Atom probe tomography analysis of the distribution of rhenium in nickel alloys
Atom probe tomography analysis of the distribution of rhenium in nickel alloys
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DOI：
10.1016/j.actamat.2009.10.008
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发表时间：
2010-02
期刊：
影响因子：
9.4
通讯作者：
A. Mottura;N. Warnken;Michael K. Miller;M. Finnis;R. Reed
中科院分区：
文献类型：
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作者：
A. Mottura;N. Warnken;Michael K. Miller;M. Finnis;R. Reed
用原子探针层析术(APT)研究了Re在二元Ni-Re合金和镍基单晶CMSX-4高温合金中的分布。发展了一个专门建立的算法来量化溶质团簇的尺寸分布，并将其应用于APT数据集，以批判在这些系统中Re容易形成团簇的假设。没有发现证据表明Re在随机波动所预期的水平以上形成溶质团簇。在CMSX-4中，Re在靠近基质/沉淀物(γ/γ‘)相界的基质相中被检测到。相场模拟表明，这是由于γ/γ界面在冷却过程中从工作温度向外迁移所致。因此，Re的聚集和界面富集物都不是Re合金化带来的高温力学性能提高的原因。
Atom probe tomography (APT) is used to characterise the distributions of rhenium in a binary Ni–Re alloy and the nickel-based single-crystal CMSX-4 superalloy. A purpose-built algorithm is developed to quantify the size distribution of solute clusters, and applied to the APT datasets to critique the hypothesis that rhenium is prone to the formation of clusters in these systems. No evidence is found to indicate that rhenium forms solute clusters above the level expected from random fluctuations. In CMSX-4, enrichment of Re is detected in the matrix phase close to the matrix/precipitate (γ/γ′) phase boundaries. Phase field modelling indicates that this is due to the migration of the γ/γ′ interface during cooling from the temperature of operation. Thus, neither clustering of rhenium nor interface enrichments can be the cause of the enhancement in high temperature mechanical properties conferred by rhenium alloying.