Elemental blended powders semisolid forming of Ti-Al based alloys

Ti-6Al and Ti-6Al-4V alloys fabricated by semisolid forming are investigate d with microscopic observation, density measurements, X-ray diffraction and mechanical property tests. The effects of the forming pressure, the formin g temperature, and the forming loading time on the density of the green com pacts are discussed. The shaped green-compact that is prepared by semisolid forming method transforms into intermetallics during the further alloying heat treatment. Pore-free green compacts are obtained under almost all the selective forming conditions. However, pores often appear after alloying he at treatment. The forming loading time has a relatively strong influence on the density of the compact. Experiments have also been carried out on vari ous alloying treatments and the effects of the alloying treatment condition s on the mechanical properties of the compacts. It has been demonstrated th at Ti-6Al-4V alloy can be fabricated by semisolid forming and the optimum a lloying treatment conditions are at 1473 K treating for 7.2 ks, which can r esult in the best ultimate tensile strength of 1050 MPa and the elongation of 10% in excess of that of the plastic materials. (C) 2000 Kluwer Academic Publishers.