Hydrostatic Extrusion (HE) as one of the methods of grain refinement of metallic materials down to the nanometric scale [1-4]. The main features of this method are large strain and very high strain rates (exceeding than 104 s-1). HE also offers the opportunity to obtain bulk materials in a variety of forms (rods and wires of complex cross-sections, small tubes). HE processing proved to be an efficient way to reduce the grain size in Ti. This grain refinement resulted in significantly improved mechanical properties.
The material examined in the study was commercially pure titanium with intermetallic Ti-Al layers. This material was subjected to HE at room temperature. The intermetallic layers were produced by magnetron sputtering followed by glow discharge assisted treatment. The HE of coated specimens resulted in substantial grain size refinement in titanium. As a consequence of such microstructure evolution the mechanical properties of this material are significantly improved. The intermetallic Ti-Al layers effected reduction of the pressure during extrusion of pure titanium and additionally increased microhardness and frictional wear of the material.

References:
1. K.J.Kurzydłowski, H.Garbacz, M.Richert: Rev. Adv. Mater. Sci. 8(2004)129
2. M.Lewandowska, H.Garbacz, W.Pachla, A.Mazur, K.J.Kurzydłowski: Solid State Phenomena 101(2005)65
3. M.Lewandowska, H.Garbacz, W.Pachla, A.Mazur, K.J.Kurzydłowski: Material Science-Poland
4. M.Kulczyk, W.Pachla, H.Garbacz, M.Lewandowska, A.Mazur, K.J.Kurzydłowski: Material Science-Poland (2005) accepted