Rapid transient-liquid-phase bonding of Al2O3 with microdesigned Ni/Nb/Ni interlayers

The vast majority of man-made devices contain joints between similar or dissimilar materials. Ideally, joining is fast, reliable, and inexpensive. In this work we demonstrate that robust refractory joints between Al2O3 bodies can be produced rapidly and consistently by a transient-liquid-phase bonding process exploiting microengineered multilayer Ni/Nb/Ni interlayers. Samples were bonded for times ranging from 5 min to 6 h at 1400 degrees C. Well-bonded assemblies were produced in all cases. Interlayers with remelt temperatures >2200 degrees C were achieved in as little as 5 min at 1400 degrees C. In room-temperature bend tests, fractures initiated and propagated almost exclusively in the ceramic. Extension of this approach to other advanced ceramics should be possible, providing a rapid and reliable alternative to conventional joining approaches.