Fabrication of TiAl by blended elemental powder semisolid forming

Semisolid forming from blended elemental powders is investigated on Ti-Al alloy. The effects of the forming pressure, temperature, and pressure holding time on the density of the green billets are discussed. The forming method is outlined as follows: the mixture of the blended elemental powders are filled in a metal mold, and heated to approximately the melting point of aluminum. Thereafter, the forming pressure is loaded and held for the prescribed time. The pore-free green compacts are obtained under almost all the present forming conditions. However, pores are observed after alloying heat treatment. The volume fraction of the pores depends on the microstructures of the green billets. Experiments have also been carried out on the effects of the alloying heat treatment conditions on the mechanical properties of the compacts. (C) 2001 Kluwer Academic Publishers.