Abstract: Mo_f/Ti48Al composite was successfully prepared by foil-fiber-foil method and hot pressing sintering, and the effects of Mo fiber on the microstructure and mechanical properties of the TiAl alloy were analyzed. The results show that through the two-step low temperature hot pressing of 635 ℃, 3 MPa for 10 h+680 ℃, 3 MPa for 4 h, the Al has fully reacted and the TiAl foil laminated material forms a dense Ti/TiAl₃ plate nearly void-free. Then in the high temperature reaction annealing at 1200 ℃ for 36 h, Ti and TiAl₃ continue to react to form γ-TiAl and α-Ti₃Al phases. The diffusion reaction of Mo fiber with matrix alloy after high temperature annealing forms a diffusion region, in which the main phases are TiMo and AlMo₃. The Mo fiber and matrix alloy are closely combined through diffusion, and there are no voids or cracks formed in the interface. Compared with the alloy without adding Mo fiber, the flexural properties of the composite with 10vol% Mo fiber are obviously improved, and the Mo fiber plays a toughening role in the alloy.

Key words: titanium aluminum alloy, molybdenum fiber, foil-fiber-foil method, hot pressing sintering