Plastic deformation mechanisms in a crept L12 hardened Co-base superalloy
Plastic deformation mechanisms in a crept L12 hardened Co-base superalloy
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DOI：
10.1016/j.msea.2013.02.007
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发表时间：
2013-06
期刊：
影响因子：
6.4
通讯作者：
F. Pyczak;A. Bauer;M. Göken;S. Neumeier;U. Lorenz;M. Oehring;N. Schell;A. Schreyer;A. Stark-A.-Star
中科院分区：
文献类型：
--
作者：
F. Pyczak;A. Bauer;M. Göken;S. Neumeier;U. Lorenz;M. Oehring;N. Schell;A. Schreyer;A. Stark-A.-Star
利用透射电镜研究了L12硬化钴基高温合金的蠕变塑性变形机制。变形主要发生在钴固溶体基体中，变形机制为普通a/2 <$101 <${111}位错滑移和γ′相垂直于外压应力轴的筏形运动。位错结构是γ/γ′界面位错网络发展的早期阶段。此外，γ′沉淀物被部分位错剪切，产生层错，层错有时延伸到基体通道和相邻的γ′沉淀物上。由于在蠕变温度下的正晶格失配，与平行通道相比，垂直于压缩外部应力轴的基质通道中的位错活动不太明显。
Plastic deformation mechanisms in a crept L12hardened Co-base superalloy are investigated by transmission electron microscopy. The deformation happens mainly in the cobalt solid solution matrix by slip of ordinary a/2〈101〉{111} dislocations and rafting of the γ′ precipitates perpendicular to the external compressive stress axis is observed. Dislocation structures are early stages of the development of γ/γ′ interfacial dislocation networks. Furthermore, γ′ precipitates are sheared by partial dislocations generating stacking faults which sometimes extend over matrix channels and neighbouring γ′ precipitates. Due to the positive lattice mismatch at creep temperature the dislocation activity in matrix channels perpendicular to the compressive external stress axis is less pronounced compared to parallel channels.