Pseudoelasticity of Cu-13.8Al-Ni Alloys Containing V and Nb

2008 ◽  
Vol 59 ◽  
pp. 101-107 ◽  
Author(s):  
Rodinei Medeiros Gomes ◽  
Ana Cris R. Veloso ◽  
V.T.L. Buono ◽  
Severino Jackson Guedes de Lima ◽  
Tadeu Antonio de Azevedo Melo
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Shape Recovery ◽  
Cold Water ◽  
Low Cost ◽  
Tensile Tests ◽  
Grain Refiner ◽  
Good Shape ◽  
Potential Applications ◽  
Superelastic Behavior

Polycrystalline copper-based shape memory alloys have been of particular interest in relation to Ni-Ti because of their low cost and good shape memory effect. Nevertheless the absence of a pronounced pseudoelasticity effect restricts the number of potential applications. In this work, the influence of Nb and V on the microstructure and the mechanical properties was investigated. Samples of Cu-13.8 Al-Ni containing V and Nb alloy were prepared by induction and solution treated at 850°C and then further quenched into cold water. The addition of Nb and V promotes the formation of precipitates which act as grain refiner and subsequently improve the mechanical properties. The tensile tests were performed at temperatures slightly inferior to Mf and superior to Af, to investigate the shape recovery and pseudoelasticity, respectively. Based on the analyses of the Cu-13,8Al-2Ni-1Nb (wt%) alloy was detected rupture strains greater than 14%, besides observation of the superelasticity of these alloys and quantification of this property by means of cycling, from 0 to strains between 1 and 7%. The studies performed on alloy Cu-13.8Al- 3,5Ni-1V (wt%) made it possible to determine rupture strains in the order of 3% and its superelastic behavior through cycling for deformations between 1 and 3%.

Effect of Aging on Mechanical Properties of Ti-Mo-Al Biomedical Shape Memory Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 2150-2153 ◽  
Author(s):  
Hideki Hosoda ◽  
Makoto Taniguchi ◽  
Tomonari Inamura ◽  
Hiroyasu Kanetaka ◽  
Shuichi Miyazaki
Keyword(s):  
Mechanical Properties ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Tensile Tests ◽  
Single Step ◽  
Two Phase ◽  
Solution Treated

Effects of single- and multi-step aging on mechanical properties and shape memory properties of Ti-6Mo-8Al (mol%) biomedical shape memory alloy were studied using tensile tests at room temperature (RT). The solution-treated alloy at RT was two phase of bcc β and martensite α". Tensile tests revealed that the solution-treated alloy exhibited good shape memory effect. As for the single-step aging, (1) pseudoelastic shape recovery by unloading was observed after aging at 623K, (2) the alloy became brittle after aging at 773K due to ω embrittlement, and (3) strength was improved with small shape memory effect by aging at 1023K. On the other hand, after a multistep aging at 773K-1023K-1123K, the alloy was strengthened and showed perfect shape recovery. The improvement must be achieved by the formation of fine and uniform hcp α precipitates.

Shape-Memory Properties of Nanocomposites based on Poly(ω-pentadecalactone) and Magnetic Nanoparticles

2012 ◽  
Vol 1403 ◽  
Author(s):  
M. Y. Razzaq ◽  
M. Behl ◽  
A. Lendlein
Keyword(s):  
Mechanical Properties ◽  
Magnetic Nanoparticles ◽  
Shape Memory ◽  
Shape Recovery ◽  
Weight Content ◽  
Magnetic Heating ◽  
Shape Memory Properties ◽  
Potential Applications ◽  
Alternating Magnetic Fields ◽  
Shape Fixity

