(西北工业大学 凝固技术国家重点实验室，西安 710072)
摘 要: 通过感应熔炼−喷铸法制备具有非晶/纳米晶复合结构的块体Ti40Zr25Ni8Cu9Be18合金。在与全非晶结构的Ti40Zr25Ni8Cu9Be18合金进行比较的基础上，研究Ti40Zr25Ni8Cu9Be18非晶/纳米晶合金在均匀流变过程中的晶化程度，分析其在连续升温过程中的晶化动力学。结果表明：初始纳米晶的存在不会明显降低非晶/纳米晶合金在过冷液相区流变过程中的结构稳定性；非晶/纳米晶合金的晶化激活能约为233.21 kJ/mol，与非晶合金的晶化激活能大致相同；随着转变分数的增加非晶/纳米晶合金的局部Avrami指数从2变化到0.5，明显低于非晶合金的局部Avrami指数；这表明初始纳米晶并没有明显加速非晶的晶化过程。
关键字: 非晶/纳米晶合金；结构稳定性；均匀变形；晶化动力学
（State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:Ti40Zr25Ni8Cu9Be18 bulk alloy with amorphous/nanocrystalline structure was prepared by electromagnetic induce melting-injection casting. Crystallization of amporhous/nanocrystalline alloy during homogeneous deformation was investigated based on comparing with Ti40Zr25Ni8Cu9Be18 alloy with amorphous structure. The results indicate that the existence of initial nanocrystal doesn’t decrease the structure stability of amporhous/nanocrystalline alloy during rheologic process in supercooled liquid region. Moreover, the activated energy of amporhous/nanocrystalline alloy is 233.21 kJ/mol, and is roughly equal to that of amorphous alloy. Avrami exponent of amporhous/nanocrystalline alloy ranges from 2 to 0.5, which is lower than that of the amorphous alloy. This indicates that the initial nanocrytal wouldn’t promote crystallization.
Key words: amorphous/nanocrystalline alloy; structural stability; homogeneous deformation; crystallization kinetics
