Low Pressure Joining of SiCf/SiC Composites Using Ti3AlC2 or Ti3SiC2 MAX Phase Tape

SiCf/SiC composites were joined using a 60 mu m-thick Ti3AlC2 or Ti3SiC2 MAX phase tape. The filler tape was inserted between the SiCf/SiC composites containing a 12 wt.% Al2O3-Y2O3 sintering additive. The joining was performed to a butt-joint configuration at 1600 degrees C or 1750 degrees C in an Ar atmosphere by applying 3.5 MPa using a hot press. Microstructural and phase analyses at the joining interface confirmed the decomposition of Ti3AlC2 and Ti3SiC2, indicating the joining by solid-state diffusion. The results showed sound joining interface without the presence of cracks. Joining strengths higher than 150 MPa could be obtained for the joints using Ti3AlC2 or Ti3SiC2 at 1750 degrees C, while those for joined at 1600 degrees C decreased to 100 MPa approximately without the deformation of the joining bodies. The thickness of initial filler tape was reduced significantly after joining because of the decomposition and migration of MAX phase owing to the plasticity at high temperatures.