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将含有0.51％Y和不含Y的两种Fe-Cr-Al合金,在1200℃空气中进行了500小时的氧化实验。用X-射线衍射仪、扫描电镜、电子探针及离子探针对不同氧化时间的试样进行了分析,结果表明,除了初期(约20小时)稍提高Fe-Cr-Al合金氧化速度外,总的说来,钇的添加降低了合金的氧化速度。同时,钇的氧化物分布在以α-Al_2O_3为主的氧化膜中,使得α-Al_2O_3氧化物成为柱状晶,这种构造的氧化膜可经受较大压应力作用,因此在冷热交变过程中氧化膜不易剥落。钇与扩散到基体中的氧优先反应生成Y_2O_3,对阻止合金基体的内氧化及力学性能变坏也起到一定的抑制作用。
Two kinds of Fe-Cr-Al alloys containing 0.51% Y and no Y were subjected to an oxidation test in air at 1200 ° C for 500 hours. The samples with different oxidation time were analyzed by X-ray diffraction, scanning electron microscopy, electron probe and ion probe. The results showed that in addition to slightly increasing the oxidation rate of Fe-Cr-Al alloy in the early stage (about 20 hours) In general, the addition of yttrium reduces the rate of oxidation of the alloy. At the same time, the oxide of yttrium is distributed in the α-Al_2O_3-based oxide film, which makes the α-Al_2O_3 oxide into a columnar crystal. The oxide film of this structure can undergo larger compressive stress, so during the hot and cold alternating process The oxide film is not easy to peel off. Yttrium preferentially reacts with oxygen diffused into the matrix to form Y_2O_3, which also inhibits the internal oxidation of the alloy matrix and deteriorates the mechanical properties.