高纯铌的脱氧热力学特性

Thermodynamics of Deoxidation of High Purity Niobium

在 973- 1 473K温度范围内 ,测定了铌与Ca CaO和与Mg MgO共存时铌金属中氧的平衡浓度 .得出并讨论了铌中的氧溶解反应的Gibbs自由能表达式和氧分压 温度 成分 (p t x)关系表达式 .

Starting niobium samples with different oxygen contents were produced by arc melting and electron beam melting respectively.The equilibrium oxygen contents of the niobium metal have been measured in the temperature range of 1173-1473K for Ca CaO Nb and of 973 and1173K for Mg MgO Nb by an inert gas fusion infrared absorption method.The equilibrium oxygen contents in Nb increases with temperature,which is independent of oxygen concentration of the starting Nb samples.Based on the equilibrium oxygen contents,the Gibbs free energy of the oxygen dissolution in niobium metal,as well as the expressions of oxygen pressure temperature component ( p t x ) for theses two equilibrium systems were obtained.The acquired free energy values a less than that reported in the literature.This difference is mainly attributed to the adoption of different standard formation free energy of CaO.