V. Stolyarov, Mechanical Engineering Research Institute, Moscow, Russia; A. Sergeeva, U. Ugurchiev, Moscow State Industrial Insitute, Moscow, Russia; D. Gunderov, E. Prokofiev, A. Lukyanov, Ufa State Aviation Technical University, Ufa, Russia
It is known that ultrafine-grained (UFG) shape memory TiNi alloys processed by methods of severe plastic deformation (SPD), for example, by equal channel angular pressing (ECAP), have higher functional and strength properties as compared to the coarse-grained counterparts [1,2]. Unfortunately it is very difficult to apply the subsequent metal deformation processes to high-strength UFG billets because of their insufficient deformability in rolling, extrusion and drawing. Therefore, the possibility of using electroplastic effect (EPE) [2, 3] for the deformation of UFG TiNi alloy, as well structure-phase transformations and technological features related with it are considered.
The Ti49.4Ni50.6 bars in a UFG state were an object of the investigation. The UFG state was processed by ECAP with an additional deformation for samples elongation. The samples for EPE represented pieces of 2x5x150 mm. The samples were subjected to electroplastic deformation (EPD) with a variation of rolling regimes and pulse current.
There were carried out structural investigations, mechanical tensile tests, technological investigations of deformability and widening. In the report the data obtained for UFG samples subjected to current rolling and free of current one are discussed.
The work was supported by Russian Federation Agency on Science and Innovation, project 02.513.11.3137
Summary: Electropulse post-deformation of the ultrafine-grained shape memory TiNi alloy processed by equal channel angular pressing has been investigated. Enhanced service and technological properties during cold rolling with pulse current are discovered.
