摘要
采用旋铸急冷工艺在大气环境中制备出了(Ni0.75Fe0.25)78-xNbxSi10B12(x=1,3,5,8,10)合金带材。X射线衍射分析表明x≤8时样品为完全非晶,x=10时不能形成非晶。采用Diamond TG/DTA差热分析仪对非晶薄带的热稳定性及其相关参数Tg,Tx,Tm等进行了测量分析。其中(Ni0.75Fe0.25)73Nb5Si10B12的过冷液相区温度范围ΔTx达50 K,约化玻璃转变温度Trg约为0.617,表明该合金具有较高的非晶形成能力和热稳定性。当Nb含量较少(x≤5)时,Nb的添加提高Tg,Tx并扩大过冷液相区ΔTx,使合金的非晶形成能力和热稳定性增加;Nb含量较多(x≥8)时,Nb的添加诱导富Nb-Ni和Nb-Fe的原子团的形成,这些原子团会成为均质形核的核心,降低合金的非晶形成能力和热稳定性,甚至当x=10时不能够完全形成非晶。
Amorphous ribbon specimens of(Ni_(0.75)Fe_(0.25))_(78-x)Nb_xSi_(10)B_(12)(x=1,3,5,8,10) were prepared by a single roller meltspinning technique in an air atmosphere.The structure of alloy specimens was investigated by XRD in a X′Pert Pro type diffractometer with monochromatic Cu Kα radiation.The result indicates that specimens are fully amorphous except for(x=)10.Glass transition temperature(T_g),crystallization temperature(T_x),melting point temperature(T_m) and different indicators of glass forming ability(GFA) were measured and analyzed by differential thermal analysis(DTA).Undercooled liquid region(ΔT_x) and reduced glass transition temperature(T_(rg)) of(Ni_(0.75)Fe_(0.25))_(73)Nb_5Si_(10)B_(12) amorphous alloy are 50 K,0.617,respectively,which indicate that the alloy has high glass forming ability and thermal stability.When concentration per atom of Nb ≤5%,Nb addition can keep it in amorphous state with ΔT_x extended and T_g,T_x increased to improve its glass forming ability(GFA) and thermal stability.When concentration per atom of Nb≥8%,Nb addition can induce formation of atom groups of Nb-Ni and Nb-Fe which can act as nucleus of nucleation,even(Ni_(0.75)Fe_(0.25))_(68)Nb_(10)Si_(10)B_(12) alloy is not fully amorphous.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2005年第S2期158-162,共5页
Journal of the Chinese Society of Rare Earths
基金
国家863项目(2003AA32X150)资助项目
关键词
非晶形成能力
热稳定性
玻璃转变温度
晶化温度
NI基非晶合金
glass forming ability(GFA)
thermal stability
glass transition temperature
crystallization temperature
Ni-based(amorphous) alloy
