High Heat Flux Components in Fusion Devices

作为未来聚变堆中的一种面向等离子体的材料，钨和高Z材料因其耐腐蚀和低氚库存而受到人们的关注。本工作进行了钨涂层的研制和试制。它们已经用电子束设备进行了热负荷测试。通过在线性等离子体装置中进行辐照，进行了精确的研究。主要研究结果如下：(1)成功地将等离子喷涂技术应用于C/C复合材料。获得的钨层的典型厚度为0.5-1.0 mm。通过对C/C复合材料表面的浇注，解决了热膨胀系数不匹配的问题。到目前为止，最大尺寸为50 mm×60 mm。(2)对镀钨碳和块体钨与无氧铜进行了钎焊试验。5毫米以下的钨装甲在15兆瓦/平方米以下不会被销毁。然而，在钨的上表面发现了微裂纹。需要更详细的分析和进一步的开发来优化钎焊。(3)在钨和碳之间插入了多层Re。已证实在1300℃时，该层起到扩散阻挡的作用。(4)在一定条件下，氢和氦对钨表面的辐照使表面形态发生变化，特别是形成了氢泡和/或氦泡。证实了气泡的形成与氚/氦库存密切相关。今后还需要对这一问题进行更系统的研究。

As, a plasma facing materials in future Fusion reactors, tungsten and high Z materials draw people's attention because its erosion resistance and low tritium inventory. Development and test fabrication of the tungsten coating have been conducted in this work. They have been tested against heat loads with electron beam facilities. Precise investigations have been carried out through irradiation in linear plasma devices. Main results are summarized as follows.(1) Plasma spray coating has been successfully applied to C/C composite. Typical thickness of the tungsten layer achieved is 0.5-1.0 mm. A problem of mismatching in thermal expansion coefficient has been solved by castellation of the surface of the C/C composite. Maximum size was 50 mm x 60 mm up to now.(2) Brazing of the tungsten coated carbon and bulk tungsten to oxygen free copper has been tried. The tungsten armors up to 5 mm were not destroyed up to 15 MW/m2. However, micro-cracks were found the top surface of the tungsten. More detail analyses and further development are needed to optimize the brazing.(3) Multi layered rhenium was inserted between tungsten and carbon. It has been confirmed that the layer acts as a diffusion barrier up to 1300 degree C.(4) Deuterium and helium irradiation to the tungsten surface makes change in surface morphology, in particular, hydrogen and /or helium blisters were formed in some conditions. It is confirmed that the blister formation is strongly correlated with tritium/helium inventory. More systematic studies will be necessary for this problem in future.