Morphological aspects of competitive grain growth during directional solidification of a nickel-base superalloy, CMSX4
Morphological aspects of competitive grain growth during directional solidification of a nickel-base superalloy, CMSX4
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DOI：
10.1023/a:1013753120867
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发表时间：
2002-02-01
影响因子：
4.5
通讯作者：
McLean, M
中科院分区：
文献类型：
--
作者：
D'Souza, N;Ardakani, MG;McLean, M
对镍基高温合金CMSX 4定向双晶进行了淬火定向凝固，试图了解枝晶形态在竞争晶粒生长过程中的作用。对于所考虑的取向差范围（单轴热梯度的初级取向差高达70度），没有证据表明初级取向差枝晶由领先的对准初级上的次级臂过度生长。事实上，据观察，对于这个范围内的取向差，尖端的延迟主要抑制其领先的邻居secondaries的增长。这随后简单地限制了未对准晶体的生长到其原始边界，而不是减小其尺寸，并且被认为是CMSX 4定向凝固期间遇到的稳定轴向取向范围的可能原因。(C)2002 Kluwer Academic Publishers.
Quenched directional solidification of specially oriented bi-crystals of the Ni-base superalloy CMSX4, was carried out in an attempt to understand the role of the dendritic morphology in the process of competitive grain growth. For the range of misorientations considered (primary misoriented by up to 7degrees from the uniaxial thermal gradient), there was no evidence of overgrowth of the primary misoriented dendrite by the secondary arms on the leading aligned primary. In fact, it was observed that for this range of misorientations, the tip of the retarded primary suppresses the growth of secondaries on its leading neighbour. This subsequently simply restricts the growth of the mis-aligned crystal to its original boundary, rather than reducing its size and is suggested as a possible reason for the range of stable axial orientations encountered during directional solidification of CMSX4. (C) 2002 Kluwer Academic Publishers.