Shape Memory Alloys for Aerospace, Recent Developments, and New Applications: A Short Review

Abstract

Shape memory alloys (SMAs) show a particular behavior that is the ability to recuperate the original shape while heating above specific critical temperatures (shape memory effect) or to withstand high deformations recoverable while unloading (pseudoelasticity). In many cases the SMAs play the actuator's role. Starting from the origin of the shape memory effect, the mechanical properties of these alloys are illustrated. This paper presents a review of SMAs applications in the aerospace field with particular emphasis on morphing wings (experimental and modeling), tailoring of the orientation and inlet geometry of many propulsion system, variable geometry chevron for thrust and noise optimization, and more in general reduction of power consumption. Space applications are described too: to isolate the micro-vibrations, for low-shock release devices and self-deployable solar sails. Novel configurations and devices are highlighted too.

Keywords: aerospace applications; intelligent systems; nitinol; shape memory alloys; smart structures.

Figure 1

Binary phase diagram of Ti-Ni alloy [7]. Figure 1 Reprinted from Materials, Vol. 12 (5), Chekotu, J.C.; Groarke, R.; O’Toole, K., Brabazon, D., Advances in Selective Laser Melting of Nitinol Shape Memory Alloy Part Production, 2019.

Figure 2

Stress-strain curves for a Ti-50.6Ni alloy showing shape memory effect (a–i) and pseudoelastic effect (j–p) [13]. Figure 2 Reprinted from Scripta Metallurgica, Vol. 15, Miyazaki, S.; Otsuka, K.; Suzuki, Y., Transformation pseudoelasticity and deformation behavior in a Ti-50.6Ni alloy, 1981, with permission from Elsevier.

Figure 3

The SAMPSON F-15 inlet tested in the facility at Langley (NASA) [19]. Figure 3 Available online: https://crgis.ndc.nasa.gov/historic/File:2000-L-00475.jpg.

Figure 4

Various morphing devices employed on the wing airplanes can change, stretching or compressing, the aerodynamic profile [20]. Figure 4 Reprinted from Chinese Journal of Aeronautics, Vol. 32 (4), Chen, Y.; Shen, X; Li, J.; Chen, J., Nonlinear hysteresis identification and compensation based on the discrete Preisach model of an aircraft morphing wing device manipulated by an SMA actuator, 2019, open access.

Figure 5

Variable geometry chevron activated by SMA in the full scale test [23]. Figure 5 Reprinted from Proceedings of the Institution of the Mechanical Engineer, Part. G: Journal of Aerospace Engineering, Vol. 221, Hartl, D.J.; Lagoudas, D.C., Aerospace applications of shape memory alloys, 535–552, 2007, open access.

Figure 6

(a) Sketch of the morphing laminar wing adopting extrados with shape memory alloy (SMA) active element [27]. (b) Scheme of the SMA actuator’s working principle [27]. Figure 6 Reprinted from Physics Procedia, Vol. 10, Brailovski, V.; Terriault, P.; Georges, T.; Coutu, D., SMA Actuators for morphing wings, 197–203, 2010, open access.

Figure 7

Camber change of activated and deactivated airfoil profile [31]. Figure 7 Reprinted from Materials Today Proceedings, Vol. 5, Hattalli, V.L.; Sritvasa, S.R., Wing morphing to improve control performance of an aircraft—An overview and a case study, 21442–21451, 2018, with permission from Elsevier.

Figure 8

Wing model setup in wind tunnel section [34]: Leading edge (Left); Trailing edge (Right). Figure 8 Reprinted from Chinese Journal of Aeronautics, Vol. 30 (1), Koreanski, A.; Gabor, O.S.; Acotto, J.; Brianchon, G.; Portier, G., Botez, R.M.; Mamou, M.; Mebarki, Y., Optimization and design of an aircraft’s morphing wing-tip demonstrator for drag reduction at low speed, Part. II – Experimental validation using Infra-red transition measurement from wind tunnel tests, 164–174, 2017, open access.

Figure 9

Example of infrared results for morphed wing demonstrator without aileron [34]. Figure 9 Reprinted from Chinese Journal of Aeronautics, Vol. 30 (1), Koreanski, A.; Gabor, O.S.; Acotto, J.; Brianchon, G.; Portier, G., Botez, R.M.; Mamou, M.; Mebarki, Y., Optimization and design of an aircraft’s morphing wing-tip demonstrator for drag reduction at low speed, Part. II – Experimental validation using Infra-red transition measurement from wind tunnel tests, 164–174, 2017, open access.

Figure 10

Shape memory alloy actuator (extension) in a morphing wing [35]. Figure 10 Reprinted from Materials Today Proceedings, Vol. 5, Bashir, M.; Rajendram, P.; Sharma, C.; Smrutiranjan, D., Investigation of smart material actuators & aerodynamic optimization of morphing wing, 21069–21075, 2018, with permission of Elsevier.

Figure 11

Shape memory alloys (SMA) mesh washer developed by Kwon et al. (Left) [36]. Pseudoelastic SMA mesh washer (Right) [36]. Figure 11 Reprinted from Cryogenics, Vol. 67, Kwon, S.C; Jeon, S.H.; Oh, H.U., Performance evaluation of spaceborne cryocooler micro-vibration isolation system employing pseudoelastic SMA mesh washer, 19–27, 2015, with permission of Elsevier.

Figure 12

Step of solar sail folding sequence for two different configurations of the SMA actuators [47]: towards inside (a–c) and towards outside (d–f). Figure 12 Reprinted from Actuators, Vol. 8 (2), Boschetto, A.; Bottini, L.; Costanza, G.; Tata, M.E., Shape memory activated self-deployable solar sails: small scale prototypes manufacturing and planarity analysis by 3D laser scanner, Art. N. 38, 2019, open access.

Figure 13

Solar-sail self-deployment experiment under vacuum condition in the bell jar (Left) [48], solar sail with carbon fiber on the frame integrating the SMA (Right) [49]. Figure 13 Reprinted from Aerospace, Vol. 6 (7), Bovesecchi, G.; Corasaniti, S.; Costanza, G.; Tata, M.E., A novel self-deployable solar sail system activated by shape memory alloys, Art. N. 78, 2019, open access e Reprinted from Advances in materials science and engineering, Vol. 2017, Costanza, G.; Leoncini, G.; Quadrini, F.; Tata, M.E. Design and characterization of a small-scale solar sail prototype by integrating NiTi SMA and carbon fibre composite, Art. N. 8467971, 2017, open access.