Continuous W-Cu functional gradient material from pure W to W-Cu layer prepared by a modified sedimentation method

作者：Wei, Bangzheng; Zhou, Rui; Xu, Dang; Chen, Ruizhi; Yu, Xinxi; Chen, Pengqi; Cheng, Jigui^*

来源：Nuclear Engineering and Technology, 2022, 54(12): 4491-4498.

DOI：10.1016/j.net.2022.08.002

• W skeleton
• Cu composites
• Continuously functional graded materials
• Pure W layer
• Porosity distribution
• W

The thermal stress between W plasma-facing material (PFM) and Cu heat sink in fusion reactors can be significantly reduced by using a W-Cu functionally graded material (W-Cu FGM) interlayer. However, there is still considerable stress at the joining interface between W and W-Cu FGM in the W/W-Cu FGM/Cu portions. In this work, we fabricate W skeletons with continuous gradients in porosity by a modified sedimentation method. Sintering densification behavior and pore characteristics of the sedi-mented W skeletons at different sintering temperatures were investigated. After Cu infiltration, the final W-Cu FGM was obtained. The results indicate that the pore size and porosity in the W skeleton decrease gradually with the increase of sintering temperature, but the increase of skeleton sintering temperature does not reduce the gradient range of composition distribution of the final prepared W-Cu FGM. And W-Cu FGM with composition distribution from pure W to W-20.5wt.% Cu layer across the section was successfully obtained. The thickness of the pure W layer is about one-fifth of the whole sample thickness. In addition, the prepared W-Cu FGM has a relative density of 94.5 % and thermal conductivity of 185 W/ (m center dot K). The W-Cu FGM prepared in this work may provide a good solution to alleviate the thermal stress between W PFM and Cu heat sink in the fusion reactors.