Investigation of the microstructure of He+ ion-irradiated TiBe12 and CrBe12 using ex-situ transmission electron microscopy
Investigation of the microstructure of He+ ion-irradiated TiBe12 and CrBe12 using ex-situ transmission electron microscopy
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DOI：
10.1016/j.jnucmat.2023.154812
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发表时间：
2023-11-17
影响因子：
3.1
通讯作者：
Donnelly，Stephen
中科院分区：
文献类型：
--
作者：
Sharp，Jo;Kuksenko，Viacheslav;Donnelly，Stephen
钛和铬铍化物，TiBe 12和CrBe 12，作为核聚变反应堆中氚增殖的中子倍增器是未来潜在的重要材料。根据一个生成氚和氦的→ 2n嬗变反应，铍会经历极高的嬗变，在相关浓度范围内，氚和氦通常会在固体中形成气泡。来自聚变等离子体的中子辐照也将点缺陷引入固体中。这种环境对铍石微观结构的影响很难描述，但对于理解铍石的机械性能及其在聚变反应堆内辐照环境中的演变很重要。这项研究的目的是初步确定和描述的微观结构特征，发生在TiBe 12和CrBe 12时，他和快粒子引起的点缺陷已被引入在聚变反应堆中子增殖相关的温度。在这项研究中，在387和900° C之间的温度范围内用300 kV He注入铍化物样品，用聚焦离子束照射后通过注入表面切片，并使用透射电子显微镜，电子色散X射线光谱（EDX/EDS）和旋进衍射图检查所得的微观结构。TiBe 12和CrBe 12在600° C下都生长出纳米尺度的气泡，在900° C下生长出更大的（100+ nm）气泡，其中一些是小面的。CrBe 12中的一些气泡衬有Cr，其中一些Cr被氧化。TiBe 12发育面状断层，在600° C及以下时为{110}面，在900° C时为{111}面。故障优先与大气泡。在{110}平面上的断层的位移向量与以前的研究发现的两种类型的位移向量R= 1 2< 011>和R= 1 2< 110>有一些共同性，本研究还发现了不匹配的故障，以前发现的类型。CrBe 12也开发了平面故障，但这些外观是完全不同的典型条纹外观的平面堆垛层错和他们的性质仍然未知。氧化物颗粒从制造中发现，在这两个铍，最突出的是在CrBe 12。
Titanium and chromium beryllides, TiBe 12 and CrBe 12, are materials of potential future importance as neutron multipliers for tritium breeding in nuclear fusion reactors. Beryllium experiences extremely high transmutation according to an→ 2n transmutation reaction in which both tritium and helium are produced, which normally form bubbles in solids at the relevant concentration range. Neutron irradiation from the fusion plasma also introduces point defects into solids. The ensuing effect of this environment on the beryllides’ microstructure is poorly characterised, but important for understanding beryllides’ mechanical properties and their evolution in the irradiative environment inside a fusion reactor. This study is intended to initially determine and describe the microstructural features that occur in TiBe 12 and CrBe 12 when He and fast-particle-induced point defects have been introduced at fusion reactor neutron breeder relevant temperatures. In this study, beryllide samples were implanted with 300 kV He at a range of temperatures between 387 and 900° C, sectioned down through the implantation surface with a focused ion beam post-irradiation, and the resulting microstructures examined using transmission electron microscopy, electron-dispersive X-ray spectroscopy (EDX/EDS) and precession diffraction mapping. Nanometre-scale bubbles grew in both TiBe 12 and CrBe 12 at 600° C and larger (100+ nm) bubbles, some faceted, grew at 900° C. Some bubbles in CrBe 12 were lined with Cr, with some of the Cr oxidised. TiBe 12 developed planar faults, on {110} planes at 600° C and below but on to {111} at 900° C. Faults were preferentially associated with large bubbles. The displacement vectors of faults on the {110} planes had some commonality with previous studies that found displacement vectors of the two types R= 1 2< 011> and R= 1 2< 110>; the present study also found faults that did not match either previously found type. CrBe 12 also developed planar faults but the appearance of these was quite different from the typical striped appearance of planar stacking faults and their nature remains unknown. Oxide particles from manufacture were found in both beryllides, most prominently in CrBe 12.