含Er高Nb-TiAl基合金的热力学性能  

Thermodynamic properties of high niobium containing TiAl based alloy with erbium

作　　者：宫子琪[1] 陈子勇[1] 柴丽华[1] 聂祚仁[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124

出　　处：《材料热处理学报》2014年第2期205-208,214,共5页Transactions of Materials and Heat Treatment

基　　金：北京市教委高层次人才培养项目(00900054R8002);国家自然科学基金(51301005);北京工业大学博士科研启动基金(009000543113527)

摘　　要：基于Miedema混合焓模型外推出三元合金的热力学性能,利用合金成分的特点计算出了Ti-46Al-8Nb-0.1Er四元合金的各组元间的部分热力学性能,并结合Toop模型得出合金的组元活度及活度系数。结果表明,在此四元系中Er只与Al发生反应,与其它组元之间无反应,生成Er-Al化合物。然而在热力学上,Er2O3比Er-Al化合物更易形成,实验中熔体里不可避免的微量氧的介入,使得合金熔炼过程中Er首先与O结合形成Er2O3颗粒,且此Er2O3相在XRD测试分析证明得到。Er具有净化合金熔体、降低合金基体氧含量和析出强化的作用。Based on the Miedema formation enthalpy model, thermodynamic properties of ternary alloy were calculated. Using the composition characteristics of the alloy, the thermodynamic properties between elements of the quaternary alloy Ti-46A1-8Nb-0.1 Er were studied. Combining Toop model, we derived alloy component activity and activity coefficient. The results show that in this quaternary system Er only reacts with AI generating the Er-A1 compounds while no reaction with the other elements is obseryed. Due to forming Er2 O3 more easily than Er-A1 comounds in thermodynamic, and the existance of trace oxygen is inevitable in the molten alloy, Er combined with O forms Er203 particles, which are observed in experiments by XRD analysis. The Er addition has the effects of purification of the alloy melt, reducing oxygen content of the alloy matrix and the precipitation strengthening.

关 键 词：Ti-Al-Nb-Er合金 Miedema混合焓模型 Toop模型 混合焓 活度系数 

分 类 号：TG146.2[一般工业技术—材料科学与工程]