The effects of Er content on microstructure of Al-Cu-Mg-Ag-Er alloy and electric resistivity

摘要

The Al-Cu-Mg-Ag-Er aluminum alloys with different Er contents were prepared in this experiment. The effects of Er content on microstructures of the as-cast and the extruded alloys, the electric resistivity were researched. The results show that when Er content is below 0.1%, Er has the effect of refining. With Er addition in the range of 0.1%-0.3%, the effect of grain refining to as-cast alloy is obvious. The dimension of second phase particles in extruded alloy decreases, and the number of second phases increases. When Er content is over 0.3%, Er has litter effect on grain refining to as-cast alloy. Er segregates at grain boundaries, and forms AlCuEr. The number of second phase particles in extruded alloy increases, and the dimension is not changed obviously. The AlCu and AlCuEr do not dissolve in the matrix at 350 °C by hot extrusion, which shows good thermal stability of AlCu and AlCuEr. The electric resistivity exhibits decrease first and then increase as the addition of Er.