Joining of A1N and graphite disks using interlayer tapes by spark plasma sintering

摘要

A1N and graphite disks were successfully joined using a polymer plasticized ceramic tape as the interlayer by spark plasma sintering (SPS). The tape contains either composite powders of A1N and graphite or A1N powders without graphite. Both tapes contained 5 mass% Y_2O_3 as the sintering aid of A1N. The joining was carried out at 1700-1900 ℃ and 30 MPa for 5 min. No other reaction phase except for Al_2Y_4O_9 was identified in the joints. The maximum tensile strength of the joints was obtained when the AIN-graphite composite interlayer tape was used. The joining mechanism is attributed not to the chemical bonding, but to the physical bonding of the Al_2Y_4O_9 phase, which is solidified from the molten Al-Y-O squeezing into the porous graphite under pressure during SPS.