Studying the Deformation of Tungsten and its Alloys During Mechanical Testing with analysis being performed using EBSD and HR-DIC Methods

该项目着眼于核聚变反应堆中使用的材料，特别是在分流器中，该分流器设计用于承受极高的热通量和高能中子轰击，因此钨是主要的候选材料选择。目前正在进行研究，以了解钨的基本机械性能行为，因为它遭受急性脆性和高脆性到韧性的转变温度。将钨与铼等元素合金化通常是提高其延展性的策略；然而，铼也是一种嬗变产物，在反应器条件下会形成沉淀，加剧合金的脆化。因此，需要探索其他合金选择。本项目旨在研究新型钨合金在聚变反应堆导流器中的应用。这与在微观结构层面上了解拉伸载荷下的行为以及不同合金元素和微观结构对其的影响相结合，并可能扩展到检查辐射或氢同位素载荷的影响。我感兴趣的主要技术是扫描和透射电子显微镜，对高分辨率数字图像相关特别感兴趣，以了解不同合金在近原子尺度上的变形机制。这将有助于将局部微观结构与力学响应联系起来。还将对纯钨进行非原位测试，以获得其机械性能的一套“基线”值。主要目标是获得用于此类应用的理想新型合金。

This project looks at the materials used in a fusion reactor particularly in the divertor which is designed to withstand extremely high heat fluxes and highly energetic neutron bombardment and as such tungsten is the leading candidate material choice. Research is currently being undertaken to understand tungsten's fundamental mechanical property behaviour as it suffers from acute brittleness and a high brittle-to-ductile transition temperature. Alloying tungsten with elements such as rhenium is often the strategy to improve its ductility; however, rhenium is also a transmutation product that can form precipitates under reactor conditions exacerbating the embrittlement of the alloy. Therefore, other alloying options need to be explored. This project is looking at novel tungsten alloys for fusion reactor divertor application. This is coupled with gaining an understanding at the microstructural level the behaviour under tensile loads and how this is impacted by different alloying elements and microstructures with a potential extension of examining either the impacts of radiation or hydrogen isotope loads. The primary techniques that I am interested in are scanning and transmission electron microscopy, with a particular interest in high resolution digital image correlation to understand the deformation mechanisms of the different alloys at the near atomic scales. This will help link the local microstructure to the mechanical response. Ex-situ testing will also be carried out on pure tungsten to acquire a set of "baseline" values for its mechanical properties. The main objective is to obtain the ideal novel alloy to be used in such applications.