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研究了不同稀土含量铁铬铝合金,在高温下晶粒长大及界面结构。结果表明:在1200℃以上高温,稀土组元(以La为主)对抑制合金的晶界长大有一定效果,La_2O_3可作为TiN相析出的形核中心,细小TiN质点可在晶界上出现,阻碍晶界迁移;在变温过程中,La向界而扩散,在晶界以La_2O_3形式出现,同时稀土加速氧穿过氧化膜向基体中渗透,导致Al_2O_3及La_2O_3在基体中形成。
The iron-chromium-aluminum alloy with different rare earth contents, grain growth and interfacial structure at high temperature were studied. The results show that rare earth elements (mainly La) have some effect on inhibiting the growth of the grain boundaries at temperatures above 1200 ℃. La_2O_3 can be used as the nucleation center for TiN phase precipitation. Small TiN particles can appear on the grain boundaries , Which hinders the grain boundary migration. In the process of temperature change, La diffuses to the boundary and La_2O_3 forms in the grain boundary. At the same time, rare earth accelerates the penetration of oxygen into the matrix through the oxide film, resulting in the formation of Al_2O_3 and La_2O_3 in the matrix.