Deformation and fracture of carbonaceous materials using in situ micro-mechanical testing
Deformation and fracture of carbonaceous materials using in situ micro-mechanical testing
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DOI：
10.1016/j.carbon.2016.11.084
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发表时间：
2017-04-01
期刊：
影响因子：
10.9
通讯作者：
Flewitt, Peter E. J.
中科院分区：
文献类型：
--
作者：
Liu, Dong;Flewitt, Peter E. J.
采用一种新型的原位微悬臂梁弯曲方法研究了玻璃碳和另外三种多孔石墨材料的局部力学性能。玻璃碳被用于验证的微观力学测量。过滤石墨是一种单相材料，孔隙率约为52体积%。Gilsocarbon石墨是一种核级石墨，目前用于英国的先进气冷反应堆，填料颗粒和基质中的孔隙率约为20 vol%; Pile Grade-A石墨（PGA）是从Magnox反应堆堆芯内的燃料砖中提取的，由于中子辐照和CO2辐射氧化，重量损失15%。在微观尺度下获得的“真实”材料性能被发现是高得多的值比那些在宏观尺度上测量，由于不同的故障控制机制。特别是对于PGA石墨，微观机械测试允许单独测量填料颗粒和基质的机械性能。填料颗粒表现出更高的刚度和弯曲强度与基体相比，这表明不同的影响，中子辐照这两个组成部分。它表明，在这里，具有各种复杂的微观结构，甚至中子辐照后的碳质材料的局部机械性能可以成功地“评估。(C)2016爱思唯尔有限公司版权所有
The local mechanical properties of vitreous carbon and another three porous graphite materials have been investigated using a novel in situ micro-cantilever bending approach. Vitreous carbon is used for validation of the micro-mechanical measurements. Filter graphite is a single phase material with similar to 52 vol % porosity. Gilsocarbon graphite is a nuclear-grade graphite that is currently used in the advanced gascooled reactors in the UK with similar to 20 vol% porosity in the filler particles and matrix; Pile Grade-A graphite (PGA) was extracted from a fuel brick within a Magnox reactor core with 15% weight loss due to neutron irradiation and CO2 radiolytic oxidation. The 'true' material properties obtained at micro-scale are found to be of much higher value than those measured at the macro-scale due to different failure controlling mechanisms. In particular for the PGA graphite, the micro-mechanical tests allowed the mechanical properties of the filler particles and matrix to be measured separately. The filler particles showed a higher stiffness and flexural strength compared with the matrix indicating the different influence of neutron irradiation on these two constituents. It is demonstrated here that the local mechanical properties of carbonaceous materials with various complex microstructures and even following neutron irradiation can be successfully" evaluated. (C) 2016 Elsevier Ltd. All rights reserved.