Isothermal Oxidation Behavior of Dysprosium/S-Doped beta-NiAl Alloys at 1200 degrees C
Isothermal Oxidation Behavior of Dysprosium/S-Doped beta-NiAl Alloys at 1200 degrees C
复制标题
镝/S掺杂β-NiAl合金在1200℃下的等温氧化行为
DOI：
10.1016/j.jmst.2013.08.004
复制
发表时间：
2014
影响因子：
10.9
通讯作者：
Xu Huibin
中科院分区：
文献类型：
--
作者：
Wang Lu;Li Dongqing;Chang Jian;Guo Hongbo;Gong Shengkai;Xu Huibin
采用电弧熔炼方法制备了普通纯度β-NiAl合金、S掺杂β-NiAl合金和Dy、S共掺β-NiAl合金，其相应的S含量分别小于20×10−6、33×10−6和22×10−6。研究了合金在 1200 °C 下的等温氧化行为，并通过扫描俄歇显微镜测定了氧化皮 - 合金界面上硫的偏析程度。 S掺杂对θ-向α-Al2O3的相变速率没有显着影响，而Dy的添加则延迟了这一过程。对于掺硫合金，仅在热暴露 2 小时后才出现氧化皮起皱，并且在硫偏析的氧化皮-合金界面处观察到许多大空隙。与此相反，即使在 50 h 等温氧化后，Dy 和 S 共掺杂合金上形成的氧化皮仍然保持平坦，并且在界面处仅存在小空隙，未检测到 S 偏析。
A β-NiAl alloy with normal purity, a S-doped and a Dy and S co-doped β-NiAl alloys were prepared by arc-melting and their corresponding S contents were less than 20 × 10−6, 33 × 10−6and 22 × 10−6, respectively. The isothermal oxidation behavior of the alloys at 1200 °C was investigated and the extent of S segregation at the scale–alloy interface was determined by scanning Auger microscopy. S-doping had no significant effect on the phase transformation rate from θ- to α-Al2O3, while the addition of Dy retarded this process. For the S-doped alloy, scale rumpling occurred only after 2 h thermal exposure and numerous large voids were observed at the scale–alloy interface where S segregated. In contrast to this, the oxide scale formed on the Dy and S co-doped alloy still remained flat even after 50 h isothermal oxidation and only small voids existed at the interface where S segregation was not detected.