Abstract: An in-situ TiCP/Al composite was prepared by a thermal explosion/quick pressure method (TE/QP). The effect of Al content on the reaction temperature as well as the reaction rate has been studied. Phase constituents and the microstructure of the composites and the particle size of the reinforcement were analysed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results have shown that TiCp/Al composite with 40～70 vol. pct TiC particle reinforcement and high relative density can be directly obtained by TE/QP. TiC is the only reaction product when Al content in Al-Ti-C system is no more than 60 vol. pct, but Al3Ti phase will also form when Al content is more than 60 vol. pct. Increasing Al content prolongs the initial reaction time, reduces the highest reaction temperature and the reaction rate, and decreases the size of TiC particles. In addition, the microstructure of TiCp/Al composite and the structure of interface between TiCp and Al are studied using SEM and transmission electron microscopy (TEM). The results show that the in-situ synthesized TiC particle has fcc cubic structure. The orientation between TiC particles and Al matrix can be described as ( )Al//( )TiC and [ ]Al//[011] TiC. Results of the mechanical property tests reveal that the ultimate strength (σ) and modulus (E) are 687~MPa and 142 GPa respectively when the Al content is 40 vol. pct. On contrary,δ elongation increases by 3.2% with increasing Al content.

Key words: TiCp/Al composites, Thermal explosion/quick pressure method (TE/QP), Microstructure...