Effect of trace rare earth element Er on high pure Al

The influence of trace Er addition on high pure aluminum was studied by mechanical properties measurement hardness measurement, optical microscope, transmission electron microscope and energy spectrum analysis. The results show that minor Er in the studied alloy exists in the form of Al3Er, only a few of Er in alpha-Al based solid solution. Primary Al3Er particles formed during solidification were often found at the center of aluminum grains and acted as heterogeneous nucleus, also increased the rate of nucleation therefore the grain are remarkably refined. Trace Er addition to high pure aluminum is able to increase the mechanical properties of high pure At, which is caused by fine grain strengthening, substructure strengthening and precipitation strengthening. The recrystallization temperature of Er-doped aluminum increases above 50 degreesC, which is caused by the pinning effect of highly dispersed fine Al3Er precipitates on dislocations and sub-grain boundaries.