Papers by Author: Tamás Törköly

Abstract: Ultrafine-grained titanium was processed by severe plastic deformation (SPD). The SPD was carried out by equal channel angular pressing (ECAP) at high temperature. The ECAPprocessed sample was further deformed by conventional techniques such as radial forging and drawing. The microstructure was characterized quantitatively by X-ray diffraction line profile analysis and transmission electron microscopy after each step of deformation. The effect of procesing routes on the mechanical behavior was also studied. It was found that the conventional deformation processes after ECAP result in further increment in dislocation density and strength at the expense of ductility.

Abstract: The relative low density of aluminum is well known for a long time, but its adaptability is limited by mechanical and thermal expansion properties. These unfavorable properties can be significantly improved by powder metallurgy. The produced material has a non-equilibrium state; it follows from the power metallurgy, so arises the question of the measurement of residual stress. We produced some square rod for our experiment with different tool geometry, thus the deformation histories of this specimens were different too. We measured the residual stress of this specimens by means of strain-gauges.