Diffusion bonding of Ti3AlC2 ceramic via a Si interlayer

Based on the structure characteristic of Ti3AlC2 and the easy formation of Ti3Al1 – xSixC2 solid solution, a Si interlayer was selected to join Ti3AlC2 layered ceramic by diffusion bonding method. Joining was performed at 1,300–1,400 C for 120 min under 5 MPa load in an Ar atmosphere. The phase composition and interface microstructure of the joints were investigated by XRD, SEM and EPMA. The results revealed that Ti3Al(Si)C2 solid solution formed at the interface. The mechanism of bonding is attributed to silicon diffusing inward the Ti3AlC2. The strength of joints was evaluated by a 3-point bending test. The jointed specimens exhibit a high flexural strength of 285 ± 11 MPa, which is about 80% of that of the Ti3AlC2; and retain this strength up to 1,000 C. The high mechanical performance of the joints indicates that diffusion bonding via a Si interlayer is effective to bond Ti3AlC2 ceramic.