Abstract:

The recrystallized graphites were prepared with calcined coke filler, coal-tar pitch binder and additives of B₄C、Si、Ti by the hot-pressing in order to investigate the thermo-mechanical properties and microstructure of the recrystallized graphites. Radiation damages of the recrystallized graphites by ion bombardment in HT-7 fusion environment were also studied. The experimental results showed that the recrystallized graphites doped 10%B₄C exhibited higher bending strength, up to 104Mpa, but lower thermal conductivity; on the contrary, the recrystallized graphites doped Si and Ti exhibited higher thermal conductivity but lower bending strength. Compared with pure graphite, the erosion-resistant of the recrystallized graphites was improved obviously. The thickness of the gradient SiC coating of BSTDG was thinned from 40～50μm to 5μm, and the coating flaked off partially after irradiation in HT-7 tokamak.

Key words: Doped graphite, Plasma facing materials, Chemical erosion, SiC gradient coating

摘要：

用煅烧石油焦作填料、煤沥青作粘结剂和B₄C、Si、Ti作添加剂，利用热压工艺制备了系列重结晶掺杂石墨，并通过化学气相反应法在掺杂石墨表面沉积了有梯度的SiC涂层。对掺杂石墨的热力学性能、微观结构及在HT-7装置的聚变环境中的行为进行了考察。结果表明：与纯石墨材料相比，掺杂了10%的B₄C的重结晶石墨力学性能得到明显的改善，抗弯强度达104Mpa，但导热性能较差；掺杂了Si、Ti的重结晶石墨的热导率高，达314W•m^-1•K^-1，但力学性能较差；掺杂了BSTDG的石墨在聚变环境中的抗等离子体辐照能力明显提高；在HT-7装置中经过一轮实验的辐照后，SiC涂层厚度因等离子体的刻蚀由初期的40～50μm下降至5μm左右，且局部区域涂层剥落。

关键词: 掺杂石墨, 等离子体面壁材料, 化学腐蚀, SiC梯度涂层