Controlling the phase transformation window during stages of hot/cold forging of Ni-rich Ni–Ti alloy

A detailed microstructural analysis during the intermediate stages of fabrication NiTi orthodontic archwire is carried out in this study. These findings were related to phase transformation characteristics such as start and finish temperature, thermal hysteresis, etc. The objective was monitor window different thermomechanical processing. casted alloy further subjected combinations hot cold forging steps with annealing. Four sample conditions prepared. microstructure development these samples studied through electron back-scattered diffraction synchrotron radiation X-ray (SR-XRD) techniques. temperatures determined by differential scanning calorimetric measurements. microstructures showed grain boundary serrations, very large grains austenite, twin-like features within austenite mixed-phase distribution martensite. differences also clear terms local in-grain misorientation fractions. SR-XRD measurements revealed possible precipitation Ni 4 Ti 3 Ti. martensite temperature ( M s ) seen be a function high angle fraction, while f an inverse trend. interval, – stored energy that determines driving force overcome frictional work opposing movement habit plane, largely depends on elastic plates its growth. hysteresis reverse (M ? A) misorientation.