Ce对Sm-Cu-Ni-Al大块非晶玻璃形成能力及热稳定性的影响

Effect of Ce Addition on the Glass-Forming Ability and Thermal Stability of Sm-Cu-Ni-Al Alloys

用水冷铜模吸铸法制备出名义成分(at%,下同)为Sm55-xCexCu15Ni10Al20(x=0,7,10,13,15,20,25)的合金样品。利用X射线衍射仪确定合金的结构,用示差扫描量热计(DSC)研究合金的玻璃转变、晶化和熔化行为。通过过冷液相区宽度△Tx和约化晶化温度Tx/Tm来表征Sm基大块非晶的玻璃形成能力,用Tg和Tx来表征其热稳定性。结果表明,Ce的加入使Sm基块体金属玻璃热稳定性降低,当Ce含量为10at%时,其玻璃形成能力最强,可以制备出?5mm以上的块体金属玻璃,同时应用Miedema理论和等效电负性差△X讨论了该系列合金的玻璃形成能力。

Sm55-xCexCu15Ni10Al20 （x=0,7,10,13,15,20,25） alloy samples were prepared by casting the melt ingots into a water-cooled copper mould under vacuum. The structure of the alloy samples were analyzed with X-ray diffraction. The glass transition, crystallization and melting behavior of the alloys were investigated by differential scanning calorimetry （DSC）. The supercooled liquid region △Tx and the reduced crystallization temperature Tx/Tm were used to indicate the glass-forming ability. Tg and Tx were used to indicate the thermal stability. As a result, with the addition of Ce the thermal stability of Sm-based were decreased and with a certain amount of Ce it has the best glass-forming ability which can prepare bulk metallic glasses samples of φ5 mm or more. The glass-forming ability of this system were discussed based on electronegativity difference △X and Miedema＇s theory.