Isothermal nanocrystallization behavior of bulk metallic glass composites in supercooled liquid region
Isothermal nanocrystallization behavior of bulk metallic glass composites in supercooled liquid region
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DOI：
10.1007/s12598-014-0358-4
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发表时间：
2017-11
期刊：
影响因子：
8.8
通讯作者：
Xiangyun Zhang;Z. Yuan;Xuebin Feng;L. Cui;Duan-Xian Li
中科院分区：
文献类型：
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作者：
Xiangyun Zhang;Z. Yuan;Xuebin Feng;L. Cui;Duan-Xian Li
采用铜模吸铸法制备了微米级（球形尺寸约10 μm）和纳米级（20-50 nm）Al 3 Zr晶体增强块体金属玻璃复合材料（BMGCs）。利用差示扫描量热仪（DSC）、X射线衍射仪（XRD）、扫描电镜（SEM）和透射电镜（TEM）研究了Cu 40 Zr 44 Ag 8 Al 8 BMGCs在过冷液相区的等温结晶过程。讨论了两阶段结晶过程中析出的晶相的形核和长大机制以及等温处理对原位晶相的影响。结果表明，BMGCs经历了一次晶化过程。纳米Al 3 Zr和Cu 10 Zr 7相依次从非晶基体中析出。此外，等温退火对铸态样品中原有的颗粒没有影响，这为制备大尺寸差双晶相强化的BMGCs提供了一种新的方法。如果能够更精确地控制铸态BMGCs的制备和等温处理工艺，还可以有目的地控制增强相。
Bulk metallic glass composites (BMGCs) reinforced by micro- (spherical size of about 10 μm) and nano-sized (20–50 nm) Al3Zr crystals were synthesized by copper mold suction casting method. The isothermal crystallization of Cu40Zr44Ag8Al8BMGCs in the supercooled 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 crystallization process. Nano-sized Al3Zr and Cu10Zr7phases precipitate from the amorphous matrix successively. Furthermore, 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.