(Ni_(0.75)Fe_(0.25))_(78)Si_(10)B_(12)非晶合金非等温晶化动力学效应  

Non-Isothermal Crystallization and Kinetics of (Ni_(0.75)Fe_(0.25))_(78)Si_(10)B_(12) Amorphous Alloy

作　　者：魏恒斗[1] 陈学定[1] 郝雷[1] 张静[1] 

机构地区：[1]兰州理工大学省部共建有色金属新材料国家重点实验室,甘肃兰州730050

出　　处：《稀有金属材料与工程》2006年第11期1720-1724,共5页Rare Metal Materials and Engineering

基　　金：国家"863"项目(2003AA32X150)

摘　　要：采用旋铸急冷工艺在大气环境中制备出了(Ni0.75Fe0.25)78Si10B12非晶合金带材。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Tg,Txi,Tpi并分析其晶化行为,加热速度分别为10K/min,20K/min,30K/min,40K/min。(Ni0.75Fe0.25)78Si10B12非晶合金的Tg,Txi,Tpi均随加热速率的增加而增加,说明其玻璃转变和晶化行为均有动力学效应。分别用Kissinger法和Ozawa法计算该非晶合金的晶化激活能,2种方法的计算结果是一致的。对试样在通高纯氩气保护下,进行等温(695K,715K,745K,765K,保温60min)退火处理,利用XRD分析了非晶合金等温晶化时相转变及组织转变。合金在715K和745K温度退火时,在非晶基体上析出了单一的γ-(Fe,Ni)固溶体,平均晶粒尺寸分别约为10.3nm和18.5nm,765K退火处理后的结晶相为γ-(Fe,Ni),Fe2Si,Ni2Si和Fe3B,平均晶粒尺寸约29.6nm。Amorphous ribbon specimen of （Ni0.75Fe0.25）78Si10B12 was prepared by a single roller melt-spinning technique in air atmosphere. XRD analysis indicates that the specimen was fully amorphous. The thermal stability and crystallization of the amorphous alloy were studied by using the differential thermal analysis （DTA） in argon atmosphere, glass transition temperature （Tg）, crystallization temperature （Txi）, peak temperature （Tpi） were determined, heating rates were 10 K/min, 20 K/min, 30 K/min and 40 K/min, respectively. Tg, Txi, Tpi of the amorphous alloy were found to depend on the heating rate during the continuous heating, suggesting that both glass transition and crystallization have a significant kinetic effect. Apparent crystallization activation energy of （Ni0.75Fe0.25）78Si10B12 amorphous alloy was determined by Kissinger plot method and Ozawa plot method. The amorphous alloy was annealed for 60 rain in an argon atmosphere at different temperatures： 695 K, 715 K, 745 K and 765 K, respectively. The microstructure and phase transformation during crystallization were investigated by using XRD. The results show that upon the specimen being annealed at temperatures 715 K and 745K, a single phase of γ-（Fe, Ni） solid solution with grain size of about 10.3 nm and 18.5 nm respectively will precipitate in the amorphous matrix. The crystallized phases are γ-（Fe, Ni）, Fe2Si, Ni2Si and Fe3B with grain size of about 29.6 nm after annealing at 765 K.

关 键 词：NI基非晶合金 晶化 动力学效应 晶化激活能 相转变 

分 类 号：TG139.8[一般工业技术—材料科学与工程]