Temperature profiles in a Ti–45Ni–5Cu (at%) shape memory alloy developed by the Joule heating

Stress serration and arch-shaped Lüders stress plateau behaviour of Ti–50.8 at% Ni wire prepared by selective electrical resistance over-aging

“…Joule heating of NiTi wires is also used for some specific applications, such as shape setting for artificial biometric fingers [31] and microelectromechanical system (MEMS) devices [32,33]. Such unconventional heat treatment techniques also offer opportunities to create novel properties, such as functionally graded NiTi materials [22,34].…”

“…Whereas most of the fundamental understanding of the effects of heat treatment has been achieved historically for homogeneous heating conditions, as in the case of inside a furnace, some more complex heat treatment conditions are becoming more frequently used, for example joule heating of thin wire materials [22][23][24], laser scan for surface heating of thin films [25] and thin plates. Such heat treatments impose unique characteristics, for example extremely high heating rates up to 3500 C°s −1 [26] and gradient temperature profiles along the length of a wire [22] or through the thickness of a plate [27].…”

“…Whereas most of the fundamental understanding of the effects of heat treatment has been achieved historically for homogeneous heating conditions, as in the case of inside a furnace, some more complex heat treatment conditions are becoming more frequently used, for example joule heating of thin wire materials [22][23][24], laser scan for surface heating of thin films [25] and thin plates. Such heat treatments impose unique characteristics, for example extremely high heating rates up to 3500 C°s −1 [26] and gradient temperature profiles along the length of a wire [22] or through the thickness of a plate [27]. It has also been reported that laser welding of austenitic NiTi can cause the occurrence of martensite in the heat-affected zone and in the fusion zone at room temperature, due to the compositional variation and change of local transformation temperatures in these sensitive regions during the welding process [28,29].…”

Thermo-mechanical behavior of shape memory alloy spring actuated using novel scanning technique powered by ytterbium doped continuous fiber laser

“…Many researchers have studied the shape recovery behavior i.e. thermally induced actuation, as shown in figure 1, using different heating methodologies, such as Joule heating [34][35][36][37][38][39], hot fluidic actuation [18,[40][41][42], laser actuation [43][44][45][46], electromagnetic heating [47,48] and RF electromagnetic actuation [49,50]. In general, Joule heating of SMA element is simple and used widely but requires electrical insulation from other metal/conductive components for safety and better energy efficiency.…”

Induction heating of a shape memory alloy beam

“…The main factor of the process is the heating time or cooling time to change phase. Joule heating is a good candidate to decrease the heating time [2]. The induction heating has been evaluated for wires, as well as tubes in torsion and recently considered in the case of beams [3] but only in the case of small deformations (i.e.…”