(西北工業(yè)大學 凝固技術(shù)國家重點實驗室，西安 710072)
摘 要: 通過感應熔煉−噴鑄法制備具有非晶/納米晶復合結(jié)構(gòu)的塊體Ti40Zr25Ni8Cu9Be18合金。在與全非晶結(jié)構(gòu)的Ti40Zr25Ni8Cu9Be18合金進行比較的基礎(chǔ)上，研究Ti40Zr25Ni8Cu9Be18非晶/納米晶合金在均勻流變過程中的晶化程度，分析其在連續(xù)升溫過程中的晶化動力學。結(jié)果表明：初始納米晶的存在不會明顯降低非晶/納米晶合金在過冷液相區(qū)流變過程中的結(jié)構(gòu)穩(wěn)定性；非晶/納米晶合金的晶化激活能約為233.21 kJ/mol，與非晶合金的晶化激活能大致相同；隨著轉(zhuǎn)變分數(shù)的增加非晶/納米晶合金的局部Avrami指數(shù)從2變化到0.5，明顯低于非晶合金的局部Avrami指數(shù)；這表明初始納米晶并沒有明顯加速非晶的晶化過程。
關(guān)鍵字: 非晶/納米晶合金；結(jié)構(gòu)穩(wěn)定性；均勻變形；晶化動力學
（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
