A jumping shape memory alloy under heat

Abstract

Shape memory alloys are typical temperature-sensitive metallic functional materials due to superelasticity and shape recovery characteristics. The conventional shape memory effect involves the formation and deformation of thermally induced martensite and its reverse transformation. The shape recovery process usually takes place over a temperature range, showing relatively low temperature-sensitivity. Here we report novel Cu-Al-Fe-Mn shape memory alloys. Their stress-strain and shape recovery behaviors are clearly different from the conventional shape memory alloys. In this study, although the Cu-12.2Al-4.3Fe-6.6Mn and Cu-12.9Al-3.8Fe-5.6Mn alloys possess predominantly L21 parent before deformation, the 2H martensite stress-induced from L21 parent could be retained after unloading. Furthermore, their shape recovery response is extremely temperature-sensitive, in which a giant residual strain of about 9% recovers instantly and completely during heating. At the same time, the phenomenon of the jumping of the sample occurs. It is originated from the instantaneous completion of the reverse transformation of the stabilized 2H martensite. This novel Cu-Al-Fe-Mn shape memory alloys have great potentials as new temperature-sensitive functional materials.

Vision Based Supervised Restricted Boltzmann Machine Helps to Actuate Novel Shape Memory Alloy Accurately

“…The change in the relative position and shape of the SMA body compared to its original position and shape under excitement, was captured in the video frames. This dynamically changing information about shape and position were correlated with the separately measured generated force for using the proposed predictive modelling [23][24][25][26][27][28][29][30][31].…”

XGBoost automates the characterisation of reversibly actuating planar-flow-casted NiTi shape memory alloy foil

“…We aimed to design an automated and rapid SMA characterization system to achieve two primary objectives [27][28][29][30][31][32][33]. Firstly, we established a capability (aim A) to predict possible actuation angles achievable by a freshly manufactured foil, purely based on the dynamic maximum body temperature of the foil while under the thermal excitement.…”

Влияние предварительной сжимающей нагрузки на работу, производимую монокристаллами Cu-Al-Ni при взрывном восстановлении деформации памяти формы

“…DOI: 10.21883/PJTF.2022. 03.51983.19004 Способность кристаллов с эффектом памяти формы (ЭПФ) к высокоскоростному (взрывному) восстановлению деформации при обратном мартенситном превращении (ОМП) обнаружена ранее в ряде монокристаллов различных сплавов [1][2][3][4]. Однако до сих пор не оценивалась работа, производимая при этом кристаллами.…”