Shape memory alloys in textile
- 1. Shape Memory Alloys in Textile Properties, smart textiles and applications
- 2. Introduction Properties of shape memory alloys Manufacturing of SMAs Types of shape memory alloys Mechanism of Shape Memory Alloy Smart Textile Content
- 3. Shape Memory alloy in Yarns SMP Fibers SMP Yarns and Fabrics SMP Programming Shape-Memory Applications in Textile Using of shape memory alloy in Orthodontics Content
- 4. JensMartensson Introduction Shape memory alloys 1- The shape memory effect characterized by the capability of a material to be deformed at a low temperature and then to revert to its prior shape upon heating above a temperature associated with the particular alloy. 2- The second is super plasticity which is the ability of a material to exhibit large recoverable strains (up to approximately 15%), while deformed within a range of temperature characteristic of a specific alloy. 4
- 5. Schematic illustration of atomic arrangements during martensitic transformation. P: parent phase, M: martensitic phase subscripts A and B stand for the martensite crystals with different shear directions Mechanism of Shape Memory Alloy
- 6. JensMartensson 6 Different between SMA and SE mechanism Super elastic mechanismSMA mechanism
- 7. JensMartensson 7 Properties of SMAs Shape Memory EffectPseudo elasticity The SMA reverts to its original shape when the applied deformation stress is removed. It is done by the subsequent recovery of the deformation strain when the stress is removed Shape memory effect retains a deformed state after the removal of an external force and then recovers to its original shape upon heating
- 8. JensMartensson 8 Manufacture of SMAs The shape memory alloys (SMAs) are considered as difficult to machine (DTM) materials. ISMAs possess poor machinability that subsequently lead to the problems like progressive tool wear, deterioration of surface quality, burr formation, and high consumption of energy and resources, which are encountered during their machining. For example, Fig shows some drawbacks while machining Nitinol (NiTi) SMA during conventional grinding and turning processes.
- 9. JensMartensson 9 Embedding of SMA wires in textile structures • Used for embedding SMA wires into a textile structure is stitching, as used by Leenders to produce her “moving textiles”. • Another method of embedding SMA wires is via a weaving process, using a hand-weaving loom, as in most of the cases reported in literature
- 10. Types of shape memory alloys 1. Iron-based alloy Fe–Mn–Si 2. Copper-based SMAs such as Cu–Zn– Al; Cu–Al–Ni, Cu–Al–Ni–Mn, and Cu–Sn 3. Nickel–Titanium based alloys such as NiTi, NiTiCu, NiTiPd, NiTiFe, NiTiNb, NiFeGa, and NiTiCo 4. Kovar (29% Ni, 17% Co, 0.3% Si, 0.1% C and Fe balance) 5. High-temperature shape memory alloys such as TiNiPd, TiNiPt, NiTiHf, NiTiZr, ZrRh, ZrCu, ZrCuNiCo, ZrCuNiCoTi, TiMo, TiNb, TiTa, TiAu, UNb, TaRu, NbRu, and FeMnSi 6. Magnetic shape memory alloys, namely, NiMnGa, FePd, NiMnAl, FePt, Dy, Tb, LaSrCuO, ReCu, NiMnIn, and CoNiGa
- 11. JensMartensson 11 Shape Memory alloy in Yarns • Yarns can be designed with trained Ni-Ti SMA wires as core component, wrapped with conventional fibers such as polyester, viscose and polyamide
- 12. JensMartensson 12 Shape Memory alloy in Yarns 1. Fabric Development Experimental fabrics have been made of SMA wire and/or of SMA wrapped spun yarns.
- 13. JensMartensson 13 Shape Memory alloy in Yarns 2. Programming SMA SMAs are normally ‘trained’ to remember one or two particular shapes while they are in the austenite phase. As conventional textile materials are not able to withstand the high temperatures required for the programming, use of SMAs in textiles normally requires programming of the alloy before yarn spinning, weaving or knitting.
- 14. Smart Textile Smart textiles are textile products that can detect and react to an external effect or effect change (light, heat, pressure, electromagnetic waves, sound and ultrasonic waves, motion etc.). The shape memory effect is the ability to recover the original shape when a material is activated with appropriate stimuli.
- 15. Smart Textile Shape-memory polymers (SMPs) SMPs can sense and respond to external stimuli such as temperature, pH, chemicals, and light in a predetermined way These materials have various elasticities from hard glass to soft rubber. SMPs have very low cost in comparison with Shape-Memory Alloys.
- 16. JensMartensson 16 Differences Between Shape Memory Polymers and Alloys • The ability to reverse completely to their original pre-determined shape • better mechanical properties. Shape Memory Polymers • SMPs are lighter • easy to process • economical compared to SMA’s • high shape transformations and high recovery, • soft touching and the adjustment of key temperature • Some SMP’s are also biodegradable, which can be useful in medical applications Shape Memory Alloys
- 17. JensMartensson 17 SMP Fibers • Macro-scaled shape memory fibers can be produced with wet, dry spinning • And melt spinning methods Shape memory polyurethane (SMPU) fibers were prepared for the first time in 2006 with wet-spinning
- 18. JensMartensson 18 SMP Fibers Wet-Spinning process of fibers Melt-Spinning process of fibers
- 19. JensMartensson 19 SMP Yarns and Fabrics Shape memory fibers can be turned into yarns together with other fibers by using friction or ring technology. The yarns were woven and knitted into three-dimensionally changing structures. Knitting and weaving of the material did not raise difficulties, as in the case of knitting the SMA.
- 20. JensMartensson 20 SMP Programming Unlike SMA, which has to be programmed before incorporation in the textile structure because of the high treatment temperature, SMPs are treated after their incorporation into yarns and fabrics.
- 21. Shape memory recovery of smart textile having SMA spring varied with temperature when T=50oC: (a) 0 s; (b) 10 s; (c) 20 s Shape-Memory Applications in Textile
- 22. An intelligent window curtain application Shape-Memory Applications in Textile
- 23. Shape memory recovery of SMP composite woven uniformly and densely of SMP yarn at 50oC with recovery time (a) 0 s, (b) 15 s, and (c) 30 s" Shape-Memory Applications in Textile
- 24. JensMartensson Other applications • Fashion and entertainment • Health care • Life belt • Life jacket • Military defense • Sports wear • Purpose clothing • Future development 24 Shape-Memory Applications in Textile
- 25. Conclusion Shape memory materials (SMMs) are a set of materials that, due to external stimulus, can change their shape from some temporary deformed shape to a previously ‘programmed’ shape. The shape change is activated most often by changing the surrounding temperature, but with certain materials also stress, magnetic field, electric field, pH-value, UV light and even water can be the triggering stimulus.
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