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Improving the Recovery Capability and Phase Composition of NiTi Shape Memory Alloy Wires by High-Density Pulsed Electric Current Treatment
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G
J
DOI:10.1007/s11665-026-13761-x.png)
Abstract
En 中文
This study demonstrates that high-density pulsed electric current (HDPEC) treatment enhances the performance of NiTi shape memory alloy (SMA) wires through short, non-equilibrium electrical stimulation enabling both annealing and recovery. At the optimal HDPEC annealing condition of a single pulse at 310 A for 10 ms, HDPEC-driven recovery achieved complete shape recovery, whereas conventional heat treatment (CHT)-annealed wires reached only 52.9% recovery. Even under severe bending deformation, HDPEC-treated wires kept recovery ratios above 80%. Moreover, 90.7% recovery was achieved at a low recovery current of 90 A while the bulk temperature remained below the austenite finish temperature (Af), indicating that HDPEC can activate recovery under reduced thermal loads via combined thermal and athermal contributions. X-ray diffraction analysis revealed a marked increase in the B2 austenite phase fraction together with grain refinement to approximately 15-20 nm. In contrast to CHT annealing and recovery routes, HDPEC preserves a nanocrystalline microstructure while enabling effective phase reversion. Overall, HDPEC provides a localized and energy-efficient pathway for improving recoverability and microstructural stability of SMA wires, offering strong potential for low-power shape memory alloy-based actuators and flexible robotic systems.
Keywords:
B2 austenite
bending recovery
high-density pulsed electric current
shape memory alloy
XRD analysis
Journal
J
IF:
2
Papers:
1.8K
Citations:
0
