Wide Gap TLP Bonding a Single-Crystal Superalloy: Evolution of the L/S Interface Morphology and Formation of the Isolated Grain Boundaries
Wide Gap TLP Bonding a Single-Crystal Superalloy: Evolution of the L/S Interface Morphology and Formation of the Isolated Grain Boundaries
复制标题
宽间隙 TLP 粘合单晶高温合金：L/S 界面形态的演变和孤立晶界的形成
DOI：
10.1007/s11661-012-1540-7
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发表时间：
2013-04-01
影响因子：
2.8
通讯作者：
Hu, Z. Q.
中科院分区：
文献类型：
--
作者：
Sheng, N. C.;Liu, J. D.;Hu, Z. Q.
研究了300微米宽间隙单晶高温合金瞬间液相(TLP)连接接头的组织演变和连接行为。结果表明，在初始阶段，界面呈胞状生长。随着时间的延长，细胞结构的长度和数量逐渐减少。在最后阶段，界面以平面方式演化。从电子探针(EPMA)分析结果可以看出，B在液/固界面前方的梯度是存在的，并且从初始到最终都变得更加陡峭。界面演化过程中不可避免地会形成孤立晶，等温固化区(ISZ)的生长速率在整个键合过程中都会发生变化，这都与传统的TLP键合模型不同。讨论了孤立晶界的形成机理和凝固速度偏差的原因。此外，还提出了避免ISZ中孤立晶界形成的有效方法。
The microstructural evolution and bonding behavior of transient liquid phase (TLP) bonded joints for single-crystal superalloy samples with a 300-mu m-wide gap have been investigated. The results show that at the initial stage, the interface grows with a cellular structure. With the increase of time, the length and numbers of the cellular structures decrease. At the final stage, the interface evolves with a planar manner. The gradient of B ahead of the liquid/solid interface exists and becomes sharper from the initial to the final analyzed from the electron probe microanalysis (EPMA) results. Inevitably, isolated grain forms during the evolution of the interface and the growth rate of isothermal solidification zone (ISZ) changes through the whole bonding process, and these both deviate from the traditional TLP bonding models. The mechanisms of the formation of the isolated grain boundaries and the reasons for the deviation of the solidification rate are discussed. Also, some effective methods to avoid the formation of isolated grain boundaries in the ISZ are proposed.