The effects of Y addition（0.02

0.05

and 0.10%）on microstructure

mechanical properties

electrical properties of Al-0.16 Zr alloy were investigated.The results indicate that 0.05%and 0.10%Y addition can remarkably refine the grain size

and within range of the Y addition

the refinement becomes more effective with Y addition increase.During the aging treatment of as-cast alloys at 350℃

the Y addition leads to obvious age hardening

and the higher Y addition is

the shorter the peakaging time is.However

the electrical conductivity is reduced due to existence of lattice mismatch distortion field

which is attributed to the accelerated precipitation of coherent Al3 Zr particles.Moreover

in the aging treatment of rolled alloys

hardness is still enhanced with Y addition

in spite of annealing softening caused by reduction of dislocation density.In comprehensive consideration

the rolled Al-0.16 Zr-0.10 Yalloy obtains the optimal hardness and electrical conductivity combination after aged at 350℃for 30 h.