Isothermal nanocrystallization behavior of bulk metallic glass composites in supercooled liquid region  

作　　者：Xiang-Yun Zhang Zi-Zhou Yuan Xue-Lei Feng Li-Zhi Cui Duan-Xian Li 

机构地区：[1]State Key Laboratory of Advanced Nonferrous Materials,Lanzhou University of Technology, Lanzhou 730050, China

出　　处：《Rare Metals》2017年第11期919-924,共6页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos.51061008 and 50961008)

摘　　要：Bulk metallic glass composites （BMGCs） reinforced by micro- （spherical size of about 10 gin） and nano-sized （20-50 nm） A13Zr crystals were synthesized by copper mold suction casting method. The isothermal crystallization of Cu4oZr44AgsAls BMGCs in the super- cooled liquid region was studied by differential scanning calorimeter （DSC）, X-ray diffractometer （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The mechanisms for nucleation and growth of the crystalline phases precipitated in two-stage crystallization process and the effect of the isothermal treatment on the in situ crystalline phases were discussed. Results show that the BMGCs experience a primary crys- tallization process. Nano-sized A13Zr and Cul0Zr7 phases precipitate from the amorphous matrix successively. Fur- thermore, isothermal annealing has no effect on the pre- existing particles in the as-cast sample, which creates a new method to synthesize BMGCs strengthened by duplex crystalline phases with a large size difference. And the reinforced phase could also be dominated with intention if the as-cast BMGCs preparation and isothermal treatment process can be controlled more accurately.Bulk metallic glass composites （BMGCs） reinforced by micro- （spherical size of about 10 gin） and nano-sized （20-50 nm） A13Zr crystals were synthesized by copper mold suction casting method. The isothermal crystallization of Cu4oZr44AgsAls BMGCs in the super- cooled liquid region was studied by differential scanning calorimeter （DSC）, X-ray diffractometer （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The mechanisms for nucleation and growth of the crystalline phases precipitated in two-stage crystallization process and the effect of the isothermal treatment on the in situ crystalline phases were discussed. Results show that the BMGCs experience a primary crys- tallization process. Nano-sized A13Zr and Cul0Zr7 phases precipitate from the amorphous matrix successively. Fur- thermore, isothermal annealing has no effect on the pre- existing particles in the as-cast sample, which creates a new method to synthesize BMGCs strengthened by duplex crystalline phases with a large size difference. And the reinforced phase could also be dominated with intention if the as-cast BMGCs preparation and isothermal treatment process can be controlled more accurately.

关 键 词：Composite Bulk metallic glasses THERMALSTABILITY Heat treatment CRYSTALLIZATION 

分 类 号：TB33[一般工业技术—材料科学与工程] TG139.8[金属学及工艺—合金]