ZA27 alloy ingot containing 0.2% or 0.5% Zr was prepared

and the prepared alloy was treated by solid solution at 370 ℃ for 12 hours and artificial aging at 100℃.The results show that 0.2% Zr can apparently modify the ZA27 alloy by transforming developed dendrite into fine rosette grain

however

0.5% Zr content can fade the modification effects as a result of generation of coarse rod-like Al3Zr phase.After solid solution treatment

supersaturated primary α’

phase is transformed into fine（α+η） phase in the alloy

meanwhile

a little CuZn5 phase is found in α grain boundary.α grain in the alloy with 0.2% Zr addition exhibits more uniformity and fine.In addition

Zr modification can significantly improve the peak hardness of the aged alloy

and postpone the corresponding aging time at 100 ℃.