摘要
对比研究了Ｎｉ３Ａｌ微晶处理前后在１０００℃氧气中高温氧化的动力学规律。研究结果表明，微晶化处理后，合金氧化速率显著降低，抗氧化性能大大提高；微晶Ｎｉ３Ａｌ氧化动力学规律与Ｗａｇｎｅｒ高温氧化抛物线规律相比，具有明显的负偏差。由于微晶化后形成的氧化膜是微晶，晶界密度极大增加，短路扩散远远大于晶格扩散，根据多维缺陷对氧化动力学的影响规律，并考虑氧化物晶粒长大动力学，推导出微晶氧化动力学服从四次方规律ｘ４＝ｋｐｔ，实验结果与推导结果符合得非常好。
Isothermal oxidation of Ni3Al before and after microcrystallizing at 1 000℃ in O2 has been studied using thermobalance method. It is found that the resistance to oxidation of Ni3Al is greatly improved after microcrystallizing. The oxidation rate of microcrystalline Ni3Al markedly decreases. The oxidation kinetics of microcrystalline Ni3Al is much lower than that of the power law proposed by Wagner. This work focuses on the deviation of kinetics. In the Wagner theory, it was assumed that oxide film grows by lattice diffusion. But the grain of oxide film on microcrystalline Ni3Al is microcrystalline and the density of grain boundary greatly increases. Therefore, short-range diffusion is much more than lattice diffusion. Considering the effects of defects on oxidation kinetics and the grow kinetics of oxide grain, the oxidation kinetics of microcrystalline Ni3Al is derived to obey the forth power law, ie, x4=kpt. The experimental results agree with the values calculated by the formula.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
1998年第3期149-151,共3页
Rare Metal Materials and Engineering
基金
国家自然科学基金
冶金部腐蚀磨蚀与表面科学开放实验室资助
关键词
NI3AL
微晶
高温氧化
腐蚀
高温合金
Ni3Al, microcrystalline, high temperature oxidation, corrosion
