Al

2

O

3

particle and Al3Zr particle reinforced aluminum matrix composites were prepared in Al-Zr（CO3）2 system by magnetic-chemical in-situ reactive synthesis method.Crystal morphology and growth mechanism in microstructure of the composites were investigated by XRD（X-ray diffraction）

SEM（scanning electron microscope）and TEM（transmission electron microscope）.The results reveal that created Al

2

O

3

and Al3Zr reinforcement with average size in 90～120 nm are uniformly distributed in the matrix alloy

in which in-situ Al3Zr phase exhibits particle

bulk

lamellar or acicular shape.In Al-Zr（CO3）2 system

under the condition of pulsed magnetic field

Al3Zr phase exhibits particle

bulk shape

lamellar shape and acicular shape with reaction at 850℃

900℃

950℃and 1000℃

respectively.There exists growth facets on the surface of the Al3Zr phase

and clear twin face and formed concave groove can be observed in the crystal

where twin face is（114）and twin crystal orientation is [221].The growth morphology of Al3Zr phase is closely relative to the creation and numbers of the twin crystal.In-situ equiaxed Al

2

O

3

phase can be observed in the composites

which is weakly dependent on the reactive temperature.