Effect of rare earth La and Ce on microstructure of ZL201 alloy

Abstract：The effect of rare earth and heat treatment on microstructure of ZL201 alloy was studied.The experimental results show that the grain size of ZL201 alloy was refined with the increasing addition of La and Ce, and the black plate precipitated phase T (Al12CuMn2) was reduced.Some discontinuous eutectic structures were distributed homogeneously at grain boundary.When the addition of rare earth was added to 0.5%, the modification came to the best.With more addition of rare earth, over modification was occurred and grain size became worse.The alloy modified by 0.5% rare earth and after T5′heat treatment, the continuity of grain boundary was broke in and skeletal intermetallics appeared at grain boundary.Inner grain, strengthening phase was also precipitated.The effect treated by T5 was better than that of T5′, and more black fine hard phases were precipitated.The strengthening phase θ′ was refined obviously.

Keyword：ZL201;rare earth;grain size;