ABSTRACTMagneto-sensitive shape-memory polymers (SMP) obtained by incorporating magnetic nanoparticles in a SMP matrix are an emerging class of multifunctional materials. The incorporation of the nanoparticles enhanced the mechanical properties and in addition enabled remote actuation by exposure to alternating magnetic fields. Here, we report on the thermallyinduced shape-memory properties of such magneto-sensitive nanocomposites based on poly(ω- pentadecalactone) (PPDL) switching segments and magnetic nanoparticles. A series of nanocomposites were prepared by crosslinking of poly(ω-pentadecalactone)dimethacrylate (Mn = 2800 g·mol-1and 5100 g·mol-1) in the presence of silica encapsulated magnetic nanoparticles. The silica shell of the nanoparticles was selected to enhance the distribution and compatibility of the nanoparticles with the polymer matrix. Thermal and mechanical properties of the nanocomposites were explored as a function of PPDL chain length and nanoparticle weight content. All nanocomposites exhibited excellent shape-memory properties with shape fixity rates between 86% and 93% and shape recovery rates above 97%. Potential applications for such shape-memory nanocomposites include smart implants, medical instruments, which could be controlled on demand by thermal or indirect magnetic heating.

scholarly journals 4D Printing of Shape Memory Polymer via Liquid Crystal Display Stereolithography

2020 ◽  
Author(s):  
Wubing Shan ◽  
Yifan Chen ◽  
Hu Mo ◽  
Shigang Qin ◽  
Peng Liu
Keyword(s):  
Liquid Crystal ◽  
3D Printing ◽  
Shape Memory ◽  
Shape Recovery ◽  
Liquid Crystal Display ◽  
Low Cost ◽  
Shape Memory Polymer ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
High Efficient

In this study, we report a new epoxy acrylate based shape memory polymer(SMP) fabricated by Liquid crystal display (LCD) Stereolithographic 3D printing. The printed 3D object has a high resolution and high transparency in visible light region. The uniaxial tensile tests showed enhanced tensile toughness and tunable mechanical properties. The fix-recovery and cycle tests indicated high shape recovery properties including high shape recovery rate and excellent cycling stability. In addition, a smart electrical valve actuator was fabricated that can be used in fast heat or electricity responsive electrical circuits. LCD 3D printing provides a low-cost and high efficient way to fabricate fast responsive SMP, which can be used in wide applications in various fields on aerospace engineering, biomedical devices, soft robots and electronic devices.

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.

Heat Treatment Effects on Static and Dynamic Mechanical Properties of Sintered SINT D30 Powder Metal

2013 ◽  
Vol 592-593 ◽  
pp. 643-646 ◽  
Author(s):  
Marko Šori ◽  
Tomaž Verlak ◽  
Srečko Glodež
Keyword(s):  
Mechanical Properties ◽  
Complex Geometry ◽  
Low Cost ◽  
Surface Hardness ◽  
Load Ratio ◽  
Tensile Tests ◽  
Test Machine ◽  
Strain Diagram ◽  
Powder Metal ◽  
Sintered Steel

Low cost, low material waste and good accuracy in components with complex geometry are the main reasons for powder metallurgy to be considered as a promising manufacturing process for the future. Like wrought steel, sintered steel can also be heat treated to increase surface hardness and to improve strength. This paper compares mechanical properties of the hardened sintered steel with the sintered steel of the same powder metal SINT D30. Firstly, the static strength of both samples is determined by quasi-static tensile tests. Results are compared in stress strain diagram and they show that the tensile strength of the hardened sintered steel SINT D30 can surpass 700 MPa. The main focus of this study is however fatigue behaviour of the sintered steel. Both sets of samples are tested on a pulsating test machine with the load ratio of R = 0. The first sample is subjected to a load that corresponds to 90 % of the yield strength and is then gradually lowered to achieve one million stress cycles without breakage. Obtained results are then presented as Wöhler curves and compared in S-N diagram.

Effect of Nitrogen Addition on TiNi Shape Memory Alloys

2020 ◽  
Vol 12 (9) ◽  
pp. 1403-1408
Author(s):  
Izaz Ur Rehman ◽  
Tae-Hyun Nam
Keyword(s):  
Mechanical Properties ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Tensile Tests ◽  
Nitrogen Addition ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Transformation Temperatures ◽  
Arc Melting ◽  
Type Phase

In present paper we will show how nitrogen effects microstructures, transformation temperatures, and mechanical properties of equiatomic Ti50–Ni50 and Ti-rich Ti51–Ni49 binary shape memory alloys. 0.5 at.% of nitrogen was added to prepare Ti50–Ni49.5–N0.5, and Ti51–Ni48.5–N0.5 (at.%) alloys by arc-melting. Microstructures were investigated by scanning electron microscope (SEM), phase constitutions were investigated by X-ray diffraction (XRD), transformation temperatures were investigated by differential scanning calorimeter (DSC) and mechanical properties were tested by tensile tests. Solutions treated Ti–Ni–N shape memory alloys contain TiNi matrix without nitrogen, Ti2Ni type phase containing a small amount of nitrogen and a new Ti2N type phase containing a small amount of nickel. Compared with Ti50–Ni50 and Ti51–Ni49 binary alloys, the martensitic transformation starts temperatures (Ms) of Ti50–Ni49.5–N0.5 and Ti51–Ni48.5–N0.5 ternary alloys decreased from 63.4 °C to 41.6 °C and from 85.3 °C to 79.4 °C, respectively. By adding N, fracture strain decreased and incomplete superelasticity was observed.

Tensile properties of the FFF-processed thermoplastic polyurethane (TPU) elastomer

2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Low Cost ◽  
Thermoplastic Polyurethane ◽  
High Strength ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Fused Filament Fabrication ◽  
Raster Angle ◽  
Manufacturing Techniques

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.

scholarly journals Nanoscale Mechanical Properties of Nanoindented Ni48.8Mn27.2Ga24 Ferromagnetic Shape Memory Thin Film

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Xiaofei Fu ◽  
Chao Liu ◽  
Xili Lu ◽  
Xianli Li ◽  
Jingwei Lv ◽  
...  
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Martensitic Transformation ◽  
Magnetron Sputtering ◽  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Recovery Ratio ◽  
Dc Magnetron Sputtering ◽  
Ferromagnetic Shape Memory

The structure and nanoscale mechanical properties of Ni48.8Mn27.2Ga24 thin film fabricated by DC magnetron sputtering are investigated systematically. The thin film has the austenite state at room temperature with the L21 Hesuler structure. During nanoindentation, stress-induced martensitic transformation occurs on the nanoscale for the film annealed at 823 K for 1 hour and the shape recovery ratio is up to 85.3%. The associated mechanism is discussed.

Origami-inspired shape memory dual-matrix composite structures

2019 ◽  
Vol 30 (17) ◽  
pp. 2639-2647
Author(s):  
O-Hyun Kwon ◽  
Jin-Ho Roh
Keyword(s):  
Shape Memory ◽  
Polymer Composite ◽  
Matrix Composite ◽  
Composite Structures ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Morphing Structure ◽  
Composite Skins

A sandwiched morphing structure is developed using an Origami-inspired shape memory dual-matrix composite core and shape memory polymer composite skins. The geometric parameters of the morphing structure are designed to have a zero Poisson’s ratio. In addition, an analytical model is developed to analyze the three-dimensional morphing structure easily. The shape memory dual-matrix composites are fabricated with woven fabrics based on the shape memory polymers, and an epoxy matrix is used to ensure a flexible and shape-recoverable structure. The shape recoverability of the shape memory polymer composite skins is verified by measuring the shape recovery ratio at various temperatures. Based on the tensile tests for the shape memory polymer composite skins and shape memory polymer hinges, it is found that the morphing structure can be highly flexible depending on temperature. Finally, the bending and shape recovery behaviors of the morphing structure are demonstrated.

Shape Memory Behavior and Mechanical Properties of NiMn and Ni(Mn,X) Alloys

1991 ◽  
Vol 246 ◽  
Author(s):  
W.S. Yang ◽  
D.E. Mikkola
Keyword(s):  
Mechanical Properties ◽  
Transition Temperature ◽  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Transformation Temperatures ◽  
Room Temperature Ductility ◽  
Substitutional Solute ◽  
Ternary Element ◽  
High Transition

AbstractPotential high transition temperature shape memory alloys based on NiMn have been studied with emphasis on the shape recovery, transformation temperatures and mechanical properties. Binary NiMn, which has been reported to be brittle, has a low shape recovery, but this can be increased with Al or Ti additions. Also, the transformation temperature can be changed and the room temperature ductility improved by ternary element additions. The various substitutional solute characteristics affecting the shape recovery, the transformation temperatures, and the ductility have been examined.

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