Two passes reverse direction processing was carried out to the thermal sprayed Al2O3 and TiB2particles reinforced aluminum matrix coating on the aluminum alloy surface by frictional stirring processing（FSP）.The results show that after the friction stirring processing

the hole porosity between the original laminated and porous particles almost disappears as a result of the effect of strong pressure and high temperature

and the gap between coating and substrate is narrowed

so the microstructure of the coating become compact and dense after FSPed.After single direction friction stirring processing

coating internal stress is increased

leading to an increase of microhardness from 72 HV to 85 HV.After reverse direction frictional stirring processing

severe plastic deformations can be observed in the area where friction stirring processed dramatically

leading to microstructural evolution

so that the coating exhibits fiber-like flow line structure.The coating microhardness is increased greatly from 72 HV to 150 HV

which is two times higher than the original coating’s.