多元Gd(Tb)-Ni-Al合金系中非晶形成能力的成分依赖性研究

Composition Dependence of Glass-Forming Ability in Gd(Tb)-Ni-Al Alloys

采用水冷铜模吸铸法制备了Gd(Tb)-Ni-Al合金系样品。利用X射线衍射仪(XRD),示差扫描量热仪(DSC)和差热分析仪(DTA)分别检测了合金的结构,玻璃转变,晶化和合金的熔化行为。用γ参数来表征Gd基大块金属玻璃的非晶形成能力。结果表明,多元Gd基合金的非晶形成能力对Tb有较大的依赖性,15%Tb替换Gd57Ni20Al23合金中的Gd元素提高了Gd系合金的非晶形成能力,并应用等效电负性差(Δx)和等效原子半径差(δ)讨论了该系列合金的本征非晶形成能力。

A new series of Gd（Tb）-Ni-Al bulk metallic glasses were prepared by casting the melt ingots in-to a water-cooled copper mould. Their structure was analyzed by X-ray diffraction. The glass transition, crystallization and melting behavior were measured by differential scanning calorimetry （DSC） and differential thermal analysis （DTA）. The γ parameter was used to indicate the glass-forming ability of Gd （Tb）-Ni-Al alloys. The results showed that the glass-forming ability of Gd （Tb）-Ni-Al alloys was dependent on Tb content, and the substitution of 15 % Tb for part of Gd enhanced the glass-forming ability of Gd （Tb）-Ni-Al alloys. The intrinsic glass-forming ability of Gd （Tb）- Ni-Al alloys was discussed by the equivalent electron- egativity difference and the equivalent atomic size parameter.