Study of Structure and Phase Transformations in Rejuvenated Rapidly Quenched TiNiCu Alloys

Alloys of the quasibinary TiNi-TiCu system manufactured by melt quenching in form thin 20–50 μm ribbons have proven to show good potential as materials for fabrication micromechanical devices. At high cooling rates (about 106 K/s), this method allows producing high-copper (more than 20 at.%) amorphous alloys which exhibit an excellent shape-memory effect after crystallization. Their properties are known largely depend on crystallization conditions and structure initial material acting a precursor formation crystal phases. It has been shown recently that rejuvenation procedure (cryogenic thermocycling) metallic glasses is one most promising methods improving their properties. In study, we investigated first time cryogenic thermocycling rapidly quenched TiNiCu state, well phase transformation patterns subsequent conducted using various methods. The was analyzed utilizing scanning transmission electron microscopy, X-ray diffraction analysis, differential calorimetry. results treatment slightly reduces glass transition onset temperatures moderately changes sizes structural features (grains, martensite plates), quantity phase, characteristic enthalpy martensitic transformation.