A novel core-shell TiCx particle by modifying TiCx with B element and the preparation of the (TiCx + AlN)/Al composite

Abstract

TiCx particle is a promising reinforcement in Al-based composites. However, the unstable interfaces of TiCx/Al have seriously affected the mechanical properties due to the chemical reaction throughAl + TiCx → Al4C3. By utilizing B atoms to modify the interfaces between ex-situ TiCx particles and Al matrix, the (4TiCx + 5AlN)/Al composite has been synthesized. It is confirmed that B atoms distribute as coating around the TiCx particles by the electron probe micro-analyzer (EPMA) and high resolution transmission electron microscope (HRTEM) analyses. The interfaces among Al, AlN and B-modified TiCx particles have been identified to be clean and clear. Compared with 5AlN/Al composite, the (4TiCx + 5AlN)/Al composite exhibits enhanced hardness and tensile strength. The ultimate tensile strength (UTS) of 5AlN/Al composite at room temperature (25 °C) and elevated temperature (350 °C) are 325 MPa and 143 MPa, while (4TiCx + 5AlN)/Al composite is increased to 350 MPa and 187 MPa, respectively. Except for the synergistic strengthening performance of nano AlN and submicron TiCx particles, it is regarded that the B-modified interfaces of TiCx/Al are beneficial to the load transfer strengthening. This work may provide some new insights for preparing high performance Al-based composites, by promoting the interface modification between ex-situ reinforcement and Al matrix.