(Ni_(0.75)Fe_(0.25))_(70)Zr_8Si_(10)B_(12)非晶合金非等温晶化行为研究

Non-Isothermal Crystallization Kinetics of (Ni_(0.75)Fe_(0.25))_(70)Zr_8Si_(10)B_(12) Amorphous Alloy

采用旋铸急冷工艺在真空条件下制备出(Ni0.75Fe0.25)70Zr8Si10B12合金条带。经X射线衍射(XRD)分析表明样品为完全非晶。用DiamondTG/DTA差热分析仪在高纯氩气保护下测量了非晶薄带的热稳定性参数玻璃转变温度Tg、晶化起始温度Txi、晶化峰值温度Tpi。选用不同的升温速率,即10,20,30,40 K.min-1研究其晶化行为。结果表明,随升温速度的增大,特征温度Tg,Txi,Tpi均向高温区移动,其玻璃转变与晶化行为都与加热速率有关,均具有动力学效应。应用Kissinger法与Ozawa法研究了(Ni0.75Fe0.25)70Zr8Si10B12非晶合金的非等温晶化动力学行为。计算了不同特征温度下的激活能E、频率因子,用Kissinger法和Ozawa法计算的激活能结果是一致的。

Amorphous ribbon specimen of （Ni0.75Fe0.25）70Zr8Si10B12 was prepared by a single roller meltspinning technique in vacuum. XRD analysis indicates that the specimen is fully amorphous. The thermal stability and crystallization of the amorphous alloy was studied by using the differential thermal analysis （DTA） in an argon atmosphere, and glass transition temperature （Tg）, crystallization temperatures （Txi）, peak temperatures （Tpi） were determined, heating rates were 10, 20, 30 and 40 K·min^-1, respectively. Results show that glass transition temperature （ Tg）, crystallization temperatures （ Txi）, peak temperatures （Tpi） of the amorphous alloy all shift to the high temperature zone with the heating rate increasing, suggest that both glass transition and crystallization depend on the heating rate, and have a significant kinetic effect. Non-isothermal crystallization and kinetics of （Ni0.75 Fe0.25）70Zr8Si10B12 amorphous alloys were analyzed by using Kissinger plot method and Ozawa plot method. Crystallization activation energy of Tg, Txi, Tpi and frequency factor were calculated. Consistent crystallization activation energy of （ Ni0.75 Fe0.25 ）70 Zr8Si10B12 amorphous alloy was determined by Kissinger plot method and Ozawa plot method.