Gd-Tb二元稀土基非晶合金(Gd-Tb)-Al-Co的非晶形成能力及热稳定性  

Glass-Forming Ability and Thermal Stability of (Gd-Tb)-Al-Co Glass Alloys

作　　者：马丽利[1] 李然[1] 逄淑杰[1] 马朝利[1] 张涛[1] 

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100083

出　　处：《航空材料学报》2008年第4期41-45,共5页Journal of Aeronautical Materials

基　　金：国家自然科学基金资助(50471001和50631010);教育部创新团队计划(IRT0512)的资助

摘　　要：采用铜模铸造法制备Gd-Tb二元稀土基非晶合金(Gd-Tb)-Al-Co。确定(Gd-Tb)-Al-Co合金系的非晶形成区域及非晶形成能力。利用差示扫描量热仪对非晶合金的热稳定性以及合金的熔化和凝固过程进行研究。结果表明,Gd-Tb二元稀土基合金(Gd-Tb)-Al-Co的非晶形成能力远大于单元稀土基合金Gd-Al-Co或Tb-Al-Co的非晶形成能力。在(Gd-Tb)-Al-Co合金中,高非晶形成能力合金位于共晶点附近,非晶形成能力最好的合金(Gd0.5Tb0.5)55Al25Co20位于陡峭的液相面一侧,其临界直径(dc)可以达到5mm。与Gd55Al25Co20和Tb55Al25Co20合金相比,原子尺寸相似的Gd和Tb两个稀土元素降低相应合金的凝固温度,提高液相的稳定性,从而提高合金的非晶形成能力。Glass-forming ability （GFA） in （ Gd-Tb）-Al-Co system were evaluated. The melting and solidification characteristics of corresponding alloys were determined by differential scanning calorimeter. The results of glass formation and thermal analysis reveals that the binary rare-earth based metallic glass alloys, （Gd-Tb）-Al-Co, have higher GFA than single rare earth based alloys, Gd-Al-Co or Tb-Al-Co. The （Gdo.sTbo5 ）55 Al25 Co20 alloy, which has the highest GFA with the critical diameter of 5mm by copper mold casting, is on the steep side of liquidus surface and near the eutectic point. Compared with Gd55Al25Co20 and Tb55Al25Co20, the coexistence of Gd and Tb decreases the solidification temperature of the corresponding alloys, consequently stabilize the liquidus structure and improve the GFA of the resulting alloys.

关 键 词：非晶合金 稀土元素 非晶形成能力 铜模铸造 

分 类 号：TG139[一般工业技术—材料科学与工程]