An experimental and modeling study on the role of damage cascade formation in nanocrystalization of ion-irradiated Ni52.5Nb10Zr15Ti15Pt7.5 metallic glass

We have shown that I MeV Ni+ ion irradiation can cause nanocrystal formation in Ni52.5Nb10Zr15Ti15Pt7.5 metallic glass (MG). The process requires precipitate formation and subsequent crystal growth within the precipitates. Temperature evolution modeling of damage cascades suggests a locally melted region within the damage cascade with substantial temperature gradients and rapid energy dissipation, with a quenching rate much larger than MG's critical cooling rate. Thus, the damage cascade regions do not directly develop nanocrystals. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.