The microstructure and properties of domestic and foreign AlSn20Cu-steel bearing bush composites were analyzed comparatively by using OM、SEM、EDS and Vickers hardness tester as well as other equipments in order to better develop the bearing bush composites.The results show that the microstructure of steel matrix is composed of pearlite and ferrite.The ferrite grain size of the foreign material is larger than that of the domestic ones

and the ferrite in the domestic material has obvious deformation.The thickness of alloy layer of foreign bearing bush composites is much smaller than that of domestic ones.The hardness of the two kinds of bearing bush composites is increased from the alloy layer to the interface to the steel matrix

however

the hardness of the steel matrix of domestic material is higher than that of foreign ones

while the interface of domestic materials shows obvious separation after cold bending experiment.