Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7969381 | Materials Characterization | 2018 | 6 Pages |
Abstract
Specimens with two different γⲠphase microstructures, named as-heat treated sample with cuboidal γⲠphases and pre-rafted sample with N-type rafted γⲠphases, were compared to investigate the negative influence of the rafted γⲠphases on the creep property in a Ni-based single crystal superalloy with 4% Re addition at 750â¯Â°C and 750â¯MPa condition. The results indicated that the sample with cuboidal γⲠphases exhibited a lower creep rate and a longer rupture life compared to that with rafted γⲠphases. Transmission electron microscope examinations showed that lots of fine γⲠphases impeded first the dislocation movement in the channel of γ matrix in the initial primary creep stage before the cuboidal γⲠphases were cut by stacking faults in as-heat treated sample. However, in pre-rafted sample, some existed superdislocations located in rafted γⲠphases and the mismatch stress release at γ/rafted γⲠinterface resulting from pre-rafted treatment not only decreased the creep resistance of rafted γⲠphases, but also weakened the γ/rafted γⲠinterface pinning effect for dislocation movement. Therefore, the rafted γⲠphases were easily cut by superdislocations and stacking faults resulting in a higher creep rate and a shorter creep life.
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Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Wenchao Yang, QuanZhao Yue, Kaili Cao, Fangyou Chen, Jun Zhang, Ruirong Zhang, Lin Liu,