Development of tungsten diamond composites for nuclear fusion applications

该项目将重点分析和开发用于聚变应用的钨金刚石复合材料。技术背景：titer导流器等离子体面组件（pfc）的设计可承受10 MW m-2的稳态表面加热。相比之下，再入时航天器隔热罩的数值约为1 MW m-2，弧焊机的数值为10-80 MW m-2，低温冷却火箭发动机喷嘴的数值为50-150 MW m-2。在过去的25年里，核聚变的进展很大程度上依赖于在高热流区域使用细颗粒石墨和碳纤维复合材料，在这些区域，碳技术是从裂变和航空航天工业中改编而来的。最近，碳表面已经增强了高性能钨薄膜（10-200微米），以增加抗侵蚀性。在类似的时间框架内，CVD的钻石已经变得很容易获得。从2007年到2010年，UKAEA领导的一个研究项目包括：(i)一个5毫米厚的硼掺杂板原型，暴露在高热流电子束测试中，以及（ii）在几个聚变装置中暴露在等离子体中的薄膜。CVD金刚石之所以令人感兴趣，是因为与所有其他材料相比，金刚石具有许多相关特性，通常是同类中最好的：-室温下的各向异性导热系数比铜高5倍，-非常低的热膨胀，-以上结合使金刚石具有无与伦比的抗热震性，-升华而不是熔化，-在气体环境中与氢的化学反应性低，-与包括钨在内的许多金属形成牢固的碳化物化学键，-高拉伸强度，并且具有良好的抗中子辐射损伤能力。目的研制和分析钨金刚石复合材料。这将有助于多层复合钨金刚石材料的发展，以便：a)降低化学反应性，b)增加物理溅射的抗侵蚀性，c)在高温下边际提高延展性，以及)准自我修复，因为如果表面膜丢失，金刚石会侵蚀直到形成新的钨层。该项目将致力于开发钨金刚石复合材料和潜在的多层复合材料，并在聚变相关条件下进行测试。实验分析技术将用于评估新材料的质量。

This project will focus on the analysis and development of tungsten diamond composites for fusion applicationsTechnical ContextITER divertor plasma facing components (PFCs) are engineered to withstand 10 MW m-2 of steady-state surface heating. For comparison, the value is approximately 1 MW m-2 for a spacecraft heat shield during re-entry, 10-80 MW m-2 for an arc welder, and 50-150 MW m-2 for a cryogenically cooled rocket engine nozzle. For the last 25 years, progress in fusion has largely relied on the use of fine grain graphite and carbon fiber composites in the high heat-flux regions, where the carbon technology was adapted from the fission and aerospace industries. More recently, the carbon surface has been enhanced with high performance tungsten thin films (10-200 microns) in order to increase erosion resistance. Over a similar timeframe, diamond from CVD has become readily available. A UKAEA led research programme from 2007-2010 included: (i) a 5 mm thick boron-doped plate prototype exposed to high heat-flux electron beam testing, and (ii) thin films exposed to plasma in several fusion devices.CVD diamond is of interest because diamond has many relevant properties that are often best-in-class compared to all other materials: -isotropic thermal conductivity 5 times higher than copper at room temperature,-very low thermal expansion,-the above combine to give diamond unparalleled thermal shock resistance,-sublimates instead of melting,-low chemical reactivity with hydrogen in a gas environment,-forms strong carbide chemical bonds with many metals, including tungsten,-high tensile strength, and-good resistance to neutron radiation damage.Objective The goal is to work on developing and analysing tungsten diamond composites. This will contribute to the development of a multi layered composite tungsten diamond material in order to:a) reduce chemical reactivity, b) increase the erosion resistance to physical sputtering,c) marginal improved ductility at elevated temperatures, andd) quasi-self-repairing, since the diamond erodes until a new tungsten layer if the surface film is lost.This project will work on developing tungsten diamond composites and potentially a multi-layer composite and test them under fusion relevant conditions. Experimental analysis techniques will be used to assess the quality of the novel material.