PREPARATION AND THERMAL-STABILITY OF SUPERSATURATED NANOCRYSTALLINE AL-TI ALLOYS

Supersaturated nanocrystalline Al100-xTix alloys were mechanically all oyed in a planetary ball mill. For alloys with x = 5 and 10, a mixture of supersaturated solid solution Al(Ti) and an fee phase coexist whil e a single supersaturated solid solution Al(Ti) was obtained during me chanical alloying for x = 15 and 35. With increasing Ti content, from 5 to 35 at%, the grain size of the Al(Ti) solid solution decreased fro m 40 to 10 nm. The results suggest that fast diffusion along nanocryst alline grain boundaries is the main alloying process. DSC curves and T EM observations indicate that solute atom segregation can thermally st abilize the nanocrystalline solid solutions.