Creep behavior of Pt-aluminide (PtAl) coated directionally solidified Ni-based superalloy CM-247LC after thermal exposure
Creep behavior of Pt-aluminide (PtAl) coated directionally solidified Ni-based superalloy CM-247LC after thermal exposure
复制标题
DOI：
10.1016/j.msea.2015.06.011
复制
发表时间：
2015-08
期刊：
影响因子：
6.4
通讯作者：
M. Z. Alam;D. Satyanarayana;D. Chatterjee;R. Sarkar;D. Das
中科院分区：
文献类型：
--
作者：
M. Z. Alam;D. Satyanarayana;D. Chatterjee;R. Sarkar;D. Das
在980℃/220℃的压力下，研究了循环氧化对定向凝固镍基高温合金(CM-247LC)铂铝涂层拉伸蠕变性能的影响。蠕变试件在1100℃、750h的空气中进行循环氧化。蠕变速率和蠕变寿命受到热暴露/氧化的不利影响。这些性能的退化程度随着热暴露/氧化时间的增加而增加。这种蠕变行为与涂层中发生的微观组织变化有关，如在B2(NiAl)晶界形成γ膜/包络，在靠近涂层-基材界面的区域形成平行的浮筏，以及氧化过程中基材高温合金中的γ析出粗化。另一方面，蠕变应变不受氧化的显著影响。这可以归因于防止了涂层的存在引起的氧化损伤。
The effect of cyclic oxidation on the tensile creep properties of a Pt-aluminide (PtAl) coated directionally solidified Ni-based superalloy (CM-247LC) has been evaluated at 980 °C/220 MPa. Cyclic oxidation of creep specimens was carried out at 1100 °C in air up to 750 h. Creep rate and creep life were found to be adversely affected by thermal exposure/oxidation. The extent of degradation of these properties increased with increase in the duration of thermal exposure/oxidation. Such creep behavior has been correlated with the microstructural changes taking place in the coating such as formation of γ′ films/envelopes at B2 (NiAl) grain boundaries, formation of parallel rafts in the region close to coating–substrate interface and coarsening of γ′ precipitates in the substrate superalloy during oxidation. The creep strain, on the other hand, was not significantly affected by oxidation. This can be attributed to the prevention of oxidation induced damage by the presence of the coating.