【摘要】 研究了Zr55Al10Ni5Cu30块状非晶合金靠近玻璃转变点等温晶化过程.结果表明:420℃退火5h,出现了尺寸为20 nm左右的晶相,同时,非晶基体也出现了尺寸为1-2 nm分布均匀的团簇状结构;退火10 h,析出的晶相尺寸为20-50nm,所占的体积分数为40％;退火20 h之后,非晶相完全转变为亚稳相,析出的晶相尺寸为50 nm左右,并没有出现明显的长大现象.退火得到的晶相为Cu10Zr7,Zr2Ni及一些未能标定的相,这些相在420℃具有相对的稳定性,没有向稳定相转变.退火后,残余非晶相的热稳定性降低.等温退火过程经历了从非晶相→团簇状结构→亚稳相的转变过程.更多还原

【Abstract】 Isothermal nanocrystallization of Zr55Al10Ni5Cu30 bulk amorphous alloy near the glass transition temperature has been investigated by DSC, XRD and TEM. Nanocrystals with a size of 20 nm precipitated from the amorphous matrix when annealed at 420 "C for 5 h, and homogeneous medium-range order (structure on the 1-2 nm scale) appeared in the amorphous matrix. As annealed at 420 C for 10 h, the nanocrystals have a size of 20-50 nm and a volume fraction of about 40%. The annealing treatment at 420 C for 20 h led to the completion of crystallization of the amorphous structure, but the crystalline phases have a size of 50 nm, justly as the sample treated for 5 h. The crystallization of Zr55Al10Ni5Cu30 bulk amorphous alloy at 420 C is through a process of amorphous-amorphous with medium-range order + metastable phases-metastable phases.更多还原