RAMOS, A. P.; http://lattes.cnpq.br/1756790885236814; RAMOS, Alana Pereira.
Resumo:
Ternary alloys with shape memory Ti-Cu-Ni are known to submit a characteristic
phase transformation and properties similar to the and Ti-Ni binary alloy . Studies
with rich-copper alloys showed that the addition of copper in alloys Ti-Ni reduces
the hysteresis response of the shape memory effect and increases the TFA
(tendency to form amorphous phase) still little studied with high percentages of
copper. Thus, this study aimed to evaluate the influence of cooling rate on the
transformation temperatures and on the tendency of Cu-Ni-Ti ribbons rapidly
solidified. Therefore, two ribbons TI01 (Ti 43.5 Cu 37.8 Ni 18.7) and Ti02 (Ti 58.4 Cu 25.6
Ni 16.0) were produced by melt spinning process, varying the wheel linear velocity
21 m/s and 63 m/s. The samples were characterized using DSC, X-DR, RET and
MO and techniques. Melt spinning technique allows the production of very thin
ribbons of the order of microns, in one processing step, as it was also possible to
produce amorphous ribbons, the system Ti-Cu-Ni, without crystalline phase as
observed in TI01 and 02 Ti02 with linear velocity of 63m/s. The heat treatment was
sufficient to remove all defects produced by rapid solidification process and
produce a rapid grain growth, favoring the increase of temperatures of martensitic
and austenitic transformation.
