Microstructure of TiC particle reinforced titanium matrix composite

The microstructure of two kinds of TiC particle reinforced titanium matrix composites, TiC+Ti-6Al-4V and TiC+TiAl-Sn-Zr-Mo-Si, have been investigated and analyzed in this paper. The composites were prepared by pre-treatment melting process (PTMP) at Northwest Institute for Nonferrous Metal Research (NIN). The microstructure of the composite varies with heat treatment conditions. High temperature heat treatment quickens the spheroidization tendency of a phase, decreases the amount of a phase, and the matrix recrystallizes. After heating at 1 050'C for 1 h, the microstructure of the composite is similar to the bimodal microstructure in a + btwo phase titanium alloys , and the a grains are small, of which the average size is only about 15 fm. The width of interface layer varies with processing conditions. If the width of interface layer is controlled around l /im, the reinforcing effect for the composite should be much better. Key words: TiC particle; titanium matrix composite; microstructure.