Influence of partial static recrystallization on microstructures and mechanical properties of NiTiFe shape memory alloy subjected to severe plastic deformation

摘要

Severe plastic deformation (SPD) and subsequent annealing are performed to investigate the influence of partial static recrystallization on microsturctures and mechanical properties of NiTiFe shape memory alloy (SMA), where Schmid factor, slip system, texture evolution and geometrically necessary dislocation are considered. The results show that partial static recrystallization substantially influences the microstructures and mechanical properties of NiTiFe SMA. The grain size of the annealed NiTiFe SMA is much smaller than that of the as-rolled one when the fraction of static recrystallization is relatively lower, which is due to the fact that plenty of recrystallized nucleus are initiated because a high density of dislocations are induced by SPD and they have no enough time to grow. The annealed NiTiFe samples with smaller grain size possess lower strength and more perfect plasticity than the as-rolled one, which is attributed to the fact that the samples possess different texture along the compression direction. (C) 2016 Elsevier Ltd. All rights reserved.