Dislocation cells in additively manufactured metallic alloys characterized by electron backscatter diffraction pattern sharpness
Dislocation cells in additively manufactured metallic alloys characterized by electron backscatter diffraction pattern sharpness
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DOI：
10.1016/j.matchar.2023.112673
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发表时间：
2023-01
影响因子：
4.7
通讯作者：
Fulin Wang;J. Stinville;M. Charpagne;M. Echlin;S. Agnew;T. Pollock;M. Graef;D. Gianola
中科院分区：
文献类型：
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作者：
Fulin Wang;J. Stinville;M. Charpagne;M. Echlin;S. Agnew;T. Pollock;M. Graef;D. Gianola
通过增材制造生产的金属合金通常具有复杂和分级的微观结构，其中晶粒呈现大的取向梯度，沿着具有亚晶粒位错胞。这些多尺度特征协同作用以控制机械行为，但在大面积上以高保真度表征具有挑战性。在这里，我们量化了从几种增材制造的金属合金中获得的电子背散射衍射图案的锐度，以直接在块状材料中的介观尺度上对位错胞进行成像。本文采用的锐度度量反映了来自位错的弹性应变场，并且表现出独特的优点，包括与局部位错密度成比例，对晶粒取向不敏感，并且固有地与取向映射及其相关模态相关。我们的研究结果表明，细胞壁并不总是具有明显的取向差，因此并不总是包含大部分的几何必要的位错，从而进一步加深了我们对增材制造过程中产生的大量位错细胞的起源和影响的理解。
Metallic alloys produced by additive manufacturing often host complex and hierarchical microstructures with grains exhibiting large orientation gradients, along with sub-grain dislocation cells. These multiscale features act in concert to control mechanical behavior, yet are challenging to characterize at high fidelity over large areas. Here, we quantify the sharpness of electron backscatter diffraction patterns obtained from several additively manufactured metallic alloys to directly image the dislocation cells at the mesoscale in bulk materials. The sharpness metric employed herein reflects the elastic strain field from dislocations, and exhibits unique advantages, including being proportional to local dislocation density, insensitive to grain orientation, and inherently correlated with orientation mapping and its related modalities. Our results demonstrate that the cell walls do not always possess appreciable misorientations, and thus do not always contain large fractions of geometrically necessary dislocations, thereby furthering our understanding of the origin and implications of the profuse dislocation cells produced during additive manufacturing.