A modification on Brook formula in calculating the misfit of Ni-based superalloys
A modification on Brook formula in calculating the misfit of Ni-based superalloys
复制标题
计算镍基高温合金失配的Brook公式的修正
DOI：
10.1016/j.matdes.2017.04.020
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发表时间：
2017
影响因子：
8.4
通讯作者：
Liu Yinong
中科院分区：
文献类型：
--
作者：
Long Haibo;Mao Shengcheng;Xiang Sisi;Chen Yanhui;Wei Hua;Zhou Yizhou;Liu JinLai;Liu Yinong
研究了布鲁克公式在基于位错网络结构估算镍基高温合金晶格错配度方面的有效性。从流行的布鲁克公式推导出的经受长时间热暴露的样品的失配值低于通过X射线衍射（XRD）方法确定的失配值，而使用布鲁克公式估计的经受蠕变的样品的失配值大于通过XRD方法确定的失配值。这些差异意味着流行的布鲁克公式在两个方面的无效性：位错网络并不总是成熟到完全弛豫晶格失配，导致低估失配和使用Burgers矢量的全幅值高估失配。为了克服这一问题，提出了一种修正的Brook公式，该公式使用Burgers矢量边缘分量的{100}投影作为有效幅度来消除失配。修正后的Brook公式计算的错配量与XRD法测定的一些镍基高温合金的错配量吻合较好。
The validity of the Brooke formula in estimating the lattice misfit based on dislocation network structure in Ni-based superalloys is investigated. The misfit value of a sample subjected to prolonged thermal exposure as derived from the popular Brooke formula is below that determined by X-ray diffraction (XRD) method, whereas the misfit estimated using the Brooke formula for a sample subjected to creep is greater than that determined by XRD method. These discrepancies imply the invalidity of the popular Brooke formula in two aspects: that a dislocation network is not always mature to fully relax the lattice misfit leading underestimate the misfit and that using the full magnitude of the Burgers vector overestimates the misfit. To overcome this problem, a modified Brook formula using the {100} projection of the edge component of a Burgers vector as the effective magnitude to relieve the misfit is proposed. The misfit derived from the modified Brook formula is in good agreement with the values determined by XRD method for a number of Ni-based superalloys studied.