TY - JOUR
T1 - Functionally graded shape memory alloys
T2 - Design, fabrication and experimental evaluation
AU - Samsam Shariat, Bashir
AU - Meng, Qinglin
AU - Mahmud, Abdus S.
AU - Wu, Zhigang
AU - Bakhtiari, Reza
AU - Zhang, Junsong
AU - Motazedian, Fakhrodin
AU - Yang, Hong
AU - Rio, Gerard
AU - Nam, Tae hyun
AU - Liu, Yinong
PY - 2017/6/15
Y1 - 2017/6/15
N2 - Functionally graded shape memory alloys have the advantage of combining the functionalities of the shape memory effect and those of functionally graded structures. By proper design, they can exhibit new and complex deformation behaviour that is unmatched in uniform shape memory alloys. One obvious advantage of functionally graded shape memory alloys is their widened transformation stress and temperature windows that provide improved controllability in actuating applications. This paper reports on the concept, fabrication, experimentation and thermomechanical behaviour of several designs of functionally graded NiTi alloys, including compositionally graded, microstructurally graded and geometrically graded NiTi alloys, and the various techniques that may be used to create these functionally graded materials. It is found that the property gradients created along the loading direction or perpendicular to the loading direction produce distinct thermomechanical behaviours. The property gradient along the loading direction provides stress gradient over stress-induced transformation, which can be adjusted by the property gradient profile. The property gradient through the thickness direction of plate specimens and perpendicular to the loading direction provides four-way shape memory behaviour during stress-free thermal cycling after tensile deformation.
AB - Functionally graded shape memory alloys have the advantage of combining the functionalities of the shape memory effect and those of functionally graded structures. By proper design, they can exhibit new and complex deformation behaviour that is unmatched in uniform shape memory alloys. One obvious advantage of functionally graded shape memory alloys is their widened transformation stress and temperature windows that provide improved controllability in actuating applications. This paper reports on the concept, fabrication, experimentation and thermomechanical behaviour of several designs of functionally graded NiTi alloys, including compositionally graded, microstructurally graded and geometrically graded NiTi alloys, and the various techniques that may be used to create these functionally graded materials. It is found that the property gradients created along the loading direction or perpendicular to the loading direction produce distinct thermomechanical behaviours. The property gradient along the loading direction provides stress gradient over stress-induced transformation, which can be adjusted by the property gradient profile. The property gradient through the thickness direction of plate specimens and perpendicular to the loading direction provides four-way shape memory behaviour during stress-free thermal cycling after tensile deformation.
KW - Functionally graded material (FGM)
KW - Heat treatment
KW - Martensitic transformation
KW - NiTi
KW - Pseudoelasticity
KW - Shape memory alloy (SMA)
UR - http://www.scopus.com/inward/record.url?scp=85016803151&partnerID=8YFLogxK
U2 - 10.1016/j.matdes.2017.03.069
DO - 10.1016/j.matdes.2017.03.069
M3 - Article
AN - SCOPUS:85016803151
VL - 124
SP - 225
EP - 237
JO - MATERIALS & DESIGN
JF - MATERIALS & DESIGN
SN - 0264-1275
ER -