechanical properties of AZ80 magnesium alloy were analyzed by OM（optical microscopy）

XRD（X-ray diffraction）and SEM（scanning electron microscopy）.The as-cast microstructure of AZ80 alloy consists ofα-Mg matrix andβ-Mg

17

Al

12

phase which appears in form of coarse network at grain boundaries.With addition of Nd

coarse continuousβ-Mg

17

Al

12

phase is refined and becomes discontinuous

and a new rod-shaped Al

11

Nd

3

phase and blockshaped Al

2

Nd phase occur in alloy.Under as-cast conditions

with the increase of Nd addition

the mechanical properties of AZ80 magnesium alloy is increased firstly and then decreased.With the Nd content of 0.9%

the tensile strength

yield strength and elongation of the magnesium alloy are increased to 205 MPa

135 MPa and 7.5%

respectively.During aging treatment

the addition of Nd can suppress the discontinuous precipitation of plate-likeβ-Mg

17

Al

12

phase at grain boundaries

and the time of reaching the peak hardness is delayed.After T6 heat treatment

the tensile strength

yield strength and elongation of AZ80-0.6Nd alloy are increased to 221 MPa

164 MPa and 4.1%

respectively.