Effect of dislocation density on improved radiation hardening resistance of nano-structured tungsten-rhenium
Effect of dislocation density on improved radiation hardening resistance of nano-structured tungsten-rhenium
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DOI：
10.1016/j.msea.2014.06.013
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发表时间：
2014-08-12
期刊：
影响因子：
6.4
通讯作者：
Britton, T. B.
中科院分区：
文献类型：
--
作者：
Armstrong, David E. J.;Britton, T. B.
对轧制的5wt%钨合金薄板进行退火处理，得到两种不同的显微组织.当接收时具有高位错密度，使用HR-EBSD测量，以及具有约200 nm厚度的饼状晶粒，并且退火时具有平均晶粒尺寸约90 μ m的等轴晶粒和低位错密度。这两种材料进行离子注入2兆电子伏W +离子的破坏水平为0.07，0.4，1.2和13位移每原子（dpa）。纳米压痕法用于测量硬度的变化后，结晶。虽然辐照诱导硬化被认为是饱和的接收材料在0.4 GPa在0.4 dpa的增加，相对硬度的变化是超过四倍高的退火材料（13 GPa）和饱和不发生13 dpa。辐射响应的这些差异是由于位错网络形式的接收微结构中的损伤的增加的汇。这对于在用于结构应用的复合材料中使用这样的纳米结构化钨片是有利的，因为与块状钨产品相比，它们将具有改善的抗辐射性。同时也表明了在辐射损伤研究中使用理想化微结构的危险性。(C)2014作者由爱思唯尔公司出版
Rolled tungsten 5 wt% rhenium sheet has been annealed to produce two microstructures. As received with a high dislocation density, measured using HR-EBSD, and pancake shaped grains with a thickness of approximate to 200 nm and annealed with equiaxed grains with average grain size of approximate to 90 mu m and low dislocation density. Both materials were ion implanted with 2 MeV W + ions to damage levels of 0.07, 0.4, 1.2 and 13 displacements per atom (dpa). Nanoindentation was used to measure change in hardness after implantations. While irradiation induced hardening is seen to saturate in the as received material at an increase of 0.4 GPa at 0.4 dpa, the relative hardness change is over four time higher in the annealed material (13 GPa) and saturation does not occur by 13 dpa. These differences in radiation response are due to the increased sinks for damage in the as received microstructure in the form of dislocation networks. This is advantageous for use of such nanostructured tungsten sheet in composite materials for structural applications as they will have improved radiation resistance as compared to bulk tungsten products. As well as showing the danger of using idealized microstructures for radiation damage studies. (C) 2014 The Authors. Published by Elsevier B.V.