Fully dense submicrocrystalline intermetallic/ceramic composites based on the system Ti-Al-Si are prepared by high energy milling and subsequent hot isostatic pressing (HIP). To avoid interstitial impurities like oxygen or nitrogen, all handling and processing is conducted under vacuum or controlled gas atmospheres (Ar or Ar-5 vol.% H-2). In the first part of the present study, argon pick-up during high energy milling is investigated - a general problem that has to be considered when preparing materials by powder metallurgical processing routes. Annealing experiments above the HIP temperature of the Ti-Al-Si-composites lead to the evolution of pores. Analytical and microstructural investigations demonstrate that the formation of this voids is caused by entrapped Ar atoms (concentration: similar to 60 mug/g). Upon annealing, Ar can diffuse, leading to a rearrangement of small Ar-filled nanopores and a coarsening of the pores. The overall density of the components is not affected by this process. By further increasing the temperature, the interior gas pressure of the pores may exceed the flow stress of the material and thus contribute to an inflating of the samples. In this case. the increase in porosity is confirmed by a drop in density. Tension tests on heat treated specimens elucidate the effect of (nano-)pores on the mechanical behavior. Finally, solutions for avoiding argon pick-up and porosity will be suggested. The second part of this study deals with hot-forming of submicrocrystalline intermetallic/ceramic composites. Due to the ultrafine grained microstructure these materials show excellent mechanical properties with regard to easy workability. During hot-forming, finely dispersed silicides along the grain boundaries of the equiaxed gamma-TiAl grains prevent coarsening of the matrix. Therefore, the deformation temperatures for processing techniques like extrusion or isothermal forging can be kept about 200 degreesC below those for conventional gamma-TiAl alloys. This shows that high energy milling is an attractive processing route for the synthesis of easily workable precursor materials.