Abstract
Active metal brazing of a new high thermal conductivity sintered SiC-polycrystalline fiber-bonded
ceramic (SA-Tyrannohexs) has been carried out using a Ti-containing Ag–Cu active braze alloy
(Cusil-ABAs). The brazed composite joints were characterized using scanning electron microscopy
coupled with energy-dispersive X-ray spectrometry (SEM–EDS). The results show that this material can
be successfully joined using judiciously selected off-the shelf active braze alloys to yield metallurgically
sound joints possessing high integrity. Uniform and continuous joints were obtained irrespective of
differences in the fiber orientation in the substrate material. Detailed interfacial microanalysis showed
that the titanium reacts with C and Si to form TiC layer and a Ti–Si compound, respectively.
Furthermore, the evaluation of shear strength of the joints was also conducted at ambient and elevated
temperatures in air using the single-lap offset (SLO) shear test. The perpendicular-type SA-Tyrannohex
joints exhibited apparent shear strengths of about 42 MPa and 25 MPa at 650 1C and 750 1C,
respectively. The fracture at the higher temperature occurred at the interface between the reactionformed
TiC layer and braze. This might be caused by generation of stress intensity when a shear stress
was applied, according to m-FEA simulation results.