A shape memory porous sponge with tunability in both surface wettability and pore size for smart molecule release

In this work, the influence of microwave sintering time and temperature on the microstructure characterisation, and thermal and mechanical behaviours of Ti–30Ta were investigated. The relative densities of Ti–30Ta samples were in the range of 65–72% and as the sintering times/temperatures increased, the relative density decreased. The pore size averages were in the range of 6–17 µm with different sintering parameters, for instance the smallest pore size of 6.8 µm was observed after being sintered at 900 ℃ for 30 min (Ta2). Two morphologies of plate-like (P) and needle-like (N) structures were observed, as well as two regions – dark region (Ti-rich region) and bright region (Ta-rich region), also two phases – β and α. The DSC results revealed that the Ms to Mf transformation range was 98.86 to 80.5 ℃, respectively, while the range of As to Af transformation was about −22.35 to 92 ℃, respectively. The maximum fracture strength and its strain were acquired in the sintered sample of 900 ℃ for 30 min. The total strain recovery (ɛT) was improved linearly as the sintering temperature increased, correspondingly, the best ɛT was implied in Ti–Ta shape memory alloys after being sintered at 1000 ℃ for 30 min (Ta4).

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Nano-porous shape memory membrane: Fabrication based on double bicontinuous structures in ternary blend and pore-size manipulation by macroscopic deformation

Applied Surface Science ◽

10.1016/j.apsusc.2019.02.205 ◽

2019 ◽

Vol 480 ◽

pp. 276-280 ◽

Cited By ~ 2

Author(s):

Qiucheng Yang ◽

Tao Wang ◽

Liang Zhang ◽

Jifei Zhang ◽

Fei Wang ◽

...

Keyword(s):

Shape Memory ◽

Pore Size ◽

Ternary Blend ◽

Membrane Fabrication ◽

Macroscopic Deformation

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Phase Field Simulation of Ni4Ti3 Precipitation in Porous NiTi Shape Memory Alloys under Applied Stresses

Materials Science Forum ◽

10.4028/www.scientific.net/msf.654-656.1504 ◽

2010 ◽

Vol 654-656 ◽

pp. 1504-1507 ◽

Cited By ~ 1

Author(s):

Chang Bo Ke ◽

Xiao Ma ◽

Xin Ping Zhang

Keyword(s):

Shape Memory ◽

Pore Size ◽

Compressive Stress ◽

Applied Stress ◽

Phase Field ◽

Particle Distribution ◽

Field Approach ◽

Field Simulation ◽

Niti Shape Memory Alloys ◽

Applied Stresses

This study presents the simulation of evolution of Ni4Ti3 variants during stress-assisted aging of NiTi alloys containing nano-scale pores with different sizes, by using phase field approach. The simulation shows that the higher level of applied stress can cause more Ni4Ti3 particles precipitated around pores than that of lower level stress, regardless of pore size; the large pores can “capture” more precipitates while less particles precipitated around the small pores. Moreover, the precipitation of Ni4Ti3 particles exhibits different regional preferences near pores, which means the unixial compressive stress can result in inhomogeneous Ni4Ti3 particle distribution.

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