Diffusion bonding of Ti₃AlC₂ ceramic via a Si interlayer

Abstract

Based on the structure characteristic of Ti₃AlC₂ and the easy formation of Ti₃Al_1 − x Si _x C₂ 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.