Thermal grain boundary grooving with anisotropic surface free energies
Thermal grain boundary grooving with anisotropic surface free energies
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DOI：
10.1016/j.actamat.2003.08.033
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发表时间：
2004-01
期刊：
影响因子：
9.4
通讯作者：
W. Zhang;P. Sachenko;I. Gladwell
中科院分区：
文献类型：
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作者：
W. Zhang;P. Sachenko;I. Gladwell
我们研究了各向异性的表面自由能的影响下，表面扩散的热晶界开槽轮廓建模，模拟和实验与钨。基于Herring的[W.E.金斯顿（编辑），The Physics of Powder Metallurgy，McGraw-Hill，纽约，1951，p.143]模型表明，当各向异性较弱时，凹槽轮廓在演化中是自相似的，但通常与各向同性材料特性下形成的凹槽轮廓不成比例。切槽动力学服从指数为1/4的幂律。当各向异性是临界表面刻面发生。而且，当它是严重的方面粗糙的演变。我们展示了不同程度的各向异性下的槽的轮廓的演变。我们在实验中观察到，{110}和{111}取向的晶粒在退火过程中形成小的表面刻面，如在严重各向异性的情况下，而那些没有晶体取向的晶粒倾斜约45°到样品表面不。
We study the effect of anisotropic surface free energy on thermal grain boundary grooving profiles under surface diffusion using modeling, simulation and experiments with tungsten. Based on Herring’s [W.E. Kingston (Ed.), The Physics of Powder Metallurgy, McGraw-Hill, New York, 1951, p. 143] model we show that when the anisotropy is mild, the groove profiles are self-similar in the evolution but are often not in proportion to those developed under isotropic material properties. The grooving kinetics obey power laws with the exponent 1/4. When the anisotropy is critical surface faceting occurs. And, when it is severe the facets coarsen in the evolution. We exhibit the groove profiles in evolution under different degrees of anisotropy. We observe in the experiments that the {110} and {111} oriented grains develop small surface facets during annealing, as in the severely anisotropic cases, whilst those grains without crystalline orientation tilted at about 45° to the sample surface do not.