Variation in TiNi alloy properties on room temperature holding

Abstract

The aim of the present work was to investigate the influence of room temperature holding on martensitic transformations temperatures and resistivity in TiNi shape memory alloy, which was previously subjected to thermal cycling. The recovery in the martensitic transformation temperatures and resistivity was found during room temperature holding of the TiNi alloy that was subjected to preliminary thermal cycling. It was shown that the recovery in martensitic transformation temperatures and resistivity depend on the number of thermal cycles. It is assumed this was caused by the dependence of the intensity of recovery on the dislocation density. The larger the number of cycles, the higher the defect density and the more intensive relaxation occurred during holding. It was found that the dislocation structure that formed during deformation in martensite was more stable during room temperature holding then the structure which appeared during thermal cycling.