Oxidation behavior of a single-crystal Ni-base superalloy between 900 and 1000 °C in air
Oxidation behavior of a single-crystal Ni-base superalloy between 900 and 1000 °C in air
复制标题
DOI：
10.1016/j.jallcom.2009.10.261
复制
发表时间：
2010-02
影响因子：
6.2
通讯作者：
Chunting Liu;Ji Ma;X. Sun
中科院分区：
文献类型：
--
作者：
Chunting Liu;Ji Ma;X. Sun
采用X射线衍射（XRD）、扫描电子显微镜（SEM）和能谱分析（EDS）研究了单晶镍基高温合金DD 32在900和1000°C空气中的氧化行为。在900和1000°C下，氧化动力学中出现两个氧化步骤。第一个是由NiO的生长和第二Al 2 O3的生长控制，直到一个连续的Al 2 O3层下形成的先前生长的NiO层后的临界时间。在900 ~ 1000 °C的氧化过程中，凝固过程中产生的偏析导致化学成分的变化，导致在枝晶和枝晶间区域形成不同种类的氧化皮。在900 ~ 1000°C温度范围内形成的氧化膜结构复杂，由三层组成：外层为柱状NiO层，含有少量CoO;中间层主要由W20 O 58、CrTaO 4和少量尖晶石NiCr 2 O 4、NiAl 2 O 4和CoAl 2 O 4组成;
The oxidation behavior of a single-crystal Ni-base superalloy DD32 was studied in air at 900 and 1000°C and analyzed by X-ray diffraction (XRD), scanning electron microscopy, combined with energy-dispersive X-ray spectroscopy (SEM/EDS). At 900 and 1000°C, two oxidation steps appear in the oxidation kinetics. The first one is controlled by NiO growth and the second by Al2O3growth until a continuous Al2O3layer formed under the previously grown NiO layer after a critical time. The variations in the chemical composition due to segregations, which resulted from the solidification process, led to the formation of different kinds of oxide scale on the dendritic and interdendritic area during oxidation between 900 and 1000 °C. The scales formed between 900 and 1000°C were complicated, and consisted of three layers: an outer columnar NiO layer with a small amount of CoO, an intermediate layer mainly composed of W20O58, CrTaO4, a small amount of spinels NiCr2O4, NiAl2O4and CoAl2O4, an inner continuous layer of α-Al2O3.