The semi-solid TiB2/6061 composites were prepared by low voltage pulsed magnetic field process

which was remelted partially at 600℃ for 5

10

20 and 30 min

respectively

and then was quenched in the water to reserve semi-solid structure. Finally

the effects of in-situ TiB2 particles on the microstructure of composites were investigated by the optical microscope and graphical analyzer. The experimental results show that in-situ TiB2 particles not only can obviously refine and spheroidize the as-cast microstructure of semi-solid TiB2/6061 composites

but also inhibit evidently grain growth by pinning effect during reheating. At the same conditions

the coarsening rate of the specimens with in-situ TiB2 particulates addition is significantly lower than that in the specimens without TiB2 particulates addition

exhibiting a higher thermal stability than the 6061 matrix alloy

and more suitable for semi-solid thixo-forming process.