【摘要】 采用吸铸法制备出直径3mm的Ti40Zr25Ni8Cu9Be18块体非晶合金,并采用X射线衍射(XRD)、差示扫描量热(DSC)和透射电镜(TEM)研究了非晶合金试样的结构,同时,分别采用连续升温晶化方法和等温退火方法研究了该非晶合金的晶化动力学行为和晶化过程中的相转变。结果表明:该非晶合金的结构弛豫和晶化行为均具有显著的动力学特征,且具有较好的热稳定性,其过冷液相区宽度△Tx为54K,一级晶化激活能Ep1为213.04kJ/mol;晶化过程为二级晶化反应,第1阶段晶化对应I相从非晶基体中析出,第2阶段的晶化反应则包括:I相转变为Laves相和Laves相从残余非晶基体中直接析出。更多还原

【Abstract】 Ti-based bulk amorphous alloy with the composition of Ti40Zr25Ni8Cu9Be18 of 3 mm in diameter was fabricated by suction casting method. The microstructure was investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). In addition, the crystallization kinetics behavior and phase transition during crystallization process were studied by non-isothermal crystallization and isothermal anneal heat treatment, respectively. It is showed that the glass transition and crystallization behavior have the typical kinetic characteristics and better thermal stability with a supercooled liquid region ?Tx of 54 K and a phase transformation Ep1 of 213.04 kJ/mol, respectively, for the amorphous alloy. On the other hand, the process of crystallization contained two stages: in the first stage, the crystallization reactions correspond to the precipitation of quasicrystalline phase I in the amorphous matrix; in the second stage, the quasicrystalline phase I was transformed to Laves phase which is directly precipitated from the remaining amorphous matrix.更多还原