The microstructure and mechanical characteristics of the alloy Ti-50.7 at.%Ni with different deformation processing during multiple martensitic transformations

Abstract

Abstract The influence of thermal cycling in the temperature range of B2-B19’ martensitic transformations on the TiNi alloy structure and properties are studied. Different states are considered, namely the initial coarse-grained (CG) state, the ultrafine-grained (UFG) state after ECAP, the state after ECAP and cold upsetting by 30%. It is shown that, as a result of thermal cycling, microhardness and strength grow in all the three states. According to the data from TEM analysis, the increment of the dislocation density is observed, resulting from thermal cycling.