Fabrication of diamond/W-Cu functionally graded material by microwave sintering

作者：Wei, Chenlong; Cheng, Jigui^*; Zhang, Mei; Zhou, Rui; Wei, Bangzheng; Yu, Xinxi; Luo, Laima; Chen, Pengqi^*

来源：Nuclear Engineering and Technology, 2022, 54(3): 975-983.

DOI：10.1016/j.net.2021.08.035

• W/Cu FGM
• Diamond/W-Cu
• Microwave sintering
• Tungsten-coated diamond
• Thermal conductivity

A four-layered W/Cu functionally graded material (FGM) (W90% + Cu10%/W80% + Cu20%/ W70% + Cu30%/W60% + Cu40%, wt.% fraction) and a four-layered diamond/W-Cu FGM (W90% + Cu10%/ W80% + Cu20%/W70% + Cu30%/W55% + Cu40% + diamond5%, wt.% fraction) were fabricated by microwave sintering. The thermal conductivity and thermal shock resistance of diamond/W-Cu FGM and W-Cu FGM were investigated. The morphologies of the diamond particles and different FGMs were analyzed using AFM, SEM, EDS, and TEM. The results show that a 200 nm rough tungsten coating was formed on the surface of the diamond. The density of the tungsten-coated diamond/W-Cu FGM, obtained by microwave sintering at 1200 degrees C for 30 min, was 94.66%. The thermal conductivity of the fourlayered diamond/W-Cu FGM was 220 W.m(-1).K-1, which is higher than that of the four-layered W/Cu FGM (209 Wm(-1) K-1). This indicates that adding an appropriate amount of tungsten-coated diamond to the high Cu layer W/Cu FGM improves the thermal conductivity of the composite. The diamond/W-Cu FGM sintered at 1200 degrees C for 10 min exhibited better thermal shock resistance than diamond/W-Cu FGM sintered at 1100 degrees C for 10 min.