Fe73.5Cu1Nb2Si13.5B9Ni1非晶合金的晶化动力学研究

利用差示扫描量热法（DSC）研究了Fe73.5Cu1Nb2Si13.5B9Ni1非晶的纳米晶化动力学。结果表明,晶化过程分为两步完成,晶化初生相为Fe3Si.第一晶化过程的晶化开始温度Tx1、峰值温度Tp1与扫描速度β的对数之间存在着线性关系,分别为：Tx1=736.52＋8.67lnβ和Tp1=743.9＋12.7lnβ.采用Kissinger方法和Ozawa方法计算Fe73.5Cu1Nb2Si13.5B9Ni1非晶合金晶化的表观激活能Eа分别为435.2kJ/mol和441.1 kJ/mol,而成分为Fe73.5Cu1Nb3Si13.5B9的表观激活能大约为410 kJ/mol,表明Ni部分替代Nb后合金的热稳定性提高。第一晶化反应的局域激活能Ec（α）随晶化体积分数α不断下降,Avrami指数表明该非晶合金的晶化为扩散控制的三维晶粒长大过程。探讨了用Ni元素部分替代Finemet合金中Nb元素后非晶合金热稳定性提高的原因。

Crystallization Kinetics of Fe73.5Cu1Nb2Si13.5B9Ni1 Amorphous Alloy

The crystallization kinetics of Fe73.5Cu1Nb2Si13.5B9Ni1 amorphous alloy was investigated by differential scanning calorimetry（DSC） in this paper.The results indicate that the crystallization reactions involve two stages and the primary crystalline phase is Fe3Si.According to the DSC curves at different heating rates,there exist linear relationships between the primary crystallization temperature Tx1 and the peak temperature Tp1 and the heating rate β,i.e.,Tx1=736.52＋8.67lnβ and Tp1=743.9＋12.7lnβ,respectively.The activation energies Eα for primary crystallization are 435.2 kJ/mol and 441.1 kJ/mol calculated by Kissinger and Ozawa methods restectively.However,the activation energy of Fe73.5Cu1Nb3Si13.5B9 amorphous alloy is 410 kJ/mol.The results show that the stability of the Fe73.5Cu1Nb3Si13.5 B9 amorphous alloy is obviously improved due to the partial substitution of Nb by Ni.The local activation energy Ec（α） of the primary crystallization decreases with the crystallized fraction α,and the local Avrami exponents indicate a three dimensional diffusion-controlled grain growth during crystallization.The reasons for improved thermal stability due to partial substitution of Nb by Ni are discussed.