Abstract
In order to develop material for Divertor of Nucler Fusion Reactor, we investigated bonding method between C-C material (Carbon Fiber/Carbon composite) and three kinds of heat sink materials, the microstructure of the bonding layer, shearing strength, thermal shock resistance temperature and analysis of thermal stress.
C-C material was manufactured with carbon fiber oriented in one direction. Thermal conductivity of C-C is 570 W/m·k along this orientation. For heat sink material, three kinds of material, Cu, Cr-Cu alloy and W-Cu alloy were used.
Results are summarized below ;
(1) As a brazing filler metal for bonding between C-C and copper alloy, ten kinds of brazing filler metals were investigated. As a result 2Ti-AgCu paste filler metal was selected. The brazing filler metal is excellent in wettability and as high shearing strength as a bonding layer.
(2) Shearing strengths of the C-C/copper and copper alloy joints with 2Ti-AgCu paste brazing filler metal decrease in the order of C-C/Cu, C-C/Cr-Cu, C-C/W-Cu. Hardness of the bonding layer decrease in the order of C-C/W-Cu, C-C/Cr-Cu and C-C/Cu. Therefore, the shearing strength of the bonging layer increase with decreasing hardness.
(3) By using a copperplate of 2-5 mm in thickness as a bonding layer between of C-C/Cr-Cu and C-C/W-Cu joints, shearing strength and thermal shock resistance temperature are improved to those of the C-C/Cu joint. Through thrmal stress analysis, the thermal stress relief of the copper plate was confirmed.
