一种含Ti镍基合金在950℃的恒温氧化行为

摘要

The oxidation behaviour of the superalloy at 950 ℃ in air has been investigated by means of measuring the kinetics curves of the oxidation and analysis using SEM, XRD and ED AX. Results show that the initial oxidation rate is large, and the rate of mass gaining decreases gradually with time extending, the oxidation kinetics obeys parabolic law. A small a-mount of oxide scale spallation happens in the course of oxidation at 950℃. After oxidized at 950 ℃, three oxide layers form on the alloy including the outer consists of TiO2, middle consists of NiCr2O4, CrTiO3 and NiAl2O4 phases, and internal oxidizing layers is identified as A12O3 phase.%用热重分析法测定了氧化动力学曲线,并采用XRD和SEM/EDAX等手段,研究了一种镍基合金950℃的高温氧化行为.结果表明,在950℃氧化初期,合金的氧化质量增重较快,随着氧化时间延长,氧化质量增加的速率逐渐降低,氧化动力学曲线符合抛物线规律,氧化膜出现少量剥落.合金表面氧化膜由三层组成,外氧化层为TiO2,中间层氧化物为Cr2O3 、NiCr2O4、CrTiO3和NiAl2O4,内氧化层氧化物为Al2O3.