Ti_2AlNb合金不同温度下的高温氧化行为

High temperature oxidation behaviors of Ti_2AlNb alloy at different temperatures

研究了Ti2AlNb合金在不同温度下的高温氧化行为。采用连续氧化增重的方法计算了合金氧化动力学规律;用XRD、SEM、EDS等手段研究氧化后的表面相结构和表面、截面形貌以及元素分布。结果表明,Ti2AlNb合金在650℃和750℃下的连续氧化动力学曲线近似符合抛物线规律,而在850℃时符合直线规律。氧化层分层现象明显,且都未形成连续致密的Al2O3保护层。氧化产物主要为Ti O2,少量的Al2O3、Nb2O5,以及微量的AlNbO4、Nb2Ti O7、AlNb2。氧化温度越高,分层越明显,富氧层越厚,危害性氧化物越多。

High temperature oxidation behaviors of Ti2AlNb alloy at different temperatures were studied. The oxidation kinetics of the alloy was calculated by the method of thermo gravimetric analysis. Oxide layer morphology and element distribution of the alloy were studied by means of XRD,SEM and EDS. The results show that the oxidation kinetics curves of the Ti2AlNb alloy are accord with parabolic law at650 ℃ and 750 ℃,but at 850 ℃ it's in conformity with the linear rule. The oxide layers delaminate obviously and don't form continuous and compact Al2O3 film. The oxidation products are mainly consist of Ti O2 and a small quantity of Al2O3,Nb2O5,traces of AlNbO4,Nb2TiO7and AlNb2. The higher oxidation temperature is,the thicker the layers are,and the more harmful oxidation products consist.