Abstract:α₂+γ dual phase TiAl intermetallics had been synthesized with elemental powder mixtures at high temperature. The consolidated samples were prepared by thermal extrusion of steel canned TiAl compacts. The thermal extrusion was carried out at 1 200 ℃, with extrusion ratios of 4, 8 and 16. The study on microstructures and mechanical properties showed that with increasing extrusion ratio, the porosity of the compacts as well as grain size decreased, the bending strength increased. After heat treatment the bending strength of the specimens with the extrusion ratio of 16 could increase to 897 MPa. After the thermally extruded compact had been HIPped, though the density increased slightly, the bending strength decreased partly due to grain size coarsening.

Key words: powder metallurgy TiAl intermetallics thermal extrusion elemental powders