Role of oxygen in enhanced fatigue cracking in a PM Ni-based superalloy: Stress assisted grain boundary oxidation or dynamic embrittlment?
Role of oxygen in enhanced fatigue cracking in a PM Ni-based superalloy: Stress assisted grain boundary oxidation or dynamic embrittlment?
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DOI：
10.1016/j.corsci.2018.05.001
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发表时间：
2018-07-15
影响因子：
8.3
通讯作者：
Reed, P. A. S.
中科院分区：
文献类型：
--
作者：
Jiang, R.;Proprentner, D.;Reed, P. A. S.
氧在涡轮机盘用先进镍基高温合金疲劳裂纹强化中的作用已在疲劳裂纹萌生和扩展阶段沿着静态氧化试验进行了评估。研究发现，晶界氧化物侵入具有层状结构。疲劳裂纹的萌生和早期扩展过程主要是由微观组织和变形引起的晶界氧化作用引起的。随着裂纹的扩展，这种贡献所产生的氧化损伤可能会逐渐超过动态脆化过程，直到机械损伤超过氧相关的损伤，导致从晶间裂纹扩展过渡到穿晶裂纹扩展。
The role of oxygen in enhanced fatigue cracking in an advanced Ni-based superalloy for turbine disc application has been evaluated in fatigue crack initiation and propagation stages along with static oxidation tests. It is found that the grain boundary oxide intrusion has a layered structure. The microstructure- and deformation-dependent grain boundary oxidation dominates the fatigue crack initiation and early propagation processes. As the crack propagates, this contribution arising from oxidation damage may gradually be overtaken by dynamic embrittlement processes until the mechanical damage outstrips the oxygen-related damage, resulting in a transition from intergranular to transgranular crack propagation.