Relation Between Medium-Range Order and Crystallization in Al-Ni Based Metallic Glass

摘要

The structure evolutions of Al83Ni10Ce5Si2, Al83Ni10Ce7, Al85Ni10Ce5, Al87Ni7Nd6 and Al87Ni5Co2Nd6 metallicglasses have been studied in detail. The studies establish a relation between the amount of medium range order (MRO)and crystallization mode. An increased amount of MRO suppresses the precipitation of primary fcc-Al and transforms thecrystallization mode from a primary crystallization (Al87Ni7Nd6) to a eutectic crystallization (Al87Ni5Co2Nd6); while adecreasing amount of MRO promotes the precipitation of primary fcc-Al and transforms the crystallization mode from aeutectic crystallization (Al83Ni10Ce7 and Al85Ni10Ce5) to a primary crystallization (Al83Ni10Ce5Si2).