Direct evaluation of grain boundary hydrogen embrittlement: A micro-mechanical approach
Direct evaluation of grain boundary hydrogen embrittlement: A micro-mechanical approach
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DOI：
10.1016/j.msea.2016.03.035
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发表时间：
2016-04
期刊：
影响因子：
6.4
通讯作者：
Y. Takahashi;H. Kondo;R. Asano;S. Arai;Kimitaka Higuchi;Yuta Yamamoto;S. Muto;N. Tanaka
中科院分区：
文献类型：
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作者：
Y. Takahashi;H. Kondo;R. Asano;S. Arai;Kimitaka Higuchi;Yuta Yamamoto;S. Muto;N. Tanaka
为了直接研究多晶材料的晶界氢脆，提出了一种新的微观力学测试方法。结合现场取样技术和高压环境透射电子显微镜（HV ETEM），对镍铝化物（Ni 3Al）多晶中相同GB制备的微悬臂梁试样在有/无氢气（H2）环境中的断裂性能进行了严格比较。对于随机取向的晶界，在含氢环境中观察到脆性断裂形核伴随着塑性变形，除了具有小的取向差异。没有观察到GB断裂的连贯的B_3边界。氢增强脱粘（HEDE）机制的相似性即使对于亚微米尺度的样品也是有效的。
In order to directly investigate the grain boundary (GB) hydrogen embrittlement in polycrystalline materials, a novel micro-mechanical testing method was developed. By combining a site-specific sampling technique and a high-voltage environmental transmission electron microscope (HV ETEM), the fracture property of micro-cantilever specimens fabricated from thesameGB in a nickel-aluminide (Ni3Al) polycrystal was critically compared in environments with/without hydrogen (H2) gas. For randomly oriented GBs, brittle fracture nucleation accompanied by plastic deformation was observed in a H2-containing environment except for ones with small orientation difference. No GB fracture was observed for coherent Σ3 boundaries. It also appeared that the similitude of the hydrogen-enhanced decohesion (HEDE) mechanism was still valid even for the submicron-scale specimens.