Influence of Electrical Pulse on Shape Memory Effects and Phase Transition of FeMnSiCrNi Shape Memory Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 562-565
Author(s):  
Xing Jiang Liu ◽  
Yan Gao ◽  
Jin Gang Qi
Keyword(s):  
Shape Memory Alloy ◽  
Liquid Metal ◽  
Shape Memory ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Electric Pulse ◽  
Memory Effects ◽  
Grain Structure ◽  
Shape Memory Effects ◽  
Columnar Grain

This paper studies the electric-pulse applied in the solidification process of the FeMnSiCrNi shape memory alloy, by applying different pulse frequency and polarity on the FeMnSiCrNi shape memory alloy to improve the shape memory effects. The results show : electric-pulse was conducive to FeMnSiCrNi alloys grain refinement, the alloy can improve the shape memory effect of Compression deformation, the absolute shape recovery rate is improved from 2% to 3.2% which is not treated by the electric-pulse ; when the liquid metal was connected with the anode of the pulse, it is easy to get the columnar grain structure and the column spacing is smaller; when the liquid metal was connected with the cathode of the pulse, the column spacing is larger; Columnar grain is conducive to FeMnSiCrNi alloy specimens compressed shape recovery, it has the smaller column spacing, yet the shape recovery rate is higher; equiaxed is favor in bending back, columnar crystals impede the bending response.

scholarly journals Effects of a Short Heat Treatment Period on the Pullout Resistance of Shape Memory Alloy Fibers in Mortar

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2278 ◽  
Author(s):  
Min Kyoung Kim ◽  
Dong Joo Kim ◽  
Young-Soo Chung ◽  
Eunsoo Choi
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Memory Effects ◽  
Stress Recovery ◽  
Pullout Resistance ◽  
Pullout Tests ◽  
Dog Bone ◽  
Shape Memory Effects ◽  
Short Time

The feasibility of the crack closure of cementitious composites reinforced with shape memory alloy (SMA) fibers was investigated by performing single-fiber pullout tests. To demonstrate the fast crack closing ability, in this study, a heat treatment (300 °C) was applied for a short time (10 min). A short heat treatment was applied for 10 min, after the slip reached 0.5 mm, to activate the shape memory effects of cold-drawn SMA fibers. Two types of alloys were investigated, NiTi and NiTiNb, with two geometries, either smooth or dog-bone-shaped. During the heat treatment, the pullout stress of the SMA fibers initially decreased due to thermal extension, and then increased after heating for 1–3 min, resulting from the shape memory effects. However, their pullout stress recovery during and after the heat treatment was different for the different alloys and fiber geometries. The NiTi fibers generally produced a higher and faster recovery in terms of their pullout stress than the NiTiNb fibers, while the dog-bone-shaped fibers showed a faster pullout stress recovery than the smooth fibers.

Solvent-driven temperature memory and multiple shape memory effects

Soft Matter ◽  
2015 ◽  
Vol 11 (20) ◽  
pp. 3977-3985 ◽  
Author(s):  
Rui Xiao ◽  
Jingkai Guo ◽  
David L. Safranski ◽  
Thao D. Nguyen
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Memory Effects ◽  
Shape Memory Effects

Programmed Nafion specimens can achieve multi-staged shape recovery in multiple solvents.

Superelastic and Shape Memory Effects in Laminated Shape-Memory-Alloy Beams

AIAA Journal ◽  
2003 ◽  
Vol 41 (1) ◽  
pp. 100-109 ◽  
Author(s):  
S. Marfia ◽  
E. Sacco ◽  
J. N. Reddy
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Memory Effects ◽  
Shape Memory Effects

Smart Materials of Cured Epoxy Polymer Modified by 6F-PEEK with Shape Memory Effect

2010 ◽  
Vol 152-153 ◽  
pp. 530-535 ◽  
Author(s):  
Jun Peng Gao ◽  
Chen Qian Zhang ◽  
Xian Cheng He ◽  
Hong Yi Ma ◽  
Xue Feng An ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Smart Materials ◽  
Shape Recovery ◽  
Epoxy Polymer ◽  
Memory Effects ◽  
Retention Rates ◽  
Thermally Induced ◽  
Shape Memory Effects

We demonstrated a method of fabricating thermosetting epoxy polymer with shape memory effect modified Poly (ether ether ketone) (6F-PEEK) based on the formation of a phase-segregated morphology. The peculiarities of shape memory effects of the epoxy resin modified by 6F-PEEK were investigated. DMA result showed two glass transition temperatures in this blended material. The cured epoxy phase showing high Tg of 223oC acted as hard-segment-forming phase the and was responsible for the permanent shape. The 6F-PEEK can be used as switching phase for a thermally induced shape-memory effect. The transition temperature (Ttran) was 150oC, which was between the Tg of cured epoxy and 6F-PEEK. At the special concentrations of 6F-PEEK, the shape memory effect accompanied by a significant increase in volume was observed. The highest shape memory effect was obtained for the blended material with 25.00 wt% of 6F-PEEK. The shape retention rates and the shape recovery rates were 96-99% and 100%, respectively. The times of shape-recovery were all defined in 2 min. The mechanism of shape memory effects and the mechanical properties of the cured resin were discussed.

Stress-strain behavior of Cu-Al-Ni single-crystal shape memory alloy at high temperature: shape memory effects

2004 ◽  
Author(s):  
Ganesh K. Kannarpady ◽  
Steve Trigwell ◽  
Abhijit Bhattacharyya ◽  
Ivan Viahhi ◽  
Sergei Pulnev
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Single Crystal ◽  
Shape Memory ◽  
Memory Effects ◽  
Crystal Shape ◽  
Stress Strain ◽  
Strain Behavior ◽  
Shape Memory Effects

scholarly journals Multiwalled Carbon Nanotube Reinforced Bio-Based Benzoxazine/Epoxy Composites with NIR-Laser Stimulated Shape Memory Effects

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 881 ◽  
Author(s):  
Wassika Prasomsin ◽  
Tewarak Parnklang ◽  
Chaweewan Sapcharoenkun ◽  
Sunan Tiptipakorn ◽  
Sarawut Rimdusit
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Recovery Process ◽  
Memory Effects ◽  
Molecular Characteristics ◽  
Multiwalled Carbon ◽  
Dynamic Mechanical ◽  
Good Shape ◽  
Shape Memory Effects ◽  
Nir Laser

Smart materials with light-actuated shape memory effects are developed from renewable resources in this work. Bio-based benzoxazine resin is prepared from vanillin, furfurylamine, and paraformaldehyde by utilizing the Mannich-like condensation. Vanillin-furfurylamine-containing benzoxazine resin (V-fa) is subsequently copolymerized with epoxidized castor oil (ECO). When the copolymer is reinforced with multiwalled carbon nanotubes (MWCNTs), the resulting composite exhibits shape memory effects. Molecular characteristics of V-fa resin, ECO, and V-fa/ECO copolymers are obtained from Fourier transform infrared (FT-IR) spectroscopy. Curing behavior of V-fa/ECO copolymers is investigated by differential scanning calorimetry. Dynamic mechanical properties of MWCNT reinforced V-fa/ECO composites are determined by dynamic mechanical analysis. Morphological details and distribution of MWCNTs within the copolymer matrix are characterized by transmission electron microscopy. Shape memory performances of MWCNT reinforced V-fa/ECO composites are studied by shape memory tests performed with a universal testing machine. After a significant deformation to a temporary shape, the composites can be recovered to the original shape by near-infrared (NIR) laser actuation. The shape recovery process can be stimulated at a specific site of the composite simply by focusing NIR laser to that site. The shape recovery time of the composites under NIR actuation is four times faster than the shape recovery process under conventional thermal activation. Furthermore, the composites possess good shape fixity and good shape recovery under NIR actuation.

scholarly journals Harnessing reversible dry adhesion using shape memory polymer microparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19616-19622
Author(s):  
Wenbing Li ◽  
Junhao Liu ◽  
Wanting Wei ◽  
Kun Qian
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Memory Effects ◽  
Reversible Adhesion ◽  
Dry Adhesion ◽  
Bonding Property ◽  
Shape Memory Effects ◽  
Polymer Microparticles

Shape memory polymers can provide excellent bonding property because of their shape memory effects. This paper proposes an adhesive unit that is capable of repeatable smart adhesion and exhibits reversible adhesion under heating.

Effects of ionic liquid types on the tribological, mechanical, and thermal properties of ionic liquid modified graphene/polyimide shape memory composites

2021 ◽  
pp. 095400832199676
Author(s):  
Yuting Ouyang ◽  
Qiu Zhang ◽  
Xiukun Liu ◽  
Ruan Hong ◽  
Xu Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Composite Materials ◽  
Shape Memory ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Graphene Nanosheets ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Modified Graphene

Different ionic liquid modified graphene nanosheets (IG) were induced into polyimide (PI) to improve the tribological, thermal, and mechanical properties of shape memory IG/PI composites. The results demonstrated that when using 1-aminoethyl-3-methylimidazole bromide to modify graphene nanosheets (IG-1), the laser-driven shape recovery rate of IG-1/PI composites (IGPI-1) reached 73.02%, which was 49.36% higher than that of pure PI. In addition, the IGPI-1 composite materials reached the maximum shape recovery rate within 15 s. Additionally, under dry sliding, the addition of IG can significantly improve the tribological properties of composite materials. IGPI-1 exhibited the best self-lubricating properties. Compared with pure PI, the friction coefficient (0.19) and wear rate (2.62 × 10–5) mm3/Nm) were reduced by 44.1% and 24.2%, respectively, and the T10% of IGPI-1 increased by 32.2°C. The Tg of IGPI-1 reached 256.5°C, which was 8.4°C higher than that of pure PI. In addition, the tensile strength and modulus of IGPI-1 reached 82.3 MPa and 1.18 GPa, which were significantly increased by 33.6% and 29.8%, respectively, compared with pure PI. We hope that this work will be helpful for the preparation of shape memory materials with excellent tribological, thermal, and mechanical properties.

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