Application of a NiTi alloy two-way shape memory helical coil for a versatile insulating jacket

Preliminary study on the thermomechanical treatment of shape memory alloys for applications in clothing protecting against heat

“…The average coefficients of variance for M1 were 51.5% and for M2 12.2%. The obtained results are in good agreement with the results published by Yoo et al, 10 Scherngell and Kneissl 18,19 and Miyazaki et al 20 They attributed the reduction in the recovery rate to the introduction, rearrangement and/or annihilation of dislocations (developed in an austenitic matrix in the TT process) during repeated motion of the parent-martensite interface. This, in turn, leads to a reduction in the amount of usefully oriented martensite.…”

“…The change in the ambient temperature caused the expansion of the springs, which in turn caused an increase in thermal insulation of clothing thus allowing obtaining better protective properties against either high temperature 9 or low temperature. 10 Implementation of NiTi elements into the firefighters' suits caused around 30% increase in protection time, 9 while versatile insulating jacket with NiTi improved human sensation during exposure to cold. 10 What directly affects applicability of NiTi elements for active regulation of air gap between the clothing layers is a specific procedure of TT they are being subjected to.…”

“…10 Implementation of NiTi elements into the firefighters' suits caused around 30% increase in protection time, 9 while versatile insulating jacket with NiTi improved human sensation during exposure to cold. 10 What directly affects applicability of NiTi elements for active regulation of air gap between the clothing layers is a specific procedure of TT they are being subjected to. In particular, it is necessary to select the appropriate annealing temperatures and methods of thermomechanical cycling that would ensure activation of the element in a specific temperature range, desired changes in shape and satisfactory durability.…”

Development of Smart Textile Materials with Shape Memory Alloys for Application in Protective Clothing

“…The transformation takes place between the austenite and martensite phases [2][3][4]. An important feature of SMAs that can be used in smart protective clothing is the two-way shape memory effect (TWSME), which results from appropriately conducted thermomechanical treatment (TT) [5][6][7][8][9]. The element made of SMA, having a particular shape in the high-temperature phase, after cooling to the temperature specific for the low-temperature phase of the alloy, adopts another given shape.…”

“…The ability of SMAs to change their shape, size, or internal structure under the influence of a particular stimulus is the subject of intensive application research [11]. The works in this area are also associated with their applications in textiles and clothing [5,[12][13][14][15][16][17][18][19][20][21][22][23][24]. For example, the active knits made of SMA wire have a great potential for use as innovative actuators, because these materials thanks to the hierarchically organized structure is able to produce complex three-dimensional actuation motions [25].…”