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Prealloyed powders of the intermetallic ␥-TiAl phase and the ceramic -Ti 5 Si 3 phase were high-energy milled and hot-isostatically pressed (HIP) to produce silicide dispersed composite materials with grain sizes in the submicron and nanometer range. The amorphous state of the as-milled powders crystallizes via a multistep decomposition reaction during degassing at 440°C and HIP. At a pressure of 200 MPa HIP-temperatures as low as 750°C are sufficient for a complete densification of the milled powder. The microstructure of the compacts is very homogeneous and consists of equiaxed ␥-TiAl crystals and -Ti 5 (Si,Al) 3 particles. Depending on the silicon content, these particles are interspersed within the grain boundary network of the ␥-TiAl phase or dispersed inside the ␥ grains. With respect to technical applications, submicron-grained composites are regarded as promising precursor materials that should allow for easy hot working in the as-prepared state as well as for high-temperature structural applications after a suitable transformation of the microstructure.

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