TY - JOUR
T1 - Effect of thermal cycling on the transformation temperature ranges of a Ni-Ti shape memory alloy
AU - Dos Santos Paula, Andersan
AU - Canejo, João Paulo Heitor Godinho
AU - Martins, Rui Miguel dos Santos
AU - Braz Fernandes, Francisco Manuel
PY - 2004/7/25
Y1 - 2004/7/25
N2 - Shape memory alloys (SMA) represents a class of metallic materials that has the capability of recovering a previously defined initial shape when subject to an adequate thermomechanical treatment. The present work aims to study the influence of thermal cycles on the transition temperatures of a Ni-Ti alloy. In this system, small variations around the equiatomic composition give rise to significant transformation temperature variations ranging from 173 to 373 K. SMA usually presents the shape memory effect after an annealing treatment at ca. 973 K. The optimisation of the thermomechanical treatment will allow to "tune" the material to different transformation temperature ranges from the same starting material, just by changing the processing conditions. Differential scanning calorimeter (DSC) and in situ high-temperature X-ray diffraction (XRD) have been used to identify the transformation temperatures and the phases that are present after different thermal cycles. The results concerning a series of thermal cycles with different heating and cooling rates (from 1.67 × 10-2 to 1.25 × 10-1 K/s) and different holding temperatures (from 473 to 1033 K) are presented.
AB - Shape memory alloys (SMA) represents a class of metallic materials that has the capability of recovering a previously defined initial shape when subject to an adequate thermomechanical treatment. The present work aims to study the influence of thermal cycles on the transition temperatures of a Ni-Ti alloy. In this system, small variations around the equiatomic composition give rise to significant transformation temperature variations ranging from 173 to 373 K. SMA usually presents the shape memory effect after an annealing treatment at ca. 973 K. The optimisation of the thermomechanical treatment will allow to "tune" the material to different transformation temperature ranges from the same starting material, just by changing the processing conditions. Differential scanning calorimeter (DSC) and in situ high-temperature X-ray diffraction (XRD) have been used to identify the transformation temperatures and the phases that are present after different thermal cycles. The results concerning a series of thermal cycles with different heating and cooling rates (from 1.67 × 10-2 to 1.25 × 10-1 K/s) and different holding temperatures (from 473 to 1033 K) are presented.
KW - differential scanning calorimetry
KW - phase transformations
KW - in situ high-temperature XRD
KW - heat treatment
KW - Ni-Ti shape memory alloys
KW - Ni-Ti shape memory alloys
KW - Phase transformations
KW - Differential scanning calorimetry
KW - Heat treatment
KW - In situ high-temperature XRD
UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-3042783214&origin=resultslist&sort=plf-f&src=s&st1
U2 - 10.1016/j.msea.2003.11.057
DO - 10.1016/j.msea.2003.11.057
M3 - Conference article
SN - 0921-5093
VL - 378
SP - 92
EP - 96
JO - Materials Science and Engineering: A-Structural Materials Properties Microstructure and Processing
JF - Materials Science and Engineering: A-Structural Materials Properties Microstructure and Processing
IS - 1-2
T2 - European Symposium on Martensitic Transformation and Shape-Memory
Y2 - 1 January 2003
ER -