Experimental characterization and mechanical modeling of creep induced rafting in superalloys
Experimental characterization and mechanical modeling of creep induced rafting in superalloys
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DOI：
10.1016/j.commatsci.2012.05.071
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发表时间：
2012-11
影响因子：
3.3
通讯作者：
B. Fedelich;A. Epishin;T. Link;H. Klingelhöffer;G. Künecke;P. Portella
中科院分区：
文献类型：
--
作者：
B. Fedelich;A. Epishin;T. Link;H. Klingelhöffer;G. Künecke;P. Portella
建立了单晶高温合金高温力学行为的本构模型，包括筏化及其后果。流变应力通过Orowan应力依赖于γ通道宽度。导出了高温应变过程中沟道展宽的演化方程，并用实验进行了标定。其中，漂流被认为是由内部应力松弛驱动的。该模型能够代表机械软化在高应力连续漂流。该模型已被应用于模拟筏在单轴蠕变在几个晶体取向，缺口试样以及在循环加载试样。
A constitutive model has been developed for the high temperature mechanical behavior of single crystal superalloys, including rafting and its consequences. The flow stress depends on the γ channel width via the Orowan stress. An evolution equation for channel widening during high temperature straining has been derived and calibrated with measurements. Therein, rafting is assumed to be driven by the relaxation of internal stresses. The model is able to represent the mechanical softening at high stresses consecutive to rafting. The model has been applied to simulate rafting during uniaxial creep in several crystal orientations, in notched specimens as well as in cyclically loaded specimens.