Magnesium alloys are widely used in the fields of automobiles

aerospace

and electronic communications due to the various excellent properties.However

the further development and application are limited owing to the poor mechanical properties at room temperature.The performances of the magnesium alloy can be significantly improved by virtue of grain refinement

which is beneficial to subsequent machining.Therefore

the recent development of the grain refinement theory on magnesium alloys as well as the influence of external particles on the grain refinement of magnesium alloys were reviewed.Firstly

the development and problems of traditional magnesium alloy grain refinement theory were expounded.Secondly

the influence and mechanism of external particles commonly used on the grain refinement of magnesium alloy were summarized.Finally

the future potential of high-content nanoparticles in the field of magnesium alloy grain refinement were prospected

providing a reference for further research and development of new and efficient magnesium alloy grain refinement technology.