Effect of equal channel angular pressing on grain refinement and texture evolution in a biomedical alloy Ti13Nb13Zr

Abstract

Evolution of texture and concomitant grain refinement during Equal Channel Angular Pressing (ECAP) of Ti - 13Nb - 13Zr alloy has been presented. Sub-micron sized equiaxed grains with narrow grain size distribution could be achieved after eight pass at 873 K. A characteristic ECAP texture evolved in alpha phase till four passes while the evolution of characteristic ECAP texture in the beta phase could be observed only beyond the fourth pass. On increasing the deformation up to eight passes, the texture in alpha phase weakens while the beta phase shows an ideal ECAP texture. A weaker texture, low dislocation density and high crystallite size values in alpha phase suggest the occurrence of dynamic recrystallization. The absence of texture evolution in beta phase till four passes can be attributed to local lattice rotations. The characteristic ECAP texture in the eight pass deformed sample is attributed to delayed dynamic recrystallization in the beta phase. (C) 2013 Elsevier Inc. All rights reserved.