Unveiling different oxide scales in a compositionally complex polycrystalline CoNi-base superalloy
Unveiling different oxide scales in a compositionally complex polycrystalline CoNi-base superalloy
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DOI：
10.1016/j.jallcom.2023.169558
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发表时间：
2023-03
影响因子：
6.2
通讯作者：
Longjun Li;Li Wang;Zhida Liang;Junyang He;M. Song
中科院分区：
文献类型：
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作者：
Longjun Li;Li Wang;Zhida Liang;Junyang He;M. Song
对成分复杂的多晶 CoNi 基高温合金在 900 ℃ 氧化后，在样品表面以及沿晶界形成多种类型的氧化皮进行了详细研究。复杂的多层氧化皮在稳态条件下形成（氧化时间直至 24 小时）。稳态氧化皮分解（氧化 48 小时）后，会出现不同类型的氧化皮。此外，还发现氧化可以沿着晶界逐渐延伸到样品内部。当晶界从试样表面延伸到内部时，沿晶界形成的氧化皮逐渐形成，这是由于平衡氧分压差异导致元素选择性氧化造成的。据认为，局部微观结构和氧浓度等因素极大地影响了所研究合金的氧化皮的形成和配置。
The formation of multiple types of oxide scales on the specimen surface as well as along the grain boundaries was investigated in detail in a compositionally complex polycrystalline CoNi-base superalloy after oxidation at 900 ℃. The complex multilayered oxide scale forms under steady-state condition (oxidation time till 24 h). After the breakdown of the steady-state oxide scale (oxidation for 48 h), different types of oxide scales occur. Additionally, it is found that oxidation can gradually extend into the specimen interior along the grain boundaries. The oxide scale formed along the grain boundaries evolves when the boundaries extend from specimen surface into interior, which is caused by the selective oxidation of elements by the differences in equilibrium oxygen partial pressures. It is proposed that factors, i.e., local microstructure and oxygen concentration, greatly influence the formation and configuration of the oxide scales of the investigated alloy.