Utilizing the exothermic reaction between TiO2, Al and B powders, the Al2O3-TiB2 composite ceramics and the in-situ formed A12O3 and TiB2 particulates reinforced Al composite were fabricated at lower temperature by reaction sinter method. Al2O3-TiB2 is porous ceramics with 80% of theoretical density, and its grain is consisted of growth units with a size of about 10μm. There was small amount of Al3Ti in the ceramics. The in-situ formed Al2O3 and TiB2 particulates with a size of less than 2μm are uniformly d...