Assessing the morphology of selective laser melted NiTi-scaffolds for a three-dimensional quantification of the one-way shape memory effect

Author(s):  
Therese Bormann ◽  
Michael de Wild ◽  
Felix Beckmann ◽  
Bert Müller
1999 ◽  
Vol 596 ◽  
Author(s):  
W. Biegel ◽  
R. Klarmann ◽  
M. Kuhn ◽  
B. Wörz ◽  
B. Stritzker

AbstractPulsed Laser Deposition (PLD) was used to deposit La-doped Pb(Zr,Ti)O3 (PZT) thin films onto NiTi foils. The substrate alloy with composition Ni50Ti50 shows a strong shape memory effect with a transition temperature of about 80°C. This simple bicomponental system could have the potential of an actuator device (NiTi shows a strain up to 5 % during thermal cycling) with an inherent sensorial component (PZT) for the generated elongation. The deposited ceramic films were characterized with respect to their structural properties (XRD) and their ferroelectric behavior (P-E hysteresis). Under certain deposition conditions the growth of pure perovskite PZT on the polycrystalline shape memory alloy was observed. The growth morphology of PZT on NiTi was compared to the one of PZT on single crystalline substrates whereas no distinctive texture of the films on NiTi could be found. The ferroelectric behavior of the PZT films depend on the stage of bending of the film-substrate compound.


2019 ◽  
Vol 136 ◽  
pp. 103085 ◽  
Author(s):  
Giulia Scalet ◽  
Fabrizio Niccoli ◽  
Cedric Garion ◽  
Paolo Chiggiato ◽  
Carmine Maletta ◽  
...  

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
V.V. Koledov ◽  
◽  
V.G. Shavrov ◽  
S.V. von Gratovsky ◽  
P.V. Lega ◽  
...  

In this work we give an overview of researches, conducted in the framework of the project RFBR-BRICS, together with groups from Brazil, Russia, India, China and South Africa on the development of new technology nanoassembly «bottom-up» various devices for nanoelectronics, nanosensors, biomedicine and basic research based on the use of new functional materials with phase transitions and new physical effects. The Russian group carried out work on improving the nanomanipulation system based on nanotweezers made of Ti2NiCu alloy with shape memory effect. A new design of the control system is proposed, which reduces the control power of the resistive heater and reduces the uncontrolled drift of the nanotweezers by up to 5 times. In the process of joint technological, design and physical research in the field of nanomanipulation and nanoassembly technology, the following main results were obtained by the participating groups. The Indian group, together with the Russian group, studied the melting processes at the micro-level of dimensions, and showed the possibility of manipulating a drop of molten gallium with the help of electromigration and the formation of contact chains for nanoassembly without the use of lithography. Also, the Russian and Indian groups studied the possibility of individual manipulation of microparticles in the liquid. The Chinese group, together with the Russian one, manufactured and tested a prototype of a spin-injection microwave electromagnetic oscillator for nanosensory applications. The Russian and South African groups produced "bottom-up" nanoassembly of carbon nanomaterials, such as CNT, decorated with magnetic ions and nanodiamonds ring structures, and they were searched for quantum effects such as quantum oscillations of transport properties and superconductivity. The Brazilian, Chinese and Russian groups jointly produced prototypes of nano-bio-sensors based on field-effect transistors made of suspended semiconductor nanowires using the bottom-up nanosembly method. Two original approaches to nanoassembly were used: a variant of the traditional scheme with liquid transportation of nanowires and an approach based on three-dimensional manipulation using the nanotweezers with a shape memory effect.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adelaide Nespoli ◽  
Nicola Bennato ◽  
Enrico Bassani ◽  
Francesca Passaretti

Purpose This paper aims to examine customized NiTi jewels with functional properties fabricated through four-dimensional (4D)-printing. Design/methodology/approach Two opened rings are fabricated through selective laser melting starting from 55.2Ni-Ti (wt.%) micrometric powder. After the additive process the two rings present the one-way shape memory effect (OWSME). A specific training is accomplished on one of the two printed rings to promote the two-way shape memory effect (TWSME). Both the samples, namely, the rings, respectively, presenting the OWSME and TWSME property, follow a series of post-processing routes to improve the surface finish. Furthermore, a thermal treatment at high temperature is used to create a thin colored oxide layer on the sample surface. Findings Results show that the change of shape owing to the OWSME and TWSME properties allows the customized 4D-printed rings to be adaptable to environmental changes such as load and temperature variations. This adaptability improves comfort and fit of the jewels. Originality/value To the best of the authors’ knowledge, in this work, first cases of additively manufactured NiTi jewels are reported to propose innovative solutions in the design and processing industry of jewels.


2013 ◽  
Vol 738-739 ◽  
pp. 344-347 ◽  
Author(s):  
Józef Lelątko ◽  
Zdzisław Lekston ◽  
Tadeusz Wierzchoń ◽  
Tomasz Goryczka

In order to increase corrosion resistivity of the NiTi alloy the surface is covered by layers. Layers can be made from such as titanium nitrides and/or oxides as well as their mixture. Recently, a glow discharge technique has been applied for coatings formation. However, the deposition process requires to be done at elevated temperature. Therefore, it may have a negative effect on the structure, which is responsible for the shape memory phenomena. The results obtained from studies, done over the influence of the glow discharge nitriding and combination of nitriding and oxidizing process on the structure, the kinetics of martensitic transformation, the one-way shape memory effect and the superelasticity effect of the NiTi alloys are reported. The results showed that during deposition process, curried out at temperatures above 250°C and for time up to 30 minutes, the precipitation of dispersive particles of Ni4Ti3 phase already starts and has a positive effect on the superelasticity phenomena. The applied deposition technique does not affect also negatively the shape memory effect.


2019 ◽  
Vol 54 (12) ◽  
pp. 9235-9246 ◽  
Author(s):  
Xiaodong Peng ◽  
Hui He ◽  
Yunchao Jia ◽  
Hao Liu ◽  
Yi Geng ◽  
...  

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