Fabrication of T13AIC2/Al_2O_3 Nanocomposite by a Novel Method

摘要

A Ti_3AlC_2/Al_2O_3 nanocomposite was synthesized using Ti, Al, C and TiO_2 as raw materials by a novel combination of high-energy milling and hot pressing. The reaction path of the 3Ti-8C-16Al-9TiO_2 mixture of powders was investigated, and the results show that the transitional phases TiC, Ti_xAl_y and Al_2O_3 are formed in high-energy milling first, and then Ti_xAl_y is transformed to the TiAl phase during the hot pressing. Finally, a reaction between TiC and TiAl occurs to produce Ti_3/AlC_2 and the nanosized Ti_3AlC_2/Al_2O_3 composite is synthesized. The Ti_3AlC/Al_2O_3 composite possessed a good combination of mechanical properties with a hardness of 6.0 GPa, a flexural strength of 600 MPa, and a fracture toughness (K1c) of 5.8 MPa-m~(1/2). 'The strengthening and toughening mechanisms were also discussed.