Effect of Mo Addition on Microstructural Characteristics in a Re-containing Single Crystal Superalloy
Effect of Mo Addition on Microstructural Characteristics in a Re-containing Single Crystal Superalloy
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添加Mo对含Re单晶高温合金显微组织特性的影响
DOI：
10.1016/j.jmst.2013.12.019
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发表时间：
2015-02-01
影响因子：
10.9
通讯作者：
Zhang, J.
中科院分区：
文献类型：
--
作者：
Liu, X. G.;Wang, L.;Zhang, J.
研究了 Mo 添加量对含 4 wt% Re 的镍基单晶高温合金显微组织特性的影响。透射电子显微镜下的能量色散谱仪测定的γ/γ'分配比表明，Mo的添加增强了Re、W和Cr在γ基体中的分配，同时降低了基体中Ta的浓度。采用同步辐射衍射测量室温下的gamma/gamma'晶格失配。结果表明，Mo的添加使γ/γ'晶格失配向更大的负值方向改变，并增加了γ晶格的四方畸变。此外，Mo 的添加会导致微观结构不稳定，并改变拓扑密堆积相在 1100 摄氏度暴露过程中的沉淀行为。观察到 m 相不是直接从基体中析出，而是从 σ 相转变而来，σ 相优先作为高 Mo 含量合金中的亚稳态中间体析出。
The effect of Mo addition on microstructural characteristics of a nickel-base single crystal superalloy containing 4 wt% Re was investigated. The gamma/gamma' partitioning ratios determined by energy dispersive spectrometer attached to a transmission electron microscope showed that the addition of Mo enhanced the partitioning of Re, Wand Cr in the gamma matrix while decreased the concentration of Ta in the matrix. Synchrotron radiation diffraction was adopted to measure the gamma/gamma' lattice misfit at room temperature. The results indicated that Mo addition changed the gamma/gamma' lattice misfit towards larger negative as well as increased the tetragonal distortion of the gamma lattice. Additionally, Mo addition led to microstructural instability and altered the precipitation behavior of topologically close-packed phases during 1100 degrees C exposure. Instead of precipitating directly from the matrix, the m phase was observed to be converted from the sigma phase which precipitated preferentially as a metastable intermediate in the alloy with high Mo content.