Effects of Gd on microstructure and compressive creep behavior of Mg-7Al-1Si alloy were investigated by optical microscopy（OM）

scanning electron microscope（SEM）

X-ray diffraction analysis（XRD）and high temperature compressive creep apparatus.The results show that proper Gd addition can greatly refine the as-cast microstructure and improve the morphology of Mg2Si phase as well as making theβphase more dispersed distribution

so the elevated creep behavior of the alloy is improved.In addition

Al2Gd particulate appears in the matrix.The microstructure and composition of Mg-7Al-1Si alloys are more homogeneous with 1.0%Gd and desirable grain refinement and high creep resistance can be obtained

where the average grain size is decreased from 79.08μm to 39.12μm

and theβphase content are decreased from 10.88%to 6.98%

while the morphology of the Mg2Si phases is changes from coarse Chinese script shape to short rod or fine particle.Accordingly

the creep properties of the alloy are improved greatly.