Influence of cooling rate on the development of multiple generations of γ′ precipitates in a commercial nickel base superalloy
Influence of cooling rate on the development of multiple generations of γ′ precipitates in a commercial nickel base superalloy
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DOI：
10.1016/j.matchar.2011.06.002
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发表时间：
2011-09-01
影响因子：
4.7
通讯作者：
Banerjee, R.
中科院分区：
文献类型：
--
作者：
Singh, A. R. P.;Nag, S.;Banerjee, R.
通过三维原子探针断层扫描与能量过滤透射电子显微镜研究相结合，对商用镍基高温合金 Rene88DT 连续冷却过程中不同代γ'沉淀物的成分和微观结构演变进行了表征。在单γ相场中固溶后，以非常高的速率连续冷却导致γ'沉淀物的单峰尺寸分布，具有高成核密度和非平衡成分。相反，相对较慢的冷却速率（类似于24℃/分钟）导致γ'沉淀物的多峰尺寸分布，其中较大的第一代初级沉淀物表现出接近平衡成分，而较小规模的二次γ'沉淀物则表现出非平衡成分（Co和Cr过量，Al和Ti贫化）。这些沉淀物附近的γ基质的成分也表现出类似的趋势，与二次沉淀物相比，初级沉淀物附近的成分更接近平衡。 (c) 2011 Elsevier Inc. 保留所有权利。
The compositional and microstructural evolution of different generations of gamma' precipitates during the continuous cooling of a commercial nickel base superalloy, Rene88DT, has been characterized by three dimensional atom probe tomography coupled with energy-filtered transmission electron microscopy studies. After solutionizing in the single gamma phase field, continuous cooling at a very high rate results in a monomodal size distribution of gamma' precipitates with a high nucleation density and non-equilibrium compositions. In contrast, a relatively slower cooling rate (similar to 24 degrees C/min) results in a multi-modal size distribution of gamma' precipitates with he larger first generation primary precipitates exhibiting close to equilibrium composition, along with the smaller scale secondary gamma' precipitates, exhibiting non-equilibrium composition (excess of Co and Cr, depleted in Al and Ti). The composition of the gamma matrix near these precipitates also exhibits similar trends with the composition being closer to equilibrium near the primary precipitates as compared to the secondary precipitates. (c) 2011 Elsevier Inc. All rights reserved